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PostPosted: Wed Jun 15, 2022 6:57 pm 
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Future Club member hopefully!
Future Club member hopefully!

Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
Quote:
Droopy exhaust? not especially, or at least not by accident! the downpipe location is a tad low because there is very little space between the fat GM trans and the longitudinal chassis rail. This complicated by the joint between downpipe and centre box ending up directly below the trans crossmember. The final event in this causational cascade being the exceptionally high and steep sleeping policemen on the campsite! A re-engineered clamp, along with another 1/2" or so of ground clearance from the 185/60/15 tyres, when I get them, will fix this.

I have never embarked on any exotic engine transplants from one vehicle marque to another, although I have transplanted a modified, hybrid, 1911 cm³ displacement, VW 17/1800 Type 4 style air-cooled engine (based upon a 1972 VW 412LE Variant fuel-injected, 1679 cm³ displacement engine) & 1974 VW 1800 Type 2 transaxle, in the 1973 VW “1600” Type 2, in place of the original 1584 cm³ displacement, VW 1600 Type 1 Beetle style air-cooled engine & 1973 VW 1600 Type 2 transaxle.

The real challenge, will be to substitute a 1983~92 VW Transporter T3, five-speed transaxle (with side-mounted gear-selector rather than front-mounted); assuming it’s feasible and I can find an affordable specimen in good operating condition with all the necessary ancillary components.

Many people get caught out by sleeping policeman (aka speed humps)! My friend who towed a caravan using a Rover 800 and later a Rover 75, commonly grounded his towing bracket when negotiating campsite speed humps.

The speed humps in Canvey Island town centre often catch people unawares and I commonly hear the front spoilers on low-slung modern cars scraping over them, including the 21st Century “Minis” built by BMW in Oxforshire, even when negotiated at a snail’s pace. One of Canvey Island’s industrial estates also has speed humps, which painfully jarred my spine even when negotiated at a slow walking speed, whilst travelling in the back seat of my friend’s SEAT Arosa; a car which had ridiculously low-profile tyres in my opinion, for an urban runabout.

In contrast, whilst driving at circa 40~50 mph, in a Toyota Hiace Mk.1 based motor-caravan in 1979, along a country road somewhere in Norfolk or Suffolk, I entered a small village, whose 30 mph restriction sign was obscured by tree branches & foliage, where I encountered a speed hump at considerably more than 30 mph. Apart from the audible thump-thump sound, as the front & rear tyres passed over the speed hump, I barely noticed any effect, despite sitting over the front wheels of this forward-control vehicle. I envisage that the 1973 VW Type 2 based motor-caravan, would similarly have shrugged off the effect of this speed hump; even with 65-Series, 215/65 R16C tyres on 7 x 16 inch alloy wheels!

If you were to substitute a set of 185/65 R15 tyres in preference to 185/60 R15 tyres, in place of your current 185/55 R15 tyres, this would give you twice as much increase (18•5 mm instead of 9•25 mm) in ground clearance and probably increase ride comfort, which would reduce fatigue on long journeys. It might even give you further improved fuel economy!

185/55 R15 tyres – external radius = 292•25 mm

185/60 R15 tyres – external radius = 301•5 mm (9•25 mm more than 185/55 R15)

185/65 R15 tyres – external radius = 310•75 mm (18•5 mm more than 185/55 R15)

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If I place my 1000 mm long STANLEY aluminium builder's spirit-level across the sidewall of the tyres there is a large gap between the underside of the spirit-level and the closest part of the wheel centres as follows:

Dolomite Sprint wheel (no centre-cap) & 185/70 R13 tyre - 30 mm gap

MG 2000 Maestro wheel & 185/55 R15 tyre - 23 mm gap
Quote:
I'm surprised the gap twixt wheel centre and board is THAT big, but i'll take your word for it, i've not measured it.

I was a little surprised too, but I assure you it’s true!

Unless one placed a relatively incompressible pad between the wheel centre and the hardboard cover to provide additional support, the wheel centre would provide absolutely no support for heavy luggage above, and would potentially risk damage to the cover and wheel. This is why I intend to fabricate a self-supporting plywood lid, which will be supported by the spare-wheel rim and allow me to safely use the spare-wheel to provide storage for emergency equipment, spares and/or tools.

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And i'm aware of the VW's clever tyre pressure powered washers, having done 2 years on VW in the days when one simply couldn't buy a water cooled one! But I confess I hadn't considered using the bits as an extension to the tyre valve. Having said that, i've also seen valves designed for twin rear wheel trucks that double back through the wheel. However, one of those would be worse than useless once fitted to the car!

My father had a 1964 VW 1200 Type 1 Beetle from 1964 to 1968. Those air-pressurised windscreen washers were certainly a great deal more effective than the manually-pumped windscreen washer kit that he retro-fitted to his previous car; a late-1940s vintage Morris 8 Series E, in which we made the twice-yearly, circa 12 hour duration, circa 420 mile pilgrimage in one day, between London and Dundee, from 1956 to 1964. The same journey in the VW Beetle was quicker and more comfortable!

In the late-1970s, as part of one of my student vacation jobs, I was obliged to drive a Leyland 440FG 2½ tonner, with double rear wheels, so I am familiar with the tyre-inflation valve-stems for the inboard rear wheels, which would not have served my purpose for the Toledo’s spare wheel. In addition to the VWs’ flexible rubber hose connections with female, screw-on Schräder-valve fitting, there was also a long flexible nylon tube with female, screw-on Schräder-valve fitting, that I think was used on the VW Type 4 (i.e. VW 411 & 412) Fastback and/or Variant, but it wasn’t practical to shorten it. I still have it somewhere!?!

I have long been involved in adapting things for uses which differ from their original intended purposes, including some M10 x 1•0 mm electrical fittings, M10 x 1•0 mm hydraulic brake fittings and M10 x 1•0 mm valve-tappet adjustment screws, that I adapted and used in combination, for my 1973 VW Type 2’s oil-pressure gauge-sender installation!

Nigel A. Skeet, “How to: Fitting an Oil-Pressure Gauge-Sender, Installation Adapter, to the Type 4 Engine”, Volkswagen Camper & Commercial, Jazz Publishing, Issue 17, Winter 2004, Pages 44~45

https://www.thesamba.com/vw/forum/album ... id=1991575

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https://www.thesamba.com/vw/forum/album ... id=1991576

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I also modified and adapted the unusual cross-over-arm, double-linkage, pantograph rear window wiper from an early-1980s vintage, Vauxhall Astra Mk.1 estate car, for use on my 1973 VW Type 2’s rear-hatch window. Alternatively, I could have used the similar rear-window wiper from a Vauxhall Chevette estate car instead. With hindsight, I might have used slightly different components from both Vauxhall estate cars, to create an even better VW Type 2 rear-window wiper system.

Nigel Skeet, "A Clean Sweep", Workshop, VW Motoring, Warner's Publishing Group, December 1996, Pages 85~86

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I’m on the lookout for a compatible spare GM-SWF rear-window wiper motor, so if you come across one I would be pleased to hear from you. Complete rear-window wiper systems from either a Vauxhall Astra Mk.1 estate car or Vauxhall Chevette estate car, would be of interest to some fellow 1968~79 VW Type 2 owners, including a few in North America.

Other Vauxhall related components of potential interest, are the small oval audio-speakers (Blaupunkt brand I think), of the size & shape that were used under the rear plastic mouldings in Vauxhall Astra Mk.1 hatchbacks, adjacent to the fold-down rear parcel shelf. I think these would fit neatly in the narrow strips of plywood headlining adjacent to the elevating-roof-access, roof-aperture of my 1973 VW Type 2 motor-caravan.

Quote:
I'm no stranger to serious long distance driving having more than once driven to Penzance and back in a day, plus of course clocking up around 800 of the 2200 miles we covered in the 48 hours of the 2018 RBRR. The 127 miles to the caravan, largely on the M5, is little more than a "Milk Run" for me and I would expect it to be the same situation for the Dolomega. The car certainly took the outbound trip in it's stride despite atrocious weather and delivered somewhere in the region of 40mpg in the process, considerably more than the Picasso's pretty awful 31mpg motorway average! But I take nothing for granted, the car had covered less than 1400 miles since built, at departure time, snagging is by no means over yet!

I don’t know what the 2018 RBRR is or was!?! I do so loathe undefined abbreviations & acronyms! :evil:

Apart from my family’s twice yearly, circa 420 mile pilgrimages between London and Dundee during 1956 to 1965, all of my long-distance driving has been in motor-caravans in the British Isles, Europe, southern Africa and the USA; including several hours of late-afternoon & evening in thick fog, driving home in the 1973 VW 1600 Type 2 motor-caravan from Switzerland through France, during our 1980 summer touring holiday. Visibility varied between 50 and 100 metres, in which I was driving on dipped, 60/55W quartz-halogen, white-light headlamps (an upgrade I made in 1976), and was constantly being flashed by irritated French drivers using yellow-light headlamps, which were obligatory in those days; but not for tourists driving non-French registered vehicles.

There was nowhere I could safely pull off the road and stop in the fog, so I just kept driving for hour after hour, until late in the evening, when I came upon a very large area of gravel, set back from a minor road junction, where I was able to pull off and stop for the night. Fortunately I didn’t run out of petrol, having seen no petrol filling stations en route! Recalling the reflected glare from dipped headlamps and the virtual invisibility of red tail lights in thick fog at any significant distance, I bemoaned my lack of proper front & rear fog lights, which I have since regarded as vital safety equipment for ALL vehicles!

Quote:
I'm quite sure the arches WOULD have rubbed on the 185/55 shod MGF 15s if I hadn't already partially relieved them in an attempt to clear the JBW 14's. This seems to be a car-by-car thing, I know of some people who've had this particular combo clear without modification, others don't! The Carledo only barely failed to clear 205/50s. The subtle difference in design between the long and short tailed car's rear arches does favour (oddly) the Toledo here.

As affordable tyres, for 4 x 13 inch, 4½ x 13 inch & 5½ x 13 inch wheels, become even less readily available over the coming years, Triumph Dolomite & Toledo owners need to be fully aware that substituting 6 x 15 inch, 28 mm offset wheels, originating from MG-F, MG-TF or MG Montego cars, might not be the cheap and simple solution that one would hope, or indeed several other wheels of 3¾ inch (i.e. 95•25 mm) PCD that are available, as you have personally discovered.

Unless something better comes to light, I believe the sets of five 5½ x 15 inch, 31 mm offset wheels, originating from the MG Maestro, probably offer the most practical and cost-effective solution, with the fewest complications, although I acknowledge the desirability, if not necessity, for substitute wheel-fixing studs & associated wheel-nuts. These wheels come from a car which went out of production about 30 years ago, so they are likely to become rarer as the years go by, which is why I took steps to have more than one spare.

Quote:
The set of 4 good condition 6 spoke MGF rims with 4 usable tyres were £125 plus collection expenses (about £25 in fuel) so a single wheel with a good tyre at £40 is not too bad. By contrast, the first set of 4 MGF 5 spoke wheels I bought for the Carledo were only £65 with 3 usable tyres. These were also much more local, only 12 miles from home. But that was circa 2008. The presence or absence of good tyres, even if not the desired size, can affect the price by as much as 50%

My first pair of 5½ x 15 inch MG Maestro wheels with 185/55 R15 tyres (one virtually new!) cost just £10•50 on E-bay, plus under £15 UPS door-to-door courier fees from Surrey, which is less than it would have cost me in petrol, even at circa 40 mpg. On the grounds that most people probably prefer to buy just single sets of one, four (why!?!) or five wheels, I hoped to find some further partial sets of two or three wheels at similarly low prices, but none were listed on E-bay or Gumtree over the following year, and no sets of four or five wheels were listed either, but there were several sets of five 6 x 15 inch MG Montego wheels, or sets of four 6 x 15 inch MG-F & MG-TF wheels.

My set of five 5½ x 15 inch MG Maestro wheels without tyres cost £90, plus under £30 UPS door-to-door courier fees from Yorkshire. A return trip from Essex to Yorkshire by car, would have cost considerably more than £30! Unless wheels come with part-worn tyres in reasonable condition, of a size that one wants [there are legal restrictions on the resale of part-worn tyres - The Motor Vehicle Tyres (Safety) Regulations 1994 - which need to be checked and certified], there is potentially a financial penalty regarding courier fees, pertaining to package dimensions and/or weight.

https://www.partworn-tyres.co.uk/?qards_page=the-law

Unless one has personal access to tyre fitting / removal equipment, removing tyres from wheels prior to selling the wheels costs a significant sum of money and no one wants to give away tyres for nothing with the wheels, unless the tyres are in unserviceable unsalable condition. If one is unable to resell part-used tyres that have been removed, then there is a financial cost associated with disposing of them.
Quote:
On touring kit parts, I admit i'm remiss in not carrying rad hoses, though the car uses cut down standard Omega hoses, i've not got around to buying spare ones yet. most of the other hosework is done in 1/2" or 5/8" straight hose some of which I carry.

Most of the ignition parts on your list, the Omega motor doesn't have, no points, condenser, distributor cap, rotor arm, coil or HT leads. The plugs in the engine are new Platinum tipped ones and it has an all in one coil pack arrangement which I WILL get a spare for eventually, but they are relatively bullet proof (they are also over £100 each new!) I carry a spare crank sensor and fuel pump and relay. Along with bulbs and fuses that any sensible person carries anyway.

The Omega water pump is driven by the timing belt. The belt, pump, tensioner and 3 jockey pulleys were all replaced during the build (why wouldn't you?) with good quality Gates parts which should now be good for another 75k miles.

There would be no useful purpose in carrying spare parts that were not pertinent to the vehicle involved! You might be surprised at how few people carry spare light bulbs & fuses, whether normally sensible or otherwise; despite the fact that fuses are small & cheap, and light-bulbs are fundamentally a consumable item, which require periodic replacement! Based upon past experience, I would be inclined to first test the functionality of all spares, before incorporating them into the touring spares-kit!

I’m not enthusiastic about textile-reinforced rubber camshaft-timing belts; preferring direct gear-operated camshafts or chain-driven camshafts.

Quote:
How far could I get without the fanbelt? I reckon over 100 miles night and 150+ in daylight. This based on a failure I had years ago with my GT6 alternator overcharging and almost melting the battery near Oxford during a weekend trip from home in Shropshire to Maidenhead Berkshire. I had to get to Maidenhead about dusk and couldn't lose the fanbelt for the same reason it would stop you so had to unplug the alternator. I got a bump start and made it in to Maidenhead charged the battery at my friends place and made it 100+ miles home in the dark on the Sunday night (just!, The electric fuel pump was almost stopped and the lights were little better than glow worms, but I got home!)

I presume your Triumph GT6 alternator’s voltage-regulator had failed to limit the supply voltage to less than circa 14½~15 volts, for which the ignition warning-light would have given no warning, which is one reason why I regard having a voltmeter and/or ammeter as essential instrumentation; both of which are part of the instrumentation packages for both the 1974 Triumph Toledo 1300 “HL Special” and the 1973 VW “1600” Type 2 motor-caravan. The voltmeter would have immediately indicated that the voltage-regulator was faulty and the ammeter, if connected between the alternator and the battery, would have indicated that the battery was being overcharged.

Quote:
There must be something about Sweden and camper van charging systems! On a camping trip on the Baltic coast of Sweden in 1973, I had the alternator fail on our brand new (Rented) Bedford CF camper. To my eternal surprise there was a Lucas agent in the tiny coastal town of Vastervik where we camped after the failure, who managed to repair it for a very sensible cost. He spoke perfect English too!

I recall you mentioning several months ago, your experiences with the Bedford CF campervan’s Lucas alternator. At least Västervick has some interesting sightseeing on offer whilst awaiting repairs to be completed; including the church with three altars and the fishermen’s cottages museum. I briefly drove two Bedford CF vehicles (a pickup and a panel van) during the mid-1970s and mid-1980s, both of which had extremely heavy clutches which I didn’t like. I have also driven various other van, campervan & minibus types which I much preferred, including Ford, Leyland, Volkswagen, Toyota & Nissan.

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Wed Jun 15, 2022 9:48 pm 
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TDC Shropshire Area Organiser

Joined: Sun Aug 21, 2011 5:12 pm
Posts: 7013
Location: Highley, Shropshire
RBRR is Club Triumph's bi-ennial, (is that right, every other year?) Round Britain Reliability Run. It is run in early October, so close to the equinox. Teams of 2 or 3 drivers set out in their Triumphs from Knebworth Herts at 6pm on Friday night and drive, more or less up the east coast to John o' Groats where they have breakfast around 7am Saturday. They then proceed down a more westerly route taking in parts of Wales before arriving in Lands End around 7am on the Sunday morning. After another hearty breakfast they then return to Knebworth for the finish, hopefully around 6pm on the Sunday night. There are checkpoints all round the route to keep you honest and there is a 2 hour window to check in at each one. The route is timed to meet an overall average speed of only 40mph so even the smallest and least powerful Triumphs have a chance (one year, some hardy soul competed and completed in a 948cc Standard Atlas VAN!) When I completed in a friend's Dolomite Sprint in 2018, we covered 2166 miles in 49hrs and 1 minute between start and finish.

It's a fearsome challenge for both the entrants and their 40+ year old machinery. Around 140 cars usually start, usually over 100 will complete the course without going over time. It's purely a test of reliability and not competitive. There is no prize for coming first. All you get is a small trophy for completing the event and the satisfaction of knowing that you and your car have done what most moderns and their pilots would baulk at. That and the money we raise for charity whilst doing it, which, in 2021 (2020 run was cancelled of course) exceeded £100,000 for the first time ever!

I'm sorry for using an unexplained acronym, I had thought that everyone on this forum would be aware of the RBRR. It's probably the most gruelling event you can do in a classic car and anyone who has done it (Many of us on here HAVE, some many times) is justifiably proud!

Steve

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted: Sat Jun 18, 2022 6:19 pm 
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Future Club member hopefully!

Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
The Consequences of Car-Manufacturing Variability & Tyre Section-Width Variability

Quote:
So far, I have had extremely limited personal observational experience, of variation in installed tyre section-widths, associated with either installation on different wheel-widths, or production variation in tyres of different brands, having the same nominal tyre size. I had read many years ago, that one might expect significant variation between different tyre brands, and that this was something of which to be wary when retro-fitting wider wheels & tyres to one’s car!

It would be interesting to have a census of Triumph owners, to gain a more in-depth perspective of this variation, as it applies to the various tyre sizes and manufacturers’ brands, that have been fitted to the different sizes of steel or alloy wheels (e.g. 4 x 13 inch, 4½ x 13 inch, 5 x 13 inch, 5½ x 13 inch, 5½ x 14 inch, 5½ x 15 inch & 6 x 15 inch, plus possibly some others) that have been used.

I expect there to be noticeable variation in installed section-width of the same sized tyre, of different manufacturers’ brands, on the same sized wheel.

I expect there to be noticeable variation in installed section-width of the same sized tyre, of the same manufacturer’s brand, on wheels of different sizes.

To measure the installed section-width of the tyres, one simply needs to lay the wheels with tyres installed, on a flat horizontal surface (i.e. level floor, table or workbench), place a straight-edge over the wheel-centre, across the tyre’s side walls on opposite sides, and measure down from the bottom of the straight-edge to the flat surface using a cm & mm tape measure or ruler, at both ends of the straight-edge. Repeat the process at least once; preferably with the straight-edge positioned at right-angles to the original position. Record the average measurement and the degree of variation in measurements.
Quote:
Although the 185/55 R15 tyres that came on my first set of two MG 2000 Maestro 5½J x 15 inch wheels have the same nominal section-width (i.e. 185 mm) as the 185/70 R13 tyres on my Triumph Dolomite Sprint 5½J x 13 inch wheels, the actual installed tyre section-widths (as measured by me using a tape measure in conjunction with a builder’s long spirit level as a straight edge) proved to be noticeably different!

Measuring the section-widths of one of the Firestone S211, 185/70 R13 85T tyres (made in France & South Africa) on the Dolomite Sprint wheels, plus the Michelin MXV2, 185/55 R15 81V tyre (made in West Germany) and Cheng Shin Maxxis MA-551, 185/55 R15 82V tyre (made in PRC – Peoples’ Republic of China; aka Taiwan or Formosa), on the MG Maestro wheels, produced the following results:

Firestone S211, 185/70 R13 – Installed tyre section-width = 189¼ ± ¼ mm

Michelin MXV2, 185/55 R15 – Installed tyre section-width = 189¾ ± ¼ mm

Cheng Shin Maxxis MA-551 185/55 R15 – Installed tyre section-width = 193¼ ± ¼ mm
Quote:
I'm quite sure the arches WOULD have rubbed on the 185/55 shod MGF 15s if I hadn't already partially relieved them in an attempt to clear the JBW 14's. This seems to be a car-by-car thing, I know of some people who've had this particular combo clear without modification, others don't! The Carledo only barely failed to clear 205/50s. The subtle difference in design between the long and short tailed car's rear arches does favour (oddly) the Toledo here.

Although variability in individual cars, attributable to large manufacturing tolerances in the car-manufacturing processes during the 1970s, will probably be a contributory factor, I strongly suspect that the variation in actual installed tyre section-widths [i.e. 185 mm ± tolerance of 5 mm or more!) of different tyre brands, would be a major and possibly greater contributory factor, to the presence or lack of interference and/or tyre-rubbing problems in the rear wheel arches of the Triumph Dolomite & Toledo models, when MG-F or MG-TF 6 x15 inch alloy wheels of 28 mm wheel-offset & 185/55 R15 tyres are installed.

Installed on the MG 2000 Maestro 5½J x 15 inch alloy wheels, the Michelin MXV2 and Cheng Shin Maxxis MA-551 185/55 R15 tyres (of 185 mm nominal section-width, defined for 6 inch wide wheels), had actual installed tyre section widths of 189¾ ± ¼ mm and 193¼ ± ¼ mm respectively. Had those same tyres been installed on the ½-inch wider MG-F or MG-TF 6 x15 inch alloy wheels, then according to the tyre-industry “rule-of-thumb”, I would expect them to have actual installed tyre section-widths of circa 194¾ ± ¼ mm and 198¼ ± ¼ mm respectively; both of which are very much larger than 185 mm!

This is why am interested to learn how much variation is observed in actual installed tyre section-widths, of different brands of 185/55 R15 tyres, on these readily-available, second-hand, MG-F or MG-TF 6 x15 inch alloy wheels! Such information could be critical to owners contemplating the use of said wheels.

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Sat Jun 18, 2022 6:32 pm 
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Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
The Unsuitability of Many 4 x 95•25 mm PCD Wheels for Triumph Dolomites & Toledos!

Quote:
When building the Dolomega, I came upon a cheap set of new fake Minilites. They were being sold as for TR7 so I bought them knowing that stock TR7 wheels will clear the Dolomites rear arches.

It's all about ET (or offset as its sometimes known) Now the Sprint's standard ET is a very high 35 for a car of that vintage and along with the 4x95.25 PCD, limits wheel choice considerably.

The fake minilites made by John Brown Wheels and sold almost everywhere, are not AVAILABLE (when you actually SPECIFY) with an ET higher than 22 which means that the wheels I bought as "TR7", whilst you might be able to make them FIT a TR7, are not TR7 SPEC cos the TR7 ET, AFAIK is 27 (could be higher) and those 5mm make all the difference on a Dolomite!

Moreover, I have not, so far, been able to find ANY aftermarket wheels available to buy at ANY price in 5.5 or 6 x 14" or 15" diameter and using the 95.25 PCD with an ET above 25. Bizzarrely, the best I could find is the MGF 6x15 in several different styles which I have recently discovered have an ET of 28, 6 whole mm better than my fake Minilites! I've been using these on the Carledo for 11 years! I don't really want to use 15s on this car as they necessitate 50 profile tyres which are not as compliant.

As has already been said and reiterated several times in this topic thread and others, the wheel widths & tyre section-widths and wheel-offset dimensions, are critical to whether any given wheel & tyre combination, can be used on a Triumph Dolomite & Toledo, without incurring interference problems with the wheel arches and/or suspension components, especially at the rear.

What often isn’t mentioned, is the dimension described as centre-bore diameter, which if too small will prevent a wheel being fitted on the wheel-hub, and which if too large, results in all of the vehicle’s weight being supported solely by the wheel-fixing screw-studs & wheel-nuts, instead of sharing it with the wheel-hub centre.

For my own interest, I examined the available wheels of 13 inches and greater diameter (i.e. 13, 14 & 15 inches diameter), with a 4 x 3¾ inches (i.e. 4 x 95•25 mm) PCD – pitch circle diameter that are listed on John Brown Wheels’ Internet website. Not one of the wheels listed there could be considered particularly suitable for Triumph Dolomites & Toledos, and some might be considered grossly if not dangerously unsuitable!

John Brown Wheels, Unit 1, Cornwood Farm, Napton Road, Stockton, Warwickshire, CV47 8HU
Tel. +44 (0) 1926 817 444
E-mail: sales@johnbrownwheels.com
Website: https://www.johnbrownwheels.com

On my 1974 Triumph Toledo 1300, from 1975 until mid-1996, I had a set of 5½ x 13 inch Cosmic alloy wheels, having a 21 mm wheel-offset and a circa 56~57 mm centre-bore diameter I believe. Initially, from 1975 until mid-1987, these were shod with 175 SR 13 (i.e. re-labelled in later years as 175/80 R13) tyres, which experienced no interference problems, but in mid-1987, after 185/70 R13 tyres were substituted, the tyres rubbed against the rear wheel arches when carrying rear-seat passengers and/or heavy luggage in the boot. This rubbing ceased to occur, when the Cosmic alloy wheels were exchanged for 5½ x 13 inch Dolomite Sprint alloy wheels with a 35 mm wheel-offset and the existing 185/70 R13 tyres swopped over.

I am aware that the 5½ x 13 inch Dolomite Sprint alloy wheels have a 35 mm wheel-offset and a circa 56~57 mm centre-bore diameter. My substitute 5½ x 15 inch MG 2000 Maestro alloy wheels have a slightly smaller 31 mm wheel-offset and a circa 56~57 mm centre-bore diameter; which to date is the closest match and most suitable substitute wheel, that I have so far managed to identify.

In contrast, 25 mm is the largest wheel-offset of any of the John Brown Wheels with a 4 x 3¾ inches (i.e. 4 x 95•25 mm) PCD – pitch circle diameter and all the alloy wheels are said to have a 67•1 mm, centre-bore diameter which would require the use of a spigot ring (aka hub-centric ring) of some description. I would feel rather uncomfortable relying solely on just four x four relatively puny 3/8” UNF wheel-fixing studs to support the weight of a fully-laden Triumph Toledo (circa 1¼ tonnes) or Triumph Dolomite on their own.

https://www.wheel-size.com/articles/hub-centric-rings/

Strangely, the “Smoothie” steel wheel, is said to have a 157 mm centre-bore diameter, which seems inordinately large! Given that it would be impossible to have a 157 mm centre-bore diameter exceeding the 95•25 mm PCD, this must be a mistake! I wonder whether the centre-bore diameter is actually 57 mm!?!

https://www.johnbrownwheels.com/wheels/

13 Inch Diameter Steel & Alloy Wheels

https://www.johnbrownwheels.com/wheels/ ... fitment=85

5½ x 13 inch – “Minilite” alloy | 25 mm offset | 67•1 mm centre-bore | 5•40 kg weight | £80•35 unit price

https://www.johnbrownwheels.com/product ... -5513ML495

5 x 13 inch – “Minilite” alloy | 20 mm offset | 67•1 mm centre-bore | 5•40 kg weight | £78•05 unit price

https://www.johnbrownwheels.com/product ... -5013ML495

5½ x 13 inch – “Smoothie” steel | 20 mm offset | 157 mm !?! centre-bore | 7•00 kg weight | £82•45 unit price

https://www.johnbrownwheels.com/product ... 5513SMO495

5½ x 13 inch – “D1” alloy | 16 mm offset | 67•1 mm centre-bore | 5•00 kg weight | £80•35 unit price

https://www.johnbrownwheels.com/product ... -5513D1495

6 x 13 inch – “Minilite” alloy | 16 mm offset | 67•1 mm centre-bore | 5•50 kg weight | £83•78 unit price

https://www.johnbrownwheels.com/product ... -6013ML495

6 x 13 inch – “Rallye Special” alloy | 16 mm offset | 67•1 mm centre-bore | 5•60 kg weight | £83•78 unit price

https://www.johnbrownwheels.com/product ... -6013AC495

6 x 13 inch – “Revolite” alloy | 16 mm offset | 67•1 mm centre-bore | 4•70 kg weight | £83•78 unit price

https://www.johnbrownwheels.com/product ... -6013RL495

7 x 13 inch – “Superlite” alloy | negative -7 mm offset | 67•1 mm centre-bore | 6•50 kg weight | £95•28 unit price

https://www.johnbrownwheels.com/product ... 13SUP495-7

14 Inch Diameter Alloy Wheels

https://www.johnbrownwheels.com/wheels/ ... fitment=85

5½ x 14 inch – “Minilite” alloy | 22 mm offset | 67•1 mm centre-bore | 5•80 kg weight | £91•82 unit price

https://www.johnbrownwheels.com/product ... -5514ML495

6 x 14 inch – “Minilite” alloy | 22 mm offset | 67•1 mm centre-bore | 6•20 kg weight | £102•20 unit price

https://www.johnbrownwheels.com/product ... -6014ML495

15 Inch Diameter Alloy Wheels

https://www.johnbrownwheels.com/wheels/ ... fitment=85

5½ x 15 inch – “Minilite” alloy | 15 mm offset | 67•1 mm centre-bore | 6•40 kg weight | £111•91 unit price

https://www.johnbrownwheels.com/product ... -5515ML495

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


Last edited by naskeet on Fri Jun 24, 2022 6:26 pm, edited 3 times in total.

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PostPosted: Mon Jun 20, 2022 6:19 pm 
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Posts: 535
Location: South Benfleet, Essex
Quote:
RBRR is Club Triumph's bi-ennial, (is that right, every other year?) Round Britain Reliability Run.

You are correct in your belief that biennial means recurring every two years; not to be confused with biannual which means occurring twice per year. I had come across sporadic references to the RBRR on the forum, the contexts of which hinted at it being some sort of car-show, motoring or motor-rally event.

https://www.clubtriumph.co.uk/rbrr/intro/

Quote:
It is run in early October, so close to the equinox. Teams of 2 or 3 drivers set out in their Triumphs from Knebworth Herts at 6pm on Friday night and drive, more or less up the east coast to John o' Groats where they have breakfast around 7am Saturday. They then proceed down a more westerly route taking in parts of Wales before arriving in Lands End around 7am on the Sunday morning. After another hearty breakfast they then return to Knebworth for the finish, hopefully around 6pm on the Sunday night.

There are checkpoints all around the route to keep you honest and there is a 2 hour window to check in at each one. The route is timed to meet an overall average speed of only 40 mph so even the smallest and least powerful Triumphs have a chance (one year, some hardy soul competed and completed in a 948cc Standard Atlas VAN!) When I completed in a friend's Dolomite Sprint in 2018, we covered 2166 miles in 49hrs and 1 minute between start and finish.

It's a fearsome challenge for both the entrants and their 40+ year old machinery. Around 140 cars usually start, usually over 100 will complete the course without going over time. It's purely a test of reliability and not competitive. There is no prize for coming first. All you get is a small trophy for completing the event and the satisfaction of knowing that you and your car have done what most moderns and their pilots would baulk at.

I surmised that the first two letters RB might possibly stand for Round Britain, but I had no notion of what the last two letters RR might denote! To my way of thinking, the term Round Britain implies the use of coastal roads wherever possible, of which few would facilitate high speeds; involving little if any use of dual-carriageways or motorways!

To maintain an average speed of 40 mph or more, would probably require one to constantly drive at close to (but not exceeding!) the 70 mph maximum speed limit on all available sections of motorway and dual-carriageway, of which there are precious few in certain areas of the British mainland.

On the narrow, winding roads of the Scottish Highlands, plus west Wales, and various parts of Somerset, Devon & Cornwall, it would be challenging enough to safely maintain an average speed of as much as 35 mph; something I just about managed to do under very light traffic conditions, driving 80 miles cross-country in 2¼ hours, late on Sunday evenings, from Canvey Island to Cranfield, during the early-1980s.

Board index » The Triumph Dolomite Club » Dolomite-related [Start here!] » 40+ Years With A 1974 Triumph Toledo 1300 “HL Special”

viewtopic.php?f=4&t=29933&start=15#p316411

Unless there has been a major new-road building programme over the past 40 years, roads in Scotland north of the Central Lowlands (encompassing Edinburgh, Glasgow, Stirling, Perth & Dundee etc), tend to be narrow and winding, with little opportunity for overtaking slow-moving traffic, although that’s likely to be less of a problem during the wee, small hours of the night. With the sad demise of “cats’ eyes” on rural roads in recent decades, night-driving on unlit rural roads has become more challenging (unless one has a FLIR – Forward Looking Infra-Red vision system); requiring good headlights and auxiliary driving lights (like my early-1980s vintage, 7 inch Lucas 20/20 homo-focal rally lamps) to see well into the distance, before dipping for oncoming traffic.

One could drive up the eastern side of the country via the A1 & A1(M) [on which it is possible to maintain high average speeds] from Junction 7 at Stevenage near London, all the way up to Edinburgh, but this only follows a small proportion of the eastern coast, from north of South Shields & Newcastle-upon-Tyne to Edinburgh, but even so there are alternative routes which more closely follow the coast. The most direct easterly route from Edinburgh, would take one on the M90 to Perth, followed by the shortcut along the A9 to Inverness via Newtonmore and then continuing on the A9 to Wick; bypassing the much longer eastern coastal route, via Dundee, Arbroath, Montrose, Stonehaven, Aberdeen, Peterhead & Fraserburgh to Inverness.

To reasonably follow an eastern coastal route, one might start by following a route from Knebworth via the back-roads to Standon on the western end of the A120, then following the A120, A12, A45 & A12 via Bishops Stortford, Braintree, Colchester, Ipswich, Lowestoft & Great Yarmouth, before branching off onto the B1159 & A149 along the Norfolk coast to Kings Lynn. Then following the A17 around the Wash and branching off near Sutterton to Boston on the A16, followed by the A52 via Skegness & Mablethorpe, before following the A1031 to Cleethorpes. One might continue along the A180, A1077, A15 & A83 via Kingston-upon-Hull, followed by Bridlington, Scarborough, Whitby, Redcar, Middlesborough, Hartlepool, Seaham, Sunderland & South Shields.

Travelling onward from John o Groats along the northern & western Scottish coastal roads and western Welsh coastal roads, would be even more challenging and time consuming!

Quote:
I'm sorry for using an unexplained acronym, I had thought that everyone on this forum would be aware of the RBRR. It's probably the most gruelling event you can do in a classic car and anyone who has done it (Many of us on here HAVE, some many times) is justifiably proud!

My past occupations as a professional scientist, technologist, engineer & teacher, has taught me to avoid the use of abbreviations and/or acronyms where possible, but if circumstances demand it, to define their meaning at their first use in any given item of literature or communication, and sometimes to also include all such definitions in a separate glossary of terms in the appendices.

Back in the mid-1950s to mid-1960s, the road journeys from south east England to north-eastern Scotland (my home was in Dundee) were even more gruelling, not least because many cars had 6V electrical systems (including my father’s late-1940s vintage Morris 8 Series E, 1964 VW 1200 Beetle & 1968 Daf 44), with low-power, low-intensity, glass-envelope, incandescent headlamp bulbs (usefully aided by “cats’ eyes” road studs), had no heating & demisting systems, and could barely sustain more than about 50~55 mph as a maximum. Besides that, there were NO motorways and neither the Forth nor Tay road-bridges then existed.

https://en.wikipedia.org/wiki/Morris_Ei ... t_Series_E

https://en.wikipedia.org/wiki/DAF_44

The standard route from London, was to take the A1 Great North Road as far as Scotch Corner, then turn west on the A66 to Penrith and turn north to Carlisle and Glasgow, followed by Stirling, Perth & Dundee. If there had been a road-bridge or reliable, frequent car-ferry crossing of the Firth of Forth, we could have followed the A1 all the way to Edinburgh and driven through Fife, followed by one of the car-ferries (Abercraig & Scotscraig) across the Firth of Tay directly to Dundee.

https://en.wikipedia.org/wiki/Tay_Road_ ... ry_service

https://queensferrypassage.co.uk

https://en.wikipedia.org/wiki/Forth_Road_Bridge

https://web.archive.org/web/20100531175 ... erries.htm

Strangely, sometime after construction of the Tay road-bridge was completed (I witnessed the first few years of progress), I saw the Abercraig in Valetta harbour, Malta, during a holiday there in 1967; learning many years later that the Scotscraig was also there! I suspect the Abercraig & Scotscraig were later redeployed on the ferry crossings from Malta to Gozo & Comino.

To drive almost continuously day & night for circa 48 hours, even in relays of three people, is not something I would wish to contemplate, and not something I would recommend, except in an exceptional dire emergency!

On the few occasions that I have slept upright in a seat (usually an aircraft seat), I typically woke up with a headache! On long night flights, where possible, I would stretch out across three seats with the arm-rests raised, or even sleep on the floor away from the aisle; which is what I did between Johannesburg and London.

As a small boy, of less than 9½ years old, I probably slept on the back seat of the Morris 8 Series E or VW 1200 Beetle, during our more than 400 mile journeys between Dundee and London, but that would have been lying down. At the age of about 12½ years, I slept stretched out on one of the longitudinal side-facing bench seats of a long-wheelbase, Series 2 Landrover, on the long day & night journey from one of the French channel ports to the Spanish Mediterranean port, on our way to Morocco in 1968.

However, at my tender age, I doubt whether I could sleep these days, either sitting up or laying down, on the rear bench seat of a Triumph Toledo or Dolomite, so I wouldn’t be fit to drive under such circumstances! I also doubt whether I know anyone, that I would trust to drive my Triumph Toledo under normal circumstances, yet alone on a road rally against the clock!

It’s been almost exactly 40 years since I last crossed the Scottish border in either a car or motor-caravan, although I did travel twice in November 1994 and April 1998, from London to Aberdeen and Glasgow (for East Kilbride) respectively, by Intercity 125 over-night sleeper trains, for unsuccessful job interviews at Robert Gordon University, Department of Architecture and the Building Research Establishment [Scottish Laboratory]; being treated to an unintentional tour on foot of the train maintenance depot (i.e. West Coast Polmadie Depot) south of Glasgow, but that’s another story in my saga of life’s experiences.

https://en.wikipedia.org/wiki/Polmadie_TRSMD

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


Last edited by naskeet on Sun Jun 26, 2022 4:59 pm, edited 5 times in total.

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PostPosted: Tue Jun 21, 2022 12:13 am 
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Location: Highley, Shropshire
It would, for the sake of exactness, if nothing else, be nice to use coastal roads wherever possible for the RBRR. However I read somwhere that Britain has over 4000 miles of coastline which would more than double the current running distance and the roads would be far less optimal for maintaining a decent average speed. I suspect that, were one to attempt such a feat, elapsed time would be nearer 5 days than the current 48 hours. While most entrants seem to be able to rough it and sleep in the moving car for 2 days, I doubt many would care to extend that to 5! A lot of my colleagues in this endeavour, including one of my co drivers, are over 70 and I will be 69 when my next chance rolls around in 2023. None of us are Superman but we manage. Very few drop out from exhaustion, most DNFs (Did Not Finish) are from mechanical failure that can't be repaired in a suitable timeframe.

Maybe we are all mad! You get to the end and you are literally wiped out and running on adrenaline, all you want to do is fall into a bed and sleep for a week. Somehow, the next morning, you are laying plans for the next one, it's addictive!

As it is, we miss out all of the southeast, including London and the Welsh section is more of a trip through the Welsh Marches sometimes in Wales, sometimes in England. Not much of a loss as, once again, it is undertaken in the middle of the night! But, whilst "Round a large part of Britain" may be more exact, it doesn't have the same ring to it!

My biggest problem was sleeping in the car in daylight as I did a lot of the night sections behind the wheel (including that seemingly endless 100+ miles of A9 from Inverness to Wick which I drove in the small hours of Saturday morning, an almost ruler straight road, nothing to see but trees to the left and dark ocean invisible to the right and 60mph average speed cameras to comply with on the entire stretch) An eye mask and earplugs, along with a couple of pillows make the back seat habitable if one has one's feet in one footwell and body on the other side. Though next time, i'm taking a sleeping bag, heat from the heater doesn't get to the rear seat area too well!

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted: Fri Jun 24, 2022 5:43 pm 
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Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
Quote:
My biggest problem was sleeping in the car in daylight as I did a lot of the night sections behind the wheel (including that seemingly endless 100+ miles of A9 from Inverness to Wick which I drove in the small hours of Saturday morning, an almost ruler straight road, nothing to see but trees to the left and dark ocean invisible to the right and 60mph average speed cameras to comply with on the entire stretch) An eye mask and earplugs, along with a couple of pillows make the back seat habitable if one has one's feet in one footwell and body on the other side. Though next time, i'm taking a sleeping bag, heat from the heater doesn't get to the rear seat area too well!

Examining my 1988 AA Road Atlas, the A9 route from Inverness to Wick, the distance appears to be closer to 75 miles, rather than 100+ miles, but two route-planner websites state that it is actually 103 miles. :oops:

https://ukdistance.com/route/inverness/wick

https://www.viamichelin.co.uk/web/Route ... ed_Kingdom

If instead of using Triumph cars for the RBRR, 1968~79 VW Type 2 (have the advantage of fully-independent front & rear suspension, with low unsprung weight) campervans had been used, you could have had a more comfortable sleep in the back with curtains closed, on a properly upholstered, full-size double bed; above the warm rear-engine compartment! I have a Blacks & Edgington “Norseland” down-filled sleeping bag with supplementary hood for cold-weather use, which was bought for our 1971 summer camping holiday in Iceland, with the adventure-holiday company Minitrek.

https://www.blacks.co.uk/activities/ten ... ping-bags/

https://www.blacks.co.uk/activities/ten ... ping-bags/

Triumph Toledos & Dolomites, as well as 1968~79 VW Type 2s, certainly need improved rear-passenger heating provision!

Board index » The Triumph Dolomite Club » Dolomite-related [Start here!] » Improving Heating, Ventilation, Demisting & Defrosting

https://forum.triumphdolomite.co.uk/vie ... 21#p339121

The introductory page to Club-Triumph’s RBBR, mentions that the 2021 RBBR nominated charity was the MNDA - Motor Neurone Disease Association.

https://www.clubtriumph.co.uk/rbrr/intro/

Sadly, my father died from MND – motor-neurone disease at the age of 82¼, in early-September 2011; having received final confirmation of diagnosis in August 2010, but had been underdoing sporadic neurological investigation for a few years prior to this. My mother and I were subjected by my father (a retired GP), to a rather distressing, week-by-week running commentary about muscle-function deterioration, as the disease progressed. The cousin of my maternal uncle (i.e. my mother’s sister’s husband) also died from MND several decades ago, but at a much younger age in his early-40s. Typically, about 50% of MND suffers die within 1 year of diagnosis and most of the remainder within the following year.

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


Last edited by naskeet on Fri Jun 24, 2022 7:28 pm, edited 3 times in total.

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PostPosted: Fri Jun 24, 2022 5:50 pm 
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Joined: Tue May 06, 2014 4:38 pm
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Location: South Benfleet, Essex
Revisiting Wheel Centre-Bore & Spigot Rings
Quote:
I am aware that the 5½ x 13 inch Dolomite Sprint alloy wheels have a 35 mm wheel-offset and a circa 56~57 mm centre-bore diameter. My substitute 5½ x 15 inch MG 2000 Maestro alloy wheels have a slightly smaller 31 mm wheel-offset and a circa 56~57 mm centre-bore diameter; which to date is the closest match and most suitable substitute wheel, that I have so far managed to identify.

In contrast, 25 mm is the largest wheel-offset of any of the John Brown Wheels with a 4 x 3¾ inches (i.e. 4 x 95•25 mm) PCD – pitch circle diameter and all the alloy wheels are said to have a 67•1 mm, centre-bore diameter which would require the use of a spigot ring (aka hub-centric ring) of some description. I would feel rather uncomfortable relying solely on just four x four relatively puny 3/8” UNF wheel-fixing studs to support the weight of a fully-laden Triumph Toledo (circa 1¼ tonnes) or Triumph Dolomite on their own.

https://www.performancealloys.com/acces ... igot-rings

I more closely examined the selection of spigot rings listed on the associated eight pages of Performance Alloys’ Internet website as follows, to try and identify which if any of the spigot rings available, might be suitable for use on the Triumph Toledo & Dolomite wheel-hubs equipped with the John Brown Wheels’ “Minilite” style and other wheels, having a 4 x 3¾ inches (i.e. 4 x 95•25 mm) PCD and 67•1 mm, centre-bore diameter. Various car marques were cited, but unsurprisingly there was no mention of Triumph or MG.

https://www.performancealloys.com/

https://www.performancealloys.com/accessories/

https://www.performancealloys.com/acces ... igot-rings

It became apparent that there are three common hub-spigot diameters of circa 56~57 mm, which are 56•1 mm, 56•6 mm & 57•1 mm, so it seemed sensible to make some more-precise measurements of my Triumph Dolomite Sprint and MG 2000 Maestro wheels’ centre-bore diameter.

56•1 mm centre-bore diameter – said to correspond to MINI, Honda & Mitsubishi wheels

Set of 4 Italian Spigot Rings (67.1-56.1) - Fits MINI, Honda, Mitsubishi | £7•80

https://www.performancealloys.com/4-ita ... -1-polymer

Set of 4 Italian Spigot Rings (67.1-56.1) - Fits MINI, Honda, Mitsubishi | £7•80

https://www.performancealloys.com/4-ita ... -1-polymer


56•6 mm centre-bore diameter – said to correspond to Lotus & Vauxhall wheels

Set of 4 Italian Spigot Rings (67.1-56.6) - Fits Lotus, Vauxhall | £7•80

https://www.performancealloys.com/4-ita ... -6-polymer

Set of 4 Italian Spigot Rings (67.1-56.6) - Fits Lotus, Vauxhall | £7•80

https://www.performancealloys.com/4-ita ... -6-polymer


57•1 mm centre-bore diameter – said to correspond to BMW, Audi & VW wheels

Set of 4 Italian Spigot Rings (67.1-57.1) - Fits BMW, Audi, VW | £7•80

https://www.performancealloys.com/4-ita ... -1-polymer

Set of 4 Italian Spigot Rings (67.1-57.1) - Fits BMW, Audi, VW | £7•80

https://www.performancealloys.com/4-ita ... -1-polymer

Set of 4 TPI Spigot Rings (67.1-57.1) - Fits BMW, Audi, VW | £20•02

https://www.performancealloys.com/set-o ... -67-1-57-1


From my associations with 1971~79 VW Type 2s, I am already acquainted with the 57•1 mm centre-bore diameters of many VW & Audi wheels having the appropriate 5 x 112 mm PCD, that have to bored-out if they are to be used on the VW Type 2, which requires wheels of circa 66•6 mm centre-bore diameter; as found on many Mercedes C-Class & E-Class wheels, of 5 x 112 mm PCD and appropriate wheel-offset, in the range 33~41 mm! Although my father had a succession of two Honda cars between 1977 and 1987, one with Cosmic alloy wheels, I didn’t take much notice of things like wheel specifications in those days, so cannot comment on whether they had 56•1 mm centre-bore diameters or not!

Carefully using my cm & mm tape measure, to ensure that I was measuring a diameter rather than a chord, I obtained a measurement of the Triumph Dolomite Sprint wheels that appeared to be extremely close to 56½ mm, which suggests that these wheels might actually have a 56•6 mm centre-bore diameter, in common with the 2000~2004 Lotus Exige S1 wheels of 4 x 3¾ inches (i.e. 4 x 95•25 mm) PCD and 38 mm wheel-offset. To obtain a more precise measurement, I would require some Vernier calipers!

http://www.wheel-fitment.com/car/Lotus/ ... 2004).html

https://tireswheels.org/lotus-exige-s1-2000-2004/

Inconveniently, the centre-bore of MG 2000 Maestro wheels is chamfered, so I could not measure the centre-bore diameter using my cm & mm tape measure. However, I was able to obtain an indirect measurement using my drawing-set dividers and my cm & mm ruler, that appeared to be extremely close to 57 mm, which suggests that these wheels might actually have a 57•1 mm centre-bore diameter. This is consistent with what the following Internet website links, proclaim about MG Maestro & MG Montego wheels. To obtain a more precise measurement, I would again require some Vernier calipers!

https://www.wheel-size.com/size/mg/maestro/

https://www.wheel-size.com/size/mg/montego/

All three of the following Internet website links, proclaim the 1995~2002 MG-F & 2002~2011 MG-TF wheels, to have a 56•6 mm centre-bore diameter, in common with the Triumph Dolomite Sprint wheels, but in contrast to the MG 2000 Maestro wheels, but it would be useful to have this confirmed by people who actually possess some MG-F or MG-TF wheels and are able to measure this.

https://www.wheel-size.com/size/mg/f/

https://www.wheel-size.com/size/mg/tf/

http://www.mgf.ultimatemg.com/group2/su ... he_mgf.htm

Hence:

56•6 mm centre-bore diameter – appears to apply to Triumph Dolomite Sprint, MG-F & MG-TF wheels

57•1 mm centre-bore diameter – appears to apply to MG Maestro & MG Montego wheels

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


Last edited by naskeet on Fri Jun 24, 2022 9:54 pm, edited 2 times in total.

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PostPosted: Fri Jun 24, 2022 5:54 pm 
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Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
Quote:
Also an impending £220 bill for 4 new 185/60/15 Toyos for the Dolomega and another £110 for 2 more 185/65/15s to even up the Picasso makes a big hole in my pension! even when partially offset by the sale of the John Brown 14" fake minilites, which ought to make a couple of hundred with tyres. They WILL fit TR7, Spitfire, Herald, Vitesse, GT6 and Morris Minor without any problems so there IS a market to tap into. But I have to spend the money before I can make it back!

Your John Brown Wheels’ 14 inch of very similar wheel-offset to that of the set of new 5 x 13 inch reproduction “Minilite” style alloy wheels (20 mm wheel-offset), that Alistair Cox in Wellington, New Zealand, bought for his Triumph Toledo 1500 some time ago, although I don’t know whether he has yet tried them out. Several months ago, in September 2021, I did some further research on this, being concerned that Alistair’s decision to buy these new 5 x 13 inch “Minilite” style wheels might come back to haunt him.

Board index » The Triumph Dolomite Club » Restoration Projects » Triumph Toledo - Wellington New Zealand

https://forum.triumphdolomite.co.uk/vie ... 02#p338602

If he has fitted 175/70 R13 tyres he will probably avoid interference & rubbing problems. However, based upon my own experiences during the early-1990s with 185/70 R13 tyres on 5½ x 13 inch Cosmic alloy wheels having a 21 mm wheel-offset, he might experience some disconcerting over-steer & under-steer characteristics, when negotiating bends under power! It’s my hypothesis that this phenomenon arose, owing to the change in steering-offset (i.e. tyre scrub radius), which will occur if one uses wheels of a different wheel-offset and/or tyres of a different external radius.

When I previously had 175 SR13 (i.e. 175/80 R13) tyres on these Cosmic wheels (21 mm wheel-offset), there was no hint of any disconcerting over-steer & under-steer characteristics, so if Alistair intends to use the 5 x 13 inch reproduction “Minilite” style alloy wheels (20 mm wheel-offset), it might be preferable to use 175/80 R13 tyres instead. Recent investigation of tyre factors in the Wellington area of North Island, New Zealand, has revealed that 175/70 R13, 175/75 R13 and 175/80 R13 tyres are presently available there.

If Alistair really wanted 13 inch wheels, to use with either 175/70 R13 or 185/70 R13 tyres, I felt he would be better off with 5½ x 13 inch Triumph Dolomite Sprint wheels, whose 35 mm wheel-offset would be better suited to his Toledo!

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Fri Jun 24, 2022 6:39 pm 
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Joined: Sun Aug 21, 2011 5:12 pm
Posts: 7013
Location: Highley, Shropshire
I've found out the hard way about another limitation on wheels, or rather tyres, imposed by the car. This time, surprisingly, on the front.

I bought the 4 185/60/15 Toyo Proxes CF2s and nitially fitted only a pair to the naked MGF 6 spokes that had previously held the 205/50s that were so spectacularly useless on the Picasso (the Picasso is now back on 185/65/15s all round and much happier for it!)

This turned out to be a sensible move, as I fitted this new pair of 185/60s to the FRONT of the Dolomega and before I even got off the driveway they started to rub on the front spoiler/valance at a particular point near where the wing meets the valance and where the valance is furthest aft, came into contact with the tyre at a certain (near full) amount of lock only. Fine while driving, but hopeless while manoevering at low speeds!

I've now swapped the 185/60s to the rear and the horrible 185/55 Linglongs to the front and this works satisfactorily. It's also given the car a jaunty nose down rake which I quite like. But I dislike having different sized tyres on the car so I may at some point have to return to 185/55s all round to satisfy my OCD (Obsessive Compulsive Disorder) The NEXT set of tyres will be soon enough for THAT!

In the meantime I now have 2 brand new 185/60/15 tyres with nowhere to fit them, no doubt i'll think of something! (wonder if the Picasso will accept THOSE, it's only a 5% drop in profile rather than the 15% drop that was so unsuccessful!

As far as rear arch contact is concerned the 185/60s seem no worse than the 185/55s did, ie only very light grazing contact under extreme provocation of weight on board and heavy road bumps. I'm hoping the new rear springs and shock absorbers i've bought will negate this entirely, without recourse to more cutting! The back end of the car does seem suspiciously soft, even by my standards.

All i'll say further about that long stretch of A9, is that, at one point not long into it, the satnav advised me that the next thing I would encounter on my chosen route, was a roundabout 99 MILES AWAY! And at that, I was due to take the 2nd (straight on) exit! That's almost AUSTRALIAN!

I can't say how Alastair will get on with his 20mm ET 13s. The fact that they ARE 13s may work just enough in his favour to get him out of trouble. I agree that Sprint rims would be a more suitable choice, but he's faced with an extremely limited supply of these as the only Sprints in NZ are (were) personal imports. I dread to think about the cost of shipping even 4 bare rims to NZ! That and Sprint wheels are an even more hackneyed choice than Minilites.

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted: Fri Jun 24, 2022 7:55 pm 
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MG Maestro / Montego METRIC Wheels

Browsing on British E-bay a few years ago, I came across a pair of some other wheels listed for £90, which were described as being for the MG Montego or Maestro. I suspect that they might have been early offerings, with wheel-rim diameter & width in METRIC units rather than the traditional INCHES, but I cannot discern any useful information from the picture and the vendor did not respond to my questions. To my taste they are not a particularly attractive wheel, but I wonder whether compatible tyres for METRIC-sized wheels are even available these days and if so how the prices compare with those for conventional INCH-sized wheels!?!

MG Maestro or Montego metric-size (?) alloy wheels

Image

Image


Maestro & Montego Owners Club > General Forums > General Maestro & Montego > MG Maestro Alloy wheels tyre size

http://www.maestro.org.uk/forums/showthread.php?t=21137

Reproduced from an OLD magazine article about tyres:

TRX/TDX tyre markings

Because TRX/TDX tyres are fitted to a different type of rim unsuitable for standard-series tyres, two precautions are taken:

• The TRX/TDX wheels are different in diameter to standard rims, the actual diameters being 290, 315, 340, 365, 415 and 450 mm or (roughly) 11•5, 12•5, 13•5, 14•5, 15•5, 16•5 and 17•75 inches
• To emphasise the difference, TRX/TDX tyres are marked with dimensions entirely in millimetres, thus: 190/65 R 390 TRX 89 H

Taking the markings in order, this tyre has a nominal section width of 190 mm, an aspect ratio of 65%, is radial ply, fits on a 390 mm diameter rim, is TRX type and has a load rating of 89 and a speed symbol H. NOTE that TRX tyres can be fitted to a TDX rim but NOT vice versa. All TRX/TDX tyres are tubeless and tubes MUST NOT be fitted.

_________________
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Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Fri Jun 24, 2022 9:18 pm 
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Joined: Sun Aug 21, 2011 5:12 pm
Posts: 7013
Location: Highley, Shropshire
Quote:
MG Maestro / Montego METRIC Wheels

Browsing on British E-bay a few years ago, I came across a pair of some other wheels listed for £90, which were described as being for the MG Montego or Maestro. I suspect that they might have been early offerings, with wheel-rim diameter & width in METRIC units rather than the traditional INCHES, but I cannot discern any useful information from the picture and the vendor did not respond to my questions. To my taste they are not a particularly attractive wheel, but I wonder whether compatible tyres for METRIC-sized wheels are even available these days and if so how the prices compare with those for conventional INCH-sized wheels!?!

MG Maestro or Montego metric-size (?) alloy wheels

Image

Image


Maestro & Montego Owners Club > General Forums > General Maestro & Montego > MG Maestro Alloy wheels tyre size

http://www.maestro.org.uk/forums/showthread.php?t=21137

Reproduced from an OLD magazine article about tyres:

TRX/TDX tyre markings

Because TRX/TDX tyres are fitted to a different type of rim unsuitable for standard-series tyres, two precautions are taken:

• The TRX/TDX wheels are different in diameter to standard rims, the actual diameters being 290, 315, 340, 365, 415 and 450 mm or (roughly) 11•5, 12•5, 13•5, 14•5, 15•5, 16•5 and 17•75 inches
• To emphasise the difference, TRX/TDX tyres are marked with dimensions entirely in millimetres, thus: 190/65 R 390 TRX 89 H

Taking the markings in order, this tyre has a nominal section width of 190 mm, an aspect ratio of 65%, is radial ply, fits on a 390 mm diameter rim, is TRX type and has a load rating of 89 and a speed symbol H. NOTE that TRX tyres can be fitted to a TDX rim but NOT vice versa. All TRX/TDX tyres are tubeless and tubes MUST NOT be fitted.
I had an MG Maestro 2.0 EFi fitted with these wheels (affectionately known as "slabs") way back in the early 2000s. As far as I can remember the car used "normal" sized tyres. Not that THAT means much, it was a 1990 H reg car and therefore one of the last. Twas a quick old thing, but even though it had been cared for carefully by it's 2 previous owners, it was riddled with tinworm. I replaced both sills and fitted a couple of 2nd hand doors and a tailgate to spruce it up a bit and get it legal and moved it on after a fun 6 months or so. I heard recently that it has survived and is now undergoing a near concours restoration!

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted: Sat Jun 25, 2022 5:53 pm 
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On Wednesday, 22nd June 2022, the Facebook “Toledo Triumphs” Group gained a new member by the name of Ben Clare, who seemingly hails from New Plymouth, North Island, New Zealand. In his introductory post, he included a picture of his grey, four-door Triumph Toledo, which appears to be fitted with “Minilite” style alloy wheels, which might be of the same specification as those bought by Alistair Cox. My hope, is that he will provide information about his wheel & tyre combination, revealing what if any problems he might have encountered.

https://en.wikipedia.org/wiki/New_Plymo ... 20migrated.

https://www.facebook.com/groups/3886875 ... 559953832/

https://www.facebook.com/photo?fbid=101 ... 2090862961

Although there might have been relatively few Dolomite Sprints in New Zealand, they might have been more widespread in Australia, which has a much larger population. Being much nearer than Great Britain to New Zealand, shipping costs from Australia would hopefully be much cheaper.

Even so, the relatively modest purchase price of five second-hand Dolomite Sprint wheels from Great Britain plus the shipping cost to New Zealand, might not be very different from the significantly greater purchase price of four or five new reproduction “Minilite” style wheels (about £90 each + 15% GST – Goods & Services Tax) from Palmside in Christchurch, South Island, New Zealand plus the shipping costs to Wellington, North Island, New Zealand.

Size: 13 x 5 PCD 4 Rim depth 21 Offset ET20 with caps and nuts in Silver for Triumph | NZ$181•73 excluding GST

https://palmside.co.nz/collections/whee ... ke-4x95-25

https://palmside.co.nz/collections/13-inch-wheels

https://palmside.co.nz/collections/14-inch-wheels

https://palmside.co.nz/collections/15-inch-wheels

https://www.govt.nz/browse/tax-benefits ... /gst-rate/

https://palmside.co.nz/pages/freight-charges

If one is canny, one might be able to find a shipping agent sending a large consignment of stuff in a standard shipping container, from Australia or Great Britain to New Zealand, who has unused space to include an additional supplementary consignment of modest size & weight, for onward shipping within New Zealand.

Why would you think of Dolomite Sprint wheels as being a “hackneyed” choice (hackneyed => made commonplace or trite by overuse | trite => worn out by constant repetition); especially as the substitution of 6 x 15 inch MG-F & MG-TF is becoming increasingly common!?! After all, they were factory-fitted to all the Triumph Dolomite Sprint cars, so far as I am aware!

One’s choice of wheel style, is all a matter of taste, practicality and cost. It should not matter whether this choice is shunned or enthusiastically adopted by many others, but that will doubtless depend on whether one is inclined to be an individualist or a member of the crowd, which tends towards greater uniformity, as illustrated by the various adolescent groups, such as “teddy-boys”, “mods”, “rockers”, “skin-heads”, “punks” & “goths” etc.

I rather liked the look of my 5½ x 13 inch Cosmic alloy wheels (21 mm wheel-offset), but their wheel-offset and other aspects of their design & construction affecting balance-weight location & attachment, rendered them less than ideal. The disconcerting steering characteristics associated with the later substitution of 185/70 R13 tyres, in place of the “original” 175 SR13 tyres (redesignated as 175/80 R13 | now relatively expensive & difficult to source), was also a consideration.

I also quite like my existing substitute 5½ x 13 inch Dolomite Sprint wheels (35 mm wheel-offset), but the long-term availability and relative cost of appropriate replacement 185/70 R13 or 175/70 R13 tyres, combined with my desire to have a slightly-lower-profile tyre, of larger external circumference [mainly for reason of overall engine gearing] similar to that of my “original” 175 SR13 tyres, dictated the use of 15 inch wheels & 185/65 R15 tyres; a potential combination I had identified back in the early-1980s.

Fortunately for me, I was able to identify through extensive on-line research a few years ago, some suitable modest-cost, second-hand, MG factory-fitted 5½ x 15 inch wheels (31 mm wheel-offset), in a style which I found quite appealing. So long as they serve my needs, I am not concerned whether no-one or everyone chooses to follow suit; merely informing them of my findings and leaving them to make their own choice.

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Sun Jun 26, 2022 5:10 pm 
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Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
Quote:
I've found out the hard way about another limitation on wheels, or rather tyres, imposed by the car. This time, surprisingly, on the front.

I bought the 4 185/60/15 Toyo Proxes CF2s and initially fitted only a pair to the naked MGF 6 spokes that had previously held the 205/50s that were so spectacularly useless on the Picasso (the Picasso is now back on 185/65/15s all round and much happier for it!)

This turned out to be a sensible move, as I fitted this new pair of 185/60s to the FRONT of the Dolomega and before I even got off the driveway they started to rub on the front spoiler/valance at a particular point near where the wing meets the valance and where the valance is furthest aft, came into contact with the tyre at a certain (near full) amount of lock only. Fine while driving, but hopeless while manoevering at low speeds!

I've now swapped the 185/60s to the rear and the horrible 185/55 Linglongs to the front and this works satisfactorily. It's also given the car a jaunty nose down rake which I quite like. But I dislike having different sized tyres on the car so I may at some point have to return to 185/55s all round to satisfy my OCD (Obsessive Compulsive Disorder) The NEXT set of tyres will be soon enough for THAT!

As far as rear arch contact is concerned the 185/60s seem no worse than the 185/55s did, ie only very light grazing contact under extreme provocation of weight on board and heavy road bumps. I'm hoping the new rear springs and shock absorbers i've bought will negate this entirely, without recourse to more cutting! The back end of the car does seem suspiciously soft, even by my standards.

These Triumph Dolomite & Toledo cars seem determined to baulk our attempts to substitute & use, non-standard wheels and/or tyres!

What characteristics or features, prompts you to describe the 185/55 R15 Ling Long tyres as horrible?

Like you, I would NOT have anticipated the problem you have recounted, as a consequence of using the 6 x 15 inch MG-F alloy wheels (28 mm wheel-offset) & 185/60 R15 tyres at the FRONT!

Could this in any way be related to the car’s body ride-height relative to the front wheel-hub centres, associated with the installed front-suspension spring-height?

Have you yet tried out your 5½ x 14 inch MG-F “space-saver” steel wheel & 185/65 R14 tyre, at both the front and rear, to determine whether there might be any interference or rubbing problems with that?

Despite your detailed description, I am experiencing difficulty trying to visualise how this mode of tyre – bodywork interference is possible; especially as my Triumph Toledo has been jacked-up on four axle stands for the past few years with all of the wheels off!?!

Which part of the tyre (e.g. tread or sidewall | inboard, centre or outboard) was making contact?

On close to full right-hand lock (i.e. turning right, with close to full clockwise steering-wheel rotation), was contact being made by the right-hand wheel or the left-hand wheel?

On close to full left-hand lock (i.e. turning left, with close to full anti-clockwise steering-wheel rotation), was contact being made by the left-hand wheel or the right-hand wheel?

To clarify the matter, one needs to identify whether the problem has arisen as a consequence of the 185/60 R15 Toyo Proxes CF2 tyres having a wider installed section-width and/or larger external radius than the 185/55 R15 Ling Long tyres.

In the interests of educating & forewarning the wider Dolomite & Toledo ownership, some pictures might be useful.

A pair of four-post-ramp swivel-plates or wheel-dollies on castors, might be a useful accessory for further investigating and photographing, the areas or points of contact, between the bodywork and the front tyres. This would enable the steering wheel to be slowly turned whilst observing the interaction between the bodywork and tyre; creating an opportunity for a potential U-tube video perhaps!

Before I splash out any money in the future, on a set of five or six tyres, for my Triumph Toledo’s set of seven 5½ x 15 inch, MG 2000 Maestro alloy wheels, I would be well advised to undertake some similar investigations when the opportunity presents, using the two wheels that came with 185/55 R15 tyres; the outcome of which might seriously influence whether I ultimately choose 185/55 R15, 185/60 R15, 185/65 R15, 175/55 R15, 175/60 R15 or 175/65 R15 tyres, all of which would be compatible with 5½ x 15 inch wheels.
Quote:
Keep in mind, that on average, 185/60 R15 tyres will have a circa 5 mm greater installed section-width than 185/55 R15 tyres, that are mounted on the same wheels. Also keep in mind, that the installed section-width of tyres, mounted on wheels of “standard” or “measuring” width, can vary considerably between different tyre manufacturers & brands, so a tyre of 185 mm nominal section-width, might conceivably be 185 ± 5 mm.
Quote:
I expect there to be noticeable variation in installed section-width of the same sized tyre, of different manufacturers’ brands, on the same sized wheel.

I expect there to be noticeable variation in installed section-width of the same sized tyre, of the same manufacturer’s brand, on wheels of different sizes.
Quote:
Although the 185/55 R15 tyres that came on my first set of two MG 2000 Maestro 5½J x 15 inch wheels have the same nominal section-width (i.e. 185 mm) as the 185/70 R13 tyres on my Triumph Dolomite Sprint 5½J x 13 inch wheels, the actual installed tyre section-widths (as measured by me using a tape measure in conjunction with a builder’s long spirit level as a straight edge) proved to be noticeably different!

Measuring the section-widths of one of the Firestone S211, 185/70 R13 85T tyres (made in France & South Africa) on the Dolomite Sprint wheels, plus the Michelin MXV2, 185/55 R15 81V tyre (made in West Germany) and Cheng Shin Maxxis MA-551, 185/55 R15 82V tyre (made in PRC – Peoples’ Republic of China; aka Taiwan or Formosa), on the MG Maestro wheels, produced the following results:

Firestone S211, 185/70 R13 – Installed tyre section-width = 189¼ ± ¼ mm

Michelin MXV2, 185/55 R15 – Installed tyre section-width = 189¾ ± ¼ mm

Cheng Shin Maxxis MA-551 185/55 R15 – Installed tyre section-width = 193¼ ± ¼ mm
Quote:
Although variability in individual cars, attributable to large manufacturing tolerances in the car-manufacturing processes during the 1970s, will probably be a contributory factor, I strongly suspect that the variation in actual installed tyre section-widths [i.e. 185 mm ± tolerance of 5 mm or more!) of different tyre brands, would be a major and possibly greater contributory factor, to the presence or lack of interference and/or tyre-rubbing problems in the rear wheel arches of the Triumph Dolomite & Toledo models, when MG-F or MG-TF 6 x15 inch alloy wheels of 28 mm wheel-offset & 185/55 R15 tyres are installed.

Installed on the MG 2000 Maestro 5½J x 15 inch alloy wheels, the Michelin MXV2 and Cheng Shin Maxxis MA-551 185/55 R15 tyres (of 185 mm nominal section-width, defined for 6 inch wide wheels), had actual installed tyre section widths of 189¾ ± ¼ mm and 193¼ ± ¼ mm respectively.

Had those same tyres been installed on the ½-inch wider MG-F or MG-TF 6 x15 inch alloy wheels, then according to the tyre-industry “rule-of-thumb”, I would expect them to have actual installed tyre section-widths of circa 194¾ ± ¼ mm and 198¼ ± ¼ mm respectively; both of which are very much larger than 185 mm!

One of the major issues with using 6 x 15 inch wheels instead of 5½ x 15 inch wheels, is that if one installed exactly the same tyre on both wheels, the tyre’s installed section-width, is going to be about 5 mm wider when installed on the half-inch wider wheel, giving about 2½ mm less clearance on either side.

https://www.tirerack.com/tires/tiretech/tiretech.jsp

http://www.tirerack.com/tires/tiretech/ ... techid=198

Noting that the “standard measuring wheel widths” of 185/55 R15 tyres and 185/60 R15 tyres, are 5½ inches and 6 inches respectively, one would expect on average (variability associated with different tyre brands & models), that when installed on exactly the same wheel, the 185/60 R15 tyres would have an installed section-width which is about 5 mm wider than that of the 185/55 R15 tyres.

Tyres: 185/55 R15 => Wheels: 15 x 5 minimum | 15 x 6 standard | 15 x 6½ maximum
Tyres: 185/60 R15 => Wheels: 15 x 5 minimum | 15 x 5½ standard | 15 x 6½ maximum
Tyres: 185/65 R15 => Wheels: 15 x 5 minimum | 15 x 5½ standard | 15 x 6½ maximum
Tyres: 185/70 R15 => Wheels: 15 x 4½ minimum | 15 x 5 standard | 15 x 6 maximum

http://www.tyresizecalculator.com/wheel ... rator-list

http://www.tyresizecalculator.com/tyre- ... calculator

http://www.tyresizecalculator.com/tyre- ... calculator

One might not actually observe this precise difference when comparing just two individual tyres (especially if they are of different brands & models), because average difference is relating to statistical trends and the difference between mean values of two different populations. It’s well recognised that on average, men are taller and heavier than women, but from the overall population of interest (e.g. local, regional, national, continental or global), there are probably many possible pairs of randomly chosen individual men and women, where the woman is taller and/or heavier than the man. Beyond that, I would have to refer you to a relatively advanced text on the theory of statistical distributions and statistical inference.

Whilst you still have both the 185/60 R15 Toyo Proxes CF2 and 185/55 R15 Ling Long tyres on nominally “identical” 6 x 15 inch MG-F alloy wheels (28 mm wheel-offset), it might be useful to quantify their dimensions by measuring the tyres’ external circumferences (from which one can infer radius) using a non-stretchy, oversized dress-makers’ tape-measure (or length of wire or mono-filament fishing line etc) and installed section-widths, using the method I have previously described above. I would suggest that you also do the same with your 5½ x 14 inch MG-F “space-saver” steel wheel (unspecified wheel-offset!?!) & 185/65 R14 tyre.

As an alternative to measuring a tyre’s circumference, one could determine its diameter (from which one can also infer radius), by placing the wheel flat on the ground, with the tyre tread against a flat wall. Then place a straight edge against the diagonally opposite section of tyre-tread furthest from the wall, and measure from the straight edge to the wall from either end of the straight edge, in a similar fashion to how the installed section-width is determined.

Keep in mind the tyres’ external radius variation owing to actual tread-depth, associated with the presence or absence of tread-wear; which is likely to emphasize the disparity between the new, unused 185/60 R15 Toyo Proxes CF2 tyres (typically 7~8 mm tread-depth) and the old, part-worn 185/55 R15 Ling Long tyres (more than 1•6 mm tread-depth)!

Comparing a new, unused 185/60 R15 tyre with a completely-worn 185/55 R15 tyre, could result in their tyre external radii differing by as much as circa 15½ mm!

175/65 R14 tyres – predicted external radius = 291•54 mm (0•7 mm less than 185/55 R15)

185/55 R15 tyres – predicted external radius = 292•25 mm

185/70 R13 tyres – predicted external radius = 294•59 mm (2•3 mm more than 185/55 R15)

185/65 R14 tyres – predicted external radius = 298•04 mm (5•8 mm more than 185/55 R15)

185/60 R15 tyres – predicted external radius = 301•5 mm (9•25 mm more than 185/55 R15)

175/80 R13 tyres – predicted external radius = 305•09 mm (12•8 mm more than 185/55 R15)

175/82 R13 tyres – predicted external radius = 308•59 mm (16•3 mm more than 185/55 R15)

175/83 R13 tyres – predicted external radius = 310•34 mm (18•1 mm more than 185/55 R15)

185/65 R15 tyres – predicted external radius = 310•75 mm (18•5 mm more than 185/55 R15)

I have never had a front spoiler on my Triumph Toledo, but I certainly didn’t encounter said front-tyre interference problems at or close to full steering lock when using either Uniroyal Rallye 180 or Kelly-Springfield Steelmark brands of 175 SR13 (possibly interpreted as either 175/80 R13, 175/82 R13 or 175/83 R13) tyres on the 5½ x 13 inch Cosmic alloy wheels (21 mm wheel-offset).

Although these 175 SR13 tyres would be expected to have had a larger external radius than your 185/60 R15 tyres, it’s very likely that the 175 SR13 tyres would have had a smaller installed section-width than your 185/60 R15 tyres.

I similarly didn’t encounter said front-tyre interference problems at or close to full steering lock, with the 185/70 R13 Firestone S211 tyres, on either the 5½ x 13 inch Cosmic alloy wheels (21 mm wheel-offset) or the 5½ x 13 inch Triumph Dolomite Sprint alloy wheels (35 mm wheel-offset).

I cannot predict what might have occurred if I had had the 175 SR13 tyres on the 5½ x 13 inch Triumph Dolomite Sprint alloy wheels (35 mm wheel-offset) or on 13 inch wheels of various widths (e.g. 5, 5½ & 6 inches) and wheel-offsets within the 20~35 mm range!?!

Quote:
I also quite like my existing substitute 5½ x 13 inch Dolomite Sprint wheels (35 mm wheel-offset), but the long-term availability and relative cost of appropriate replacement 185/70 R13 or 175/70 R13 tyres, combined with my desire to have a slightly-lower-profile tyre, of larger external circumference [mainly for reason of overall engine gearing] similar to that of my “original” 175 SR13 tyres, dictated the use of 15 inch wheels & 185/65 R15 tyres; a potential combination I had identified back in the early-1980s.

Now that I have the Triumph 1500TC Automatic rear axle with 3•89:1 final-drive ratio (or so I’ve been told) available as an option, the use of 185/65 R15 tyres is less critical with regard to overall engine gearing and associated average fuel economy, but I am still wary of using particularly low-profile tyres with reference to ride-comfort and susceptibility to tyre & wheel damage from kerbs, potholes, speed-humps and general road debris.

The following gear-ratio calculator, concurs with my assertion that using a 3•89:1 final-drive ratio in conjunction with 155 SR13 standard-profile tyres (said to be 82~83% aspect-ratio) or 185/55 R15 tyres, is almost exactly equivalent to using a 4•11:1 final-drive ratio in conjunction with 175 SR13 standard-profile tyres (said to be 82~83% aspect-ratio) or 185/65 R15 tyres.

https://tiresize.com/gear-ratio-calculator/

It would be interesting to know how a Triumph Toledo 1300’s average fuel economy varies, when a 3•89:1 final-drive ratio substituted for the original 4•11:1 final-drive ratio, is used in combination with either 185/55 R15, 185/60 R15, 185/65 R15, 175/55 R15, 175/60 R15 or 175/65 R15 tyres; bearing in mind the findings of the early-1980s wheel & tyre conference paper, which concluded that 65-Series tyres gave the least rolling resistance, compared with 80-Series, 70-Series & 60-Series tyres of the “same” external circumference!?!

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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PostPosted: Sun Jun 26, 2022 5:23 pm 
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Joined: Tue May 06, 2014 4:38 pm
Posts: 535
Location: South Benfleet, Essex
Classic Cosmic Alloy Wheels for Various Triumph Cars

It has previously been mentioned, that when my ex-demonstrator, 1974 Triumph Toledo 1300 “HL Special”, was purchased in May 1975 by my father, from Mann Egerton in Leigh-on-Sea, Essex, it came already retro-fitted with 5½ x 13 inch Cosmic alloy wheels & 175 SR13 Uniroyal Rallye 180 tyres.

Triumph Spitfire with Cosmic alloy wheels of the same style as those fitted to my 1974 Triumph Toledo 1300

Image

Cosmic 4-stud alloy wheel with same style of centre cap as mine

Image

In the July 1972 brochure, the following Cosmic LM25 aluminium-alloy wheels are listed for the Triumph Herald, Vitesse, Spitfire, GT6, Toledo & Dolomite, requiring wheels having a 4 x 3¾ inch (i.e. 4 x 95•25 mm) PCD – pitch circle diameter with four fixing holes; with the caveat that use of the 6 x 13 inch wheels might require bodywork modifications.

July 1972 Cosmic alloy wheels & accessories brochure

http://mk1-performance-conversions.co.u ... ls1972.pdf

The same wheel sizes, PCD and part numbers, are also specified for the Morris Marina. The generic wheels of size 5½ x 13 inches, are said to have an inset (or negative offset) of 0•875 inches (i.e. 22•225 mm) which is close to my measured value of 21 mm offset, for the Cosmic alloy wheels (of the same style as illustrated in the 1972 brochure) fitted to my 1974 Triumph Toledo 1300.

Size (inches) - - PCD - - - - - - - Inset (inches) - - Approx. Weight - - - Part No.

5 x 13 - - - - - - 4 x 3¾ inch - - - 0•75 ??? - - - - - 11 lbs 8 ozs - - - - - RW044/014

5½ x 13 - - - - - 4 x 3¾ inch - - - 0•875 ??? - - - - 12 lbs 0 ozs - - - - - RW027/023

6 x 13 - - - - - - 4 x 3¾ inch - - - 1•031 ??? - - - - 13 lbs 8 ozs - - - - - RW024/040

The brochure specifies radial-ply tyres of size 165 x 13 and 175 x 13, as suitable for use on the 5½ x 13 inch Cosmic alloy wheels, which is probably why in 1974/75 Mann Egerton in Leigh-on-Sea, Essex, fitted 175 SR13 Uniroyal Rallye 180 tyres to the 5½ x 13 inch Cosmic alloy wheels on my 1974 Triumph Toledo 1300, rather than 175/70 SR13 tyres as fitted to Dolomite Sprint wheels.


From the remainder of the table which follows, it is apparent that the wheels (4 x 4½ inch PCD) intended for the Triumph TR4, TR5, TR6, Stag, 2000, 2•5 & 2•5 PI, would be incompatible with the Toledo & Dolomite.

In the July 1972 brochure, the following Cosmic LM25 aluminium-alloy wheels are listed for the Triumph TR4, TR5 & TR6, requiring wheels having a PCD – pitch circle diameter with four fixing holes, of 4 x 4½ inches.

Size (inches) - - PCD - - - -- - - - Inset (inches) - - Approx. Weight - - - Part No.

6 x 15 - - - - - - 4 x 4½ inch - - - 0•31 ??? - - - - - 15 lbs 14 ozs - - - - RW031/057


In the July 1972 brochure, the following Cosmic LM25 aluminium-alloy wheels are listed for the Triumph 2000, 2•5 & 2•5 PI, requiring wheels having a PCD – pitch circle diameter with four fixing holes, of 4 x 4½ inch; with the caveat that wheel spacers might be required, especially for the early 2000.

Size (Inches) - - PCD - - - -- - - - Inset (inches) - - Approx. Weight - - - Part No.

5 x 13 - - - - - - 4 x 4½ inch - - - 0•75 ??? - - - - - 11 lbs 8 ozs - - - - - RW044/017

5½ x 13 - - - - - 4 x 4½ inch - - - 0•875 ??? - - - - 12 lbs 0 ozs - - - - - RW027/026

6 x 13 - - - - - - 4 x 4½ inch - - - 1•031 ??? - - - - 13 lbs 8 ozs - - - - - RW024/043


In the July 1972 brochure, the following Cosmic LM25 aluminium-alloy wheels are listed for the Triumph Stag, requiring wheels having a PCD – pitch circle diameter with four fixing holes, of 4 x 4½ inches.

Size (Inches) - - PCD - - - - - - - - Inset (inches) - - Approx. Weight - - - Part No.

5½ x 14 - - - - - 4 x 4½ inch - - - 0•88 ??? - - -- - - 15 lbs 8 ozs - - - - - RW026/031

_________________
Regards.

Nigel A. Skeet

Independent tutor of mathematics, physics, technology & engineering, for secondary, tertiary, further & higher education.

https://www.linkedin.com/profile/view?id=308177758

Upgraded 1974 Triumph Toledo 1300 (Toledo / Dolomite HL / Sprint hybrid)

Onetime member + magazine editor & technical editor of Volkswagen Type 2 Owners' Club


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