Quote:
These are an inch wider than the standard steel wheels.
https://www.johnbrownwheels.com/product ... 5513SMO495
185/60s would fit nicely on them.
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Not sure if the offset is right but TR7s had 185/70s on the later models. They should work?
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For many years I used 185/70 R13 tyres on 5.5 x 13 inch Cosmic wheels (21 mm offset) and later 5.5 x 13 inch Dolomite Sprint wheels (35 mm offset), fitted to my 1974 Triumph Toledo 1300 "HL Special". These tyres are still readily available, but I anticipate that this will change noticeably over the next few years, so I intend to substitute 5.5 x 15 inch MG 2000 Maestro alloy wheels (31 mm offset) in conjunction with either 185/65 R15, 185/60 R15 or 185/55 R15 tyres, of which the former are the most readily available.
On the 5.5 x 13 inch Cosmic wheels (21 mm offset), the tyres rubbed against the rear wheel arches, when carrying rear-seat passengers and/or heavy luggage in the boot.
185/60 R13 or 185/70 R13 tyres would fit on these okay, but with a
wheel-offset of ONLY 20 mm, the tyres
WILL almost certainly rub against the rear wheel arches; especially if carrying rear-seat passengers or heavy luggage.
Strangely, the "Smoothie" 5½ x 13 inch steel wheel, is said to have a
centre-bore diameter of 157 mm, which seems inordinately large!
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
Ideally, you should be using wheels whose wheel-offset is much closer to 35 mm, like my 5.5 x 15 inch MG 2000 Maestro wheels of
31 mm wheel-offset, on which one could use 185/65 R15, 185/60 R15 or 185/55 R15 tyres, which are likely to be readily available at reasonable prices for many years to come, unlike tyres for 13 inch wheels.
Another potential disadvantage of retaining 13 inch wheels, is that there would probably only be
summer tyres available for them, but for 15 inch wheels one can obtain either
summer,
winter or
all-season tyres.
Checking on MyTyres.com, I found the following options:
https://www.mytyres.co.uk/
185/80 R13 – 90S | 1 result
https://www.mytyres.co.uk/search?sortCo ... eTypes=OFF
Maxxis MA1 | P185/80 R13 90S WSW 15mm | summer tyres | £105•69
175/80 R13 – 86S or 175/80 R13C - 97/95R | 2 results
https://www.mytyres.co.uk/search?sortCo ... iews=false
Maxxis MA 1 | P175/80 R13 86S WSW 15mm | summer tyres | £ 107•89
HI FLY Super 2000 | 175/80 R13C 97/95R | commercial-van summer tyres | £46•99
165/80 R13 – 83T or 87T XL | 22 results
https://www.mytyres.co.uk/search?sortCo ... eTypes=OFF
155/80 R13 – 79 T or 83 T XL | 48 results
https://www.mytyres.co.uk/search?sortCo ... eTypes=OFF
175/70 R13 – 83 T or 82 H | 53 results
https://www.mytyres.co.uk/search?priceC ... &season=so
185/70 R13 – 86 T | 17 results
https://www.mytyres.co.uk/search?sortCo ... iews=false
185/65 R14 – 86 T or 86H | 135 results
https://www.mytyres.co.uk/search?sortCo ... iews=false
185/60 R14 – 82 T or H or 86 H XL | 131 results
https://www.mytyres.co.uk/search?sortCo ... iews=false
185/65 R15 – 88 T or 88 H or 92 T XL or 92 H XL | 290 results
https://www.mytyres.co.uk/search?sortCo ... iews=false
185/60 R15 – 84 T or 84 H / 88 T XL or 88 H XL | 209 results
https://www.mytyres.co.uk/search?sortCo ... ologation=
185/55 R15 – 82 T, 82H or 82V / 86 H XL or 86 V XL | 132 results
https://www.mytyres.co.uk/search?sortCo ... ologation=
175/65 R15 – 84 T or 84 H / 88 T XL or 88 H XL | 146 results
https://www.mytyres.co.uk/search?sortCo ... eTypes=OFF
175/60 R15 – 81T or 81 H or 81 V / 85 H XL | 38 results
https://www.mytyres.co.uk/search?sortCo ... eTypes=OFF
175/55 R15 – 77 T, 77 H or 77 V / 81 T XL | 44 results
https://www.mytyres.co.uk/search?priceC ... 15&season=
In a 14-page, A5-format magazine technical article [published in either the Automobile Association’s “DRIVE” magazine or Motor-Caravanners’ Club’s “Motor-Caravanner” magazine, but believed to be the former] dating from early-1992, I found a statement that for standard-profile tyres such as 155 SR13 (later re-designated 155 R13), the aspect ratio was 82%, which is consistent with the 82% & 83% that I found in various papers, that were published in a wheel & tyre industry engineering conference proceedings from the early-1980s.
185 R13 => 185/83 R13 – overall external circumference = 2002•1 mm
185 R13 => 185/82 R13 – overall external circumference = 1990•5 mm (8•42% larger than 155/82 R13)
185 R13 => 185/80 R13 – overall external circumference = 1967•2 mm
175 R13 => 175/83 R13 – overall external circumference = 1949•9 mm
175 R13 => 175/82 R13 – overall external circumference = 1939•0 mm (5•62% larger than 155/82 R13) [Nigel’s tyres from 1975 to 1987]
175 R13 => 175/80 R13 – overall external circumference = 1917•0 mm
165 R13 => 165/83 R13 – overall external circumference = 1897•8 mm
165 R13 => 165/82 R13 – overall external circumference = 1887•4 mm (2•81% larger than 155/82 R13)
165 R13 => 165/80 R13 – overall external circumference = 1866•7 mm
155 R13 => 155/83 R13 – overall external circumference = 1845•6 mm
155 R13 => 155/82 R13 – overall external circumference = 1835•9 mm
155 R13 => 155/80 R13 – overall external circumference = 1816•4 mm
185/70 R13 – overall external circumference = 1851•0 mm (0•82% larger than 155/82 R13) [Nigel’s tyres from 1987 onward]
175/70 R13 – overall external circumference = 1807•0 mm (1•57% smaller than 155/82 R13) [factory-fitted tyre size on Dolomite Sprint]
175/65 R13 – overall external circumference = 1752•0 mm (4•57% smaller than 155/82 R13)
185/60 R13 – overall external circumference = 1734•7 mm (5•51% smaller than 155/82 R13)
175/65 R14 – overall external circumference = 1831•8 mm (0•22% smaller than 155/82 R13) [MG-F & MG-TF space saver spare]
175/65 R15 – overall external circumference = 1911•7 mm (4•13% larger than 155/82 R13)
175/60 R15 – overall external circumference = 1856•7 mm (1•13% larger than 155/82 R13)
175/55 R15 – overall external circumference = 1801•7 mm (1•86% smaller than 155/82 R13)
185/65 R15 – overall external circumference = 1952•5 mm (6•35% larger than 155/82 R13)
185/60 R15 – overall external circumference = 1894•3 mm (3•18% larger than 155/82 R13)
185/55 R15 – overall external circumference = 1836•2 mm (0•02% smaller than 155/82 R13)
_________________
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