PCD change?

[xvivalve]

The studs sit just inside a shoulder of the hub casting and extending outwards even by only 2.375 mm may encroach onto the chamfered area…

[Carledo]

The studs sit just inside a shoulder of the hub casting and extending outwards even by only 2.375 mm may encroach onto the chamfered area…

I'm aware the tolerance is tiny on an original steel hub, even an original 3/8" stud at 95.25mm looks, to my eyes, perilously close to the edge. However, since i've loaded my 7/16" studded standard hubs quite considerably over many years without a sniff of trouble, i'm willing to believe appearances are deceptive!

But my comment, or suggestion was more aimed at the Sprintspeed alloy hubs, which, being alloy and therefore more malleable under stress loads, might be made with a bit extra reserve metal that could be worked with!

Steve

[xvivalve]

The studs sit just inside a shoulder of the hub casting and extending outwards even by only 2.375 mm may encroach onto the chamfered area…

I'm aware the tolerance is tiny on an original steel hub, even an original 3/8" stud at 95.25mm looks, to my eyes, perilously close to the edge. However, since i've loaded my 7/16" studded standard hubs quite considerably over many years without a sniff of trouble, i'm willing to believe appearances are deceptive!

But my comment, or suggestion was more aimed at the Sprintspeed alloy hubs, which, being alloy and therefore more malleable under stress loads, might be made with a bit extra reserve metal that could be worked with!

Steve

Yes, but the two stud sizes sit in the same sized holes at identical PCD as standard and therefore with the same margin to the chamfer. The right grade of aluminium alloy could prove stronger than cast steel.

[ian.stewart]

Most of my motoring life I have been in the ford stable, but with retirement money is tighter
Here's another thought, I have obviously been looking at hubs everywhere within the internet I can find, there are a few people knocking out ALLOY hubs with different PCDs, well another PCD, Ford.......108mm. and why ONLY FORD, there are so many changeover items between manufactures that if people knew a lot of affordable non ford bits would go thru the roof, .... I digress, most of these alloy hubs do look like the Rally Design items that have been knocking about for years, Im wondering if this hub is a changeover item, Im fairly certain one of the bearings are the same as Triumph, the inner/larger one, and with a bit of research in the SKF catalogue I would not be surprised if there was a bearing that has the right dimensions to swap,

[sprint95m]

I am hoping to get somewhere in the 300mm disc size, I have a pair of aftermarket discs for a cosworth 295mm I think, and a pair of ambassador 4 pots too, not shedding weight but better than some alloy bembros I have had,

Not sure about this...
Ambassador calipers are a four piston version of a T2000 caliper, offering no more braking force.

If you are not bothered by their weight,
Jaguar XJ12 have bigger four piston calipers intended for bigger discs.....



Ian

First thing I will say is the clamping force is variable by altering the master cylinder bore size, fitting a servo, how hard you push the pedal or altering the pedal ratio to do so, they will all have an impact on clamping pressure, in reality its a balance between locking the wheels and knowing when they are about to lock.
Brakes, Generally, the area of pad is one of the benefits of 4 pots, by fitting big pads this gives more clamping area, and better heat dissipation. a bigger disc gives you more leverage against rotational forces and better heat dissipation, IMHO I will fit the biggest disc feasable just for that reason which in turn gives better feel too. for that reason. I never fit a servo either, they reduce pedal pressure but also reduce feel. and as they dont change the swept area of pad, or disc size, they dont actually improve your brakes ability to stop, just pedal pressure, and often forgotten in the equation, the final element of a braking system is tires, have small, skinny, hard, under or over inflated, that dont grip the road, the worlds best braking system aint worth a toss if the car is not gripping the tarmac. fit the best tires you can get.........
Princess callipers, they were the well known budget calliper that gave you bigger brakes, over the years I have had various brake setups, including princess callipers, which were superb, I, looking for a lighter setup changed the callipers to Porsche Bembros, almost the same swept area of pad and same piston displacement , the brakes went from stop on a sixpence ooooh im not liking this..........we eventually found out the Bembros flexed massively under load, where the cast iron princess ones did not,
Princess callipers,why I like them, they dont flex, there is a comprehensive range of pad material available, the pads are fairly big, piston volume is the same as a m16, so calculations for master cylinders is relatively easy, and the mounting the same as the M16
Braided brake lines normally have a impact too, as thy dont expand anywhere near as much as rubber ones,

You have missed my point I feel, fitting just Princess calipers alone to a T2000 makes no difference.
The pads and piston bores are the same.

Chris Witor did extensive testing in order to improve T2000 brakes.
He ended up offering two set ups,
one with Renault 30 discs and Jaguar XJ12 calipers
and the other using Wilwood calipers.

I am thinking if you are going to the bother of upgrading, why limit this improvement by choosing a small caliper
when there are inexpensive options designed for c.300mm diameter discs available today from the likes of Ford?


Thanks,
Ian