Original tyre sizes

[Jim Cowden]

I have done searches but have got nothing out of that.
I am after the original tyre sizes on say Gulf cars or similar race cars (mk1) so as I can work out a rolling diameter for my tyre choice.
I will thank you in advance.

Jim

 

[Malcolm]

I understand where you are coming from on this, but was there really an original tyre size? Did it not change accordng to the latest bestest rubber available for the next race? This could be like looking for the right blue for the Gulf paint. 1075 is not the same colour now as it was when it won Le Mans! You may find you need to look at rubber that is available now and then work out what looks right (in your mind) for your car. Especially for road rubber. But good luck in your hunt.

 

[Al Jones]

Jim, I saw an article claiming the '66 Mk 2's carried Goodyear 'A' 9.75-15 and 12.8-15.May have been the same on Mk 1.

 

[Russ Noble]

Hi Jim,

Malcolm's right, tyres would be constantly changing.

In 1969 the JW Gulf cars were running 10'' and 14" rims. Dunlops of the time for those rims would have been treaded CR82s, 430/1160-15 fronts and 530/1500-15 rears. Rolling diameters 23.7" and 25.5" respectively. These are still available through Dunlop. Firestones would have probably been the ubiquitous YB11s. Not sure what sizes they would have been, but similar, I would venture.

Out of interest, how much later did slicks come in? And did any GT40s run them in the day?

Cheers,

Russ

 

[Trevor Booth]

In the original "ford that beat ferrari " book
JWA cars in 68 ran 10" front, 12" rear rims , with 10.30-15 front and 13.50-15 rear tyres, in 69 rims were 10"front, 14" rear with 4.25/10.30-15 front and 6.00/13.5-15 rear.
Tyres were Firestone brand