Tyre sizes for Superlight R

[clarkey]

I recently bought a second hand SLR from Caterham.

As a part of the deal they replaced the ACB10s with CR500s, and gave me the old tyres.

The ACB10s are 245/45-13 rear, 185/55-13 front

The CR500s are 205/50-13 rear, 175/55-13 front.

 

Is it usual for these tyres to be different sizes? Can 245s and 205s safely fit on the same rim?? The rolling radius of the two must also be different, so for which set will the gearing be correct?

 

Thanks for your help.

 

 

[EFA]

Stephen,

 

The full specs for the tyres are at:

 

http://www.avonracing.com/tyres/tyregroup.asp?ID=3

 

 

The sizes are only minimally different for the critical component which is dia of the rears 22.1inches for ACB10's and 21.8 for CR500's

 

Run one of the many gearing calculation programs (I've a dos one if you need it) and you will see .3 of an inch has little effect on speeds in gears.

 

 

 

Arnie Webb

The Fat Bloke blush.gif in a Slow Old Vauxhall wink.gif

[clarkey]

Arnie

 

Cheers for that, just the answer I was looking for.

 

Steve.