Best tyre size for 18" Spiders at the rear?

[sprevett]

When I got the car from TVR, Neill A had fitted 18" spiders on the back and it was shod with fairly fat rubber (he used the car for sprinting amongst other things) - but I fitted slightly smaller tyres as there was evidence of the tyres fouling the arches under heavy cornering. I fitted 245/35/18 Goodyear F1's which have been good, but I later discovered that the rear Nitron shocks were seized, so now that I have new Nitrons all round I am pondering going back to a wider profile (on the assumption that if slight adjustment is needed I can fiddle with the shocker settings) - it looked great and grip was amazing with the bigger rubber - so I am considering going up to a 265/35/18 Toyo T1R. I can't remember what size it had on before - but it cant have been any bigger than that, and according to a tyre size calculator the difference in diameter is only 14mm if I go to a 265/35, which shouldn't be a big deal?

Has anyone else got 18" rears on a Griff and if so, what tyre size are you running?
Steve

[sprevett]

By the way I noticed on previous topics that some folk had opted for 255/35/18 but cant find that size on a Toyo T1R....

[Murph7355]

I have 265s and I think they might be a tad wide. They can foul the arches, which I don't think is suspension related.

I'd probably stick with 245s personally (will likely try them when I wear the current tyres out).

[eff eff]

www.Toyo.co.uk list 255/35/18 T1R 636 mm overall diameter

[pxw]

On mine Rear wheels all round, 5mm spacers on the front and 245/40/18 rear 225/40/18 Goodyear F1 GSD3s all round no fouling
Gordon
www.pxwheels.com

[sprevett]

Thanks guys - you're right Toyo do list a 255/35/18, so that's got to be favourite as I agree 265 probably pushing it and I really don't want fouling issues again. Will keep you posted...

[steve-V8s]

The first thing you need to know is how wide the rims are, then you can ask what is optimum and what is allowable for a particular type of tyre on that size of rim. The larger the diameter and therefore the lower the profile the more important it is that you match the rubber width to the rim width. At a guess, to get a 265 on an 18 inch it will need to be at least 10 or 11 inches wide, which is rather wider than the 7.5 originally fitted.

[sprevett]

yes i was wondering about that...anyone know the width of a TVR Anthracite 18" Spider rim?

[Ant.]

8.5" steve

[steve-V8s]

From the Toyo website

R888

255/35ZR18 94Y XL 2G 2389209 5.0 637 260 8.50-9-10.00

T1r

255/35ZR18 94Y XL 2389300 8.2 636 257 8.50-9-10.00


A 245 on a 16 X 7.5 rim would probabaly work better however.

[sprevett]

thanks guys - does that mean a 255 will be ok on an 8.5" Spider?
and are you recommending I go wider on the fronts from a 225 to a 245? (the 16" rims are Spiders too)
cheers,....

[Big Ashy]

I have 225/35/18 on the front and 245/35/18 on the rear, no fouling issues on arches but fitted rack stop shims to prevent slight fouling on chassis at full lock.

[dbv8]

I sometimes run 255's on the original 7.5 rims.
Wouldnt want to corner hard on these tho



I had some fouling problems so did a butchers job on my inner arches.