Track Day Tyre Size - Help Needed

[Gary H]

Hi - I need to get some tyres for a weekend at the Nurburgring and Spa this weekend and have just been told that my preferred tyres are out of stock in the standard sizes.

I'm running a pair of 987 17's (6.5's and 8.5's IIRC) and was going for a pair of 205/50's and 255/40'17's.

I've been offered the following:

Option 1:

215/45/17 & 235/45/17

Option 2:

225/45/17 & 245/40/17

My only concerns are: will a 235 be too narrow for the rear - and will a 225 be too wide for the front?

I need to do something today, so any help appreciated.

[pk2]

Don't know the answer off hand but you can do the math and find out for your self.

The "45" in "235x45x17" is 45% of the "235"(mm circumference).

So the side wall height is 45% of 235mm or .45 x 235. That equals 105,75mm side wall height. Subtract that from "235"mm and you have a tire 129mm wide.

So in this case; 235 - (.45x235) =129. Add the mm and you have129mm tire width...magic! Plug in your other and have fun.

Regards, PK

Note, the 105mm side wall includes about 20mm hidden behind the rim lip

Edited May 24, 2010 by pk2

[Topless]

Option #2- 225F/245R will be fine. I have run 255/17 Rcomps on the front with no rubbing issues. What would I shoe my Boxster in for Spa and Nordschleife? Kumho V710 255/17 all around...Not the ideal choice for everyone and the 255s will not fit on your front wheels.

[Gary H]

Thanks - I looked at the Kumho because the R888's are out of stock. The only thing I could get were Hankook R-S2's which I've used before, as the V70's were out too. Then they ring me back and say I can have 3 tyres :)

So now I'm stuck with a decent road tyre rather than a track-oriented option.

An instructor said he'd heard good things about Vredestein Sessantas - in the option 2 sizing, they work out at £250 as opposed to £850 for the R888's (remember we also pay $8 a gallon :) ) so I'll give them a go

[Topless]

Thanks - I looked at the Kumho because the R888's are out of stock. The only thing I could get were Hankook R-S2's which I've used before, as the V70's were out too. Then they ring me back and say I can have 3 tyres :)

So now I'm stuck with a decent road tyre rather than a track-oriented option.

An instructor said he'd heard good things about Vredestein Sessantas - in the option 2 sizing, they work out at £250 as opposed to £850 for the R888's (remember we also pay $8 a gallon :) ) so I'll give them a go

Have a great time! I have never run or even seen the Vredesteins so no opinion on them. R888s don't work very well for us out west though. Most drivers here prefer RA-1s, Nitto NT-01s, BFG R1s or the Kumho V710s in our sizes.