Optimum Wheel and Tyre Size

[Overhere]

Ok all, I have to say this subject has been bugging me for ages. I am look for new wheels and tyres, I do track days so it's not JUST about looks, but of course looks are part of it. I'm currently running Ford RS Soft Spokes 17" for road and use my Estorils for track.

The problem with any 17" front option is the unfortunate lack of a 225 width tyre in 17, I like the RS 17's (I'd post a photo but can't be bothered with all that using of a photo host crap) but at first I noticed the front's looked out of proportion, a bit too big for my taste, I've got used to it and would be happy but I'm running 245s on the rear and the 215s on the front, I think, are too narrow.

On my Estoril I run 225/50/15 and 245/45/16 and I like them, had R888s 2 years ago and loved them to bits, I now run the Hankook RS32s, which are ok (better than standard Proxy's)

To me, the optinmal sizes are 225/40/16 (on 7 or 7.5" rims) front and 245/40/17 (on 7.5 or 8" rims) rear. I like a fairly standard look like the Estoril, RS Soft Spoke, RaceLine RL7 etc. I've seen options with 17 front and 18 rear, they look a bit too pimped out for me, but even if I got used to it, same problem, 215 on the front is too narrow for me.

Can anyone help with options, suggestions, suppliers, etc?

Thanks!

[v8 racing]

Overhere said:

Ok all, I have to say this subject has been bugging me for ages. I am look for new wheels and tyres, I do track days so it's not JUST about looks, but of course looks are part of it. I'm currently running Ford RS Soft Spokes 17" for road and use my Estorils for track.

The problem with any 17" front option is the unfortunate lack of a 225 width tyre in 17, I like the RS 17's (I'd post a photo but can't be bothered with all that using of a photo host crap) but at first I noticed the front's looked out of proportion, a bit too big for my taste, I've got used to it and would be happy but I'm running 245s on the rear and the 215s on the front, I think, are too narrow.

On my Estoril I run 225/50/15 and 245/45/16 and I like them, had R888s 2 years ago and loved them to bits, I now run the Hankook RS32s, which are ok (better than standard Proxy's)

To me, the optinmal sizes are 225/40/16 (on 7 or 7.5" rims) front and 245/40/17 (on 7.5 or 8" rims) rear. I like a fairly standard look like the Estoril, RS Soft Spoke, RaceLine RL7 etc. I've seen options with 17 front and 18 rear, they look a bit too pimped out for me, but even if I got used to it, same problem, 215 on the front is too narrow for me.

Can anyone help with options, suggestions, suppliers, etc?

Thanks!

Hi jack just quickly you dont need hosting sites anymore for pics, just upload from your pc

[spend]

235 40 is a far better match than 225 50 IMHO & in plentiful supply, just run 255's on the rear to balance, should all be ok as long as you don't have too skinny rims...

[M@H]

Surely a 235 on a 17 on the front is going to rub on hard cornering !?? Saying that it all depends on the individual cars body fit.

Edited by M@H on Wednesday 21st September 21:10

[spend]

The sizes are nominally relative to the width / height but tyres are actually rounded & bouncy in cross section so the 10mm width is not simply 5mm less clearance etc.. when inflated, squidged under load & 3d'd Most arch wear & contact with rubber I've seen is due to height rather than width anyway (including running cars too low)?

[Overhere]

I don't think 255's will fit on 7.5" rims, the 245s already bulge at the sidewall. and 235 on the front will have quite a bit larger circumference than the datum of the standard set-up

PS Thank Rob for pointing out the new picture uploader, nice to be talking about something other than my ECU ;-)

[TV8]

Hi, not sure about the tyres but would be interested in a close up of the roll bar. It looks like it sits behind the seat more than some I have seen. Thanks

[Overhere]

Not quite behind, but I can tell you I agonised with roll bar designs for both fit and rigidity for ages. Tim Lane, TR Lane Fabrications, Tim is super nice and will do a custom for you like he did for me, very reasonable, no brainer

[M@H]

spend said:

The sizes are nominally relative to the width / height but tyres are actually rounded & bouncy in cross section so the 10mm width is not simply 5mm less clearance etc.. when inflated, squidged under load & 3d'd Most arch wear & contact with rubber I've seen is due to height rather than width anyway (including running cars too low)?

I suppose quite a bit will depend on the offset of the wheels - I have some 17's to fit at some stage and agonized over the 215 / 235 issue, I have not bought any tyres yet as I don't want to blow a pile of cash and find they catch somewhere.

[JR]

M@H said:

I have some 17's to fit at some stage and agonized over the 215 / 235 issue, I have not bought any tyres yet as I don't want to blow a pile of cash and find they catch somewhere.

For 17s the optimum front wheel (as in the nearest that the chassis designer intended) is likely to be 215/40 on 7.5J rim with a 25mm offset.

[Jammy Dodger]

i've just been through this, but based on 8J F17, 9J R18 (to allow big front brakes)

Steve Guglielmi picked 225/45/17 and 255/35/18 as the sweetest compromise for mine.

so, 225 is available on 17s, but at 45 section

it was also established that 215/40 would be an option - would work well on a 7/7.5J

Edited by Jammy Dodger on Thursday 22 September 08:57

[M@H]

JR said:

For 17s the optimum front wheel (as in the nearest that the chassis designer intended) is likely to be 215/40 on 7.5J rim with a 25mm offset.

Thanks for that, I had mentally opted for 215 anyway

[CHIMV8]

M@H said:

Thanks for that, I had mentally opted for 215 anyway

Could you get away with 225 45/50 on the front to make tyre wall deeper and the ride a little less hard?

[JR]

CHIMV8 said:

M@H said:

Thanks for that, I had mentally opted for 215 anyway

Could you get away with 225 45... on the front to make tyre wall deeper and the ride a little less hard?

Yes but that would be thread deviation.

[CHIMV8]

JR said:

Yes but that would be thread deviation.

Whats that mean?