Wheel width v tyre width

[AlexF]

Whats the score here...

Specifically I have some 6x13 slicks and currently have some 8x13 wheels. I'm sure I read somewhere that over-wheeling was ok up to about 1".

Whats the likly effect of fitting 6" slicks to a 8" wheel in terms of handling, if it is possible in the 1st place?

Alex

[Warwick]

Avon dont recommend a rim larger than a 7"wide for a 6"wide tyre and best fitment is a 6"wide wheel.

You can just about fit any tyre to any rim (within reason) but the different widths will cause a difference in the contact patch and a difference in the amount of traction available.

[graham bahr]

its better to have the wheel on the wide side, as that will stretch the tyre and you will suffer far less tyre deformation. due to a shortage of slicks for most of this season i used 195 width slicks on 8" wheels which are techinally too wide but didn't have any negative side effects, certainly the car was much better than when last year i ended up using 220 tyres on 7 inch rims.

[Red Dog]

Alex I have been using 160 (6.25") slicks with 8"x 13" wheels for two seasons. Tyres are Yokos - I called them and they advised 8" was max size to stretch the tyres onto. Car handles very well and the very best thing is that my tyres seem to last significantly longer than my adversaries', and I am matching their lap times. Wear pattern is very good. Are your wheels 8" measured in between the flanges?

[Cryos]

Hmmm,

I use 6x14" Oz Racing and 5.5x14" Compomotives and 6x14" Speedlines on my nova, i use Avon 7x14" slicks on the Oz Racing (which is recomended for rallysports) and use 5x14 Monsoons on the compomotives (tall tire) and use 7x14" Avon Median Cuts (intermediate setup)...

In my expirence a size bigger is much better for handleing and grip (providing your using some form of power steering), if you use a size less your more prone to punctures/blow outs and have less grip....

Well thats my opinion..

[big andy]

alex f
r u using the tyres on a mini?

[AlexF]

I am yes... I changed to 13x6 wheels now, but haven't had a chance to try my slicks..

alex

[Kid Prozac]

using different width irims for a smaetyre will affect the cornering stiffness

for example:

say we have a 13" id 20"od tyre with a 7" contact patch on a generic wheel say 7" wide.

if we make changes to the front wheel/tyre combination:

If we go to a 6.5" rim, the cornering stiffness will be reduced, which assuming all other parameters on the carare the same, the slip angle of the tyre will increase, which will cause understeer.

Similarly, if we say go to a 7.5" rim, the cornring stiffnes will be increrased, reducing the slip angle, leading to an oversteer characteristic.

[big andy]

alix f
i race a mini on slicks 8x13 180x490x13 and also on 175x50x13 yoks 048rs on 7x13 and 8x13s. the slicks offer a bit more grip but take longer to warm up 2,3 laps which are interesting as the back end will come round at any opatunaty?.the 048rs on 7x13s or 8x13s r up to heat and gripping nearly rightaway say half a lap .the best lap times i have done at croft on slicks is 1.40 and 142.5 on the yoks.