widest tyre on bottletops?

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bmbartlett
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Thu Apr 01, 2010 12:19 pm

just wondering whats the widest tyre you can fit to a bottletop alloy wheel? 14" size wheel i think myn are
Grrrmachine
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Thu Apr 01, 2010 2:31 pm

considering the side wall is usually pretty large, you wouldn't want to go too oversize because you'll pop them on agressive corners. 185's are normal, 195 if you're feeling lucky, anything over that and I wouldn't want to be in the same car as you...
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Thu Apr 01, 2010 2:53 pm

i have 225's on the arse end of mine but 16" rims so i guess if you can buy them in 14's they'll fit but might rub ?
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Grrrmachine
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Thu Apr 01, 2010 3:01 pm

If the wheel itself is 16", you're won't have such a big sidewall as you would with a 14", and that's where the risk is - bulging and splitting from all the flexing the tyre sidewall has to do.
bmbartlett
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Thu Apr 01, 2010 7:21 pm

What's widest with a low profile tyre then?
da4x4turbo
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Fri Apr 02, 2010 6:49 am

Why not just buy a real set of rims? Problem Solved :D
Anyone who knows of an S50 B32/B30 E30 for sale, please let me know.
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Messenjah
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Fri Apr 02, 2010 12:07 pm

for 50 series tyres and above the rim width should be 70% the tyres section width for a normal road car

so theoretically that means a 205/50 or 55 tyre is the ideal size for a 6 inch rim
Grrrmachine
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Fri Apr 02, 2010 12:52 pm

And for rolling measurements, a 235width tyre is needed with a 50 sidewall to keep the rolling diameter the same; big differences otherwise affect the gearing of the car and the readout of the speedo.

Remember that the sidewall is a percentage, not a fixed height, so 50% of 235 is 117.5mm, whilst the sidewall of a 185/65R14 tyre (the ones properly fitted to bottletops) is only 120.25mm, so a low ratio tyre is still going to have a tall sidewall.

To keep the diameter right and the sidewall safe, you can use a 205/60R14 or 195/60R14. Anything wider that that is risking adverse cornering conditions, reduced acceleration and worse MPG, just to fit in with the phat boyz. Doesn't sound that smart.
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