TYRE SIZE

[bindy]

Ok what is the smallest tyre size front/rear on a gt12 as i have been asked by a few people when to bin them me i run till i cant get the correct ride hight but others have give different sizes so just wondering what other peoples ideas are
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bindy

[westie]

Till you can see the wheel through the tyre

[SlowOne]

If it's on a Mardave then you can just about get down to 44mm front and 45mm rear. If it's on a SupaStox then you'll need to be at least 1mm above that.

The tyres are no longer suitable when you can't achieve 3mm of ride height at both ends. That's the only guide you need. HTH

[KJR]

You can go really tiny on a mardave especially if you fit the front wishbones to the chassis directly and not the camber plate thingy.

Currently have 44mm rear and 43mm front on my car with 4mm ride height all round. Have a ride height spacer on the front so could let them wear more and still maintain height.

They do generate a lot less grip when they are smaller though so there does come a point where you need to get back to bigger tyres to generate the grip if you run without additive like I do.

The great thing is that they started at 48 rear, 46 front so you can get loads of races out of the tyres on a mardave.

[JimboJames1972]

Tire diameters have nearly as much impact on handling as the compound does.

Usually, a larger diameter will give more grip - a thicker sidewall will flex and deform as the tire is loaded which, in turn, will give a bigger tire contact patch and so more grip.

This is fine in low grip conditions, but many drivers prefer the more "direct" feel that smaller tires can give. This is why many drivers choose to skim their tires down to smaller diameters, especially if the grip levels are higher.

Lastly, most drivers consider that a car drives better with rear tires a millimetre or two bigger in diameter than the fronts.

When running standard Mardave rims I start my tires at 49mm diameter on the rear and 47mm diameter at the front for club running (low to medium grip). If I am running at the Nationals or at other very high grip tracks I use rears that are closer to 46mm and fronts as low as 44mm. I can go lower on both before I run out of physical ride height (i have the adjustable rear pod and use 1mm washers under the front late rather than nuts) but there is soooooooo little side wall left on the tires by this point that the car loses performance.

Hope this helps,

James

[oakey4]

If you running a carbon kit, do away with the front carbon bit and mount the wish bones straight onto your classic, then put a 2.5mm nut/washer under the front hole to give you your caster. Also try and have the rear wheels 2mm larger than the fronts. Hth, this is what all the lads do at our club and we have good close racing.