Tread Depth for Track Day Tyres
Discussion
OK, so I've got SO2's all round at the moment and the rear tyres are about half a mil above the depth indicator. I reckon I can definitely get one more track day out of them no probs, but what is the optimal tread depth for a track day? When I get some new boots for the Griff, will it be worth hanging on to the old rubber for track use?
Using my miniscule laymans knowledge I figure that the tread is essentially there to shift water, so slicks will give the best performance in the dry, and the wetter it gets the more tread you need, but I'm wondering if well-worn road tyres give the same kind of in-the-dry improved grip as dedicated slicks (albeit in a less sticky way) or if it's just like driving around on wire mesh...
I asked exactly the same question and the riot police had to be called in!
If I were you I'd wear the worn ones and keep a close eye on them. Then Id take a new set and change to them if necessary.
But then Im no trackday hero.
Don't intend to be either! Its only a bit of fun.
I have still got my 3-4mm S02s in the garage and am waiting for some wheels for them. Anyone got any?
If I were you I'd wear the worn ones and keep a close eye on them. Then Id take a new set and change to them if necessary.
But then Im no trackday hero.
Don't intend to be either! Its only a bit of fun.
I have still got my 3-4mm S02s in the garage and am waiting for some wheels for them. Anyone got any?
Obviously I'm super vigilant about only using legal tyres on the road. I just have the same idea as you Adam about keeping a pair of dedicated trackday wheels and I'm trying to figure if it's actually worth it or not.
I've also heard that brand spanking new tyres will be wrecked (and unsafe) if taken out on track before being run in...
I've also heard that brand spanking new tyres will be wrecked (and unsafe) if taken out on track before being run in...
Yeah, thats true about new tyres. They are even crap on the roads.
Im trying to decide if dedicated track day wheels are necessary now too. May as well just get through the road tyres (S03s) I suppose.
Then again, if we had dedicated trackday wheels we could use things like R888s or A0348s.
(The "almost" slick type tyres you usually see on trackday specials).
Im trying to decide if dedicated track day wheels are necessary now too. May as well just get through the road tyres (S03s) I suppose.
Then again, if we had dedicated trackday wheels we could use things like R888s or A0348s.
(The "almost" slick type tyres you usually see on trackday specials).
On a dry track the tread blocks on a newish tyre move about and contribute to overheating. The deeper the tread, the worse this problem will be. If you are using road tyres a well worn set are ideal (provided it doesn't rain!).
But you need to be careful that you don't inadvertently wear through to the canvas - and of course you shouldn't use illegal tyres on the road.
But you need to be careful that you don't inadvertently wear through to the canvas - and of course you shouldn't use illegal tyres on the road.
, weather conditions permitting? The other problem with well worn tyres that are on the limit is the tread is often old and hard which doesn't help. If the tread is gone you don't get slicks or slick performance... you just get reduced grip.
There is also little room for mistakes. A good lock up or spin and it is possible to go straight through to the canvas because there is so little tread.
The wear patterns also tend to be assymetric with the inside edges wearing first. The outsides can look fine but the inners could be a couple of mmm down. On a tyres with only 2 mm that can make life interesting as the worn edge will have very little grip at all and will be all over the place in slippy conditions.
All in all... 2mm tread tyres are not really practical for track days unless you have a spare set and are aware of their limitations.
There is also little room for mistakes. A good lock up or spin and it is possible to go straight through to the canvas because there is so little tread.
The wear patterns also tend to be assymetric with the inside edges wearing first. The outsides can look fine but the inners could be a couple of mmm down. On a tyres with only 2 mm that can make life interesting as the worn edge will have very little grip at all and will be all over the place in slippy conditions.
All in all... 2mm tread tyres are not really practical for track days unless you have a spare set and are aware of their limitations.
The S02s have a dual compound tread with a hard outer layer and a softer layer underneath. There is a sweet spot at about 2mm where you run on the soft part of the tread. This is also the point where there is relatively little deflection in the tread so the tyre has more ultimate grip but tends to be a little snappy for some people. Be aware though that as you get down past the wear indicators and start running on the carcase instead of the tread, the rubber compound changes again and the tyre loses a lot of grip. Worn out road tyres are NOT the same as slick racing tyres! You also need to be very careful about uneven tyre wear as Steve pointed out because once you start running on the carcase you can get very rapid wear and before you know it you've got a catastrophic failure.
>> Edited by greenv8s on Friday 30th July 12:53
>> Edited by greenv8s on Friday 30th July 12:53
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