Tyres gone hard, what to do.
Discussion
I would be interested to hear your opinions on this one guys as I have had all sorts of advice on this in the past. I only ran my car twice last year, the second time getting the tyres really hot but it was in hot weather and on a very abrasive service. I have a durometer and measured low 70's on my set of Dunlop DZ03g when new, the same after their first outing and same again in the days/weeks after the second outing last summer. They have been on the car since and through the winter but now read well into the 80s on the durometer and TBH they really do feel rock hard to touch, I can't even get my finger nails into the fronts. I have heard people say before you can recover tyres to some degree by driving on em enough to wear them down a bit more and put a couple of heat cycles on em, other opinions indicate they will never again produce grip like they did last summer. I thought from the conversations I have with various people that both are probably true to some degree. What say you?
Old tyres will never be as good as new ones. But running on them for a session will likely take to hardest top surface off. I think how badly they degrade will depend on the tire - I've had Toyos that were rock hard and not used for a year, but were perfectly fine when they'd had a 20 minute session one them. Just be careful when you first run on them as they'll be like ice.
We were lucky, I am in south Dorset and we had had double digit temperatures for a few days. ISTR it had been 12 degrees C that day and was in the afternoon when I measured them.
Thanks for the responses so far guys, I have read 80+ from this tyre type in the past when they were shot but I am hoping that after only been run on 2 days they have a good few heat cycles left in them.
Thanks for the responses so far guys, I have read 80+ from this tyre type in the past when they were shot but I am hoping that after only been run on 2 days they have a good few heat cycles left in them.
We were lucky, I am in south Dorset and we had had double digit temperatures for a few days. ISTR it had been 12 degrees C that day and was in the afternoon when I measured them.
Thanks for the responses so far guys, I have read 80+ from this tyre type in the past when they were shot but I am hoping that after only been run on 2 days they have a good few heat cycles left in them.
Thanks for the responses so far guys, I have read 80+ from this tyre type in the past when they were shot but I am hoping that after only been run on 2 days they have a good few heat cycles left in them.
it depends what you want to do with them after you've softened them up. you can use GRIP http://griptyresoftener.com/ but its banned in UK circuit racing, and the scruitineers will be able to smell it.
What I've done in the past is to set hot pressures when its cold, ie, if you run 32psi hot then set them at 32psi cold, then go out and t
t about until the car won't grip at all any more, then trim to the correct hot pressure, leave the car and tyres too cool (in between test sessions) then they will be significantly better for the rest of the day.
I tend to do this in the early test days of the year on last years tyres.
Also, does it really matter how soft or hard your tyres are cold? get them to race temp and pressure, then test the hardness.
What I've done in the past is to set hot pressures when its cold, ie, if you run 32psi hot then set them at 32psi cold, then go out and t
t about until the car won't grip at all any more, then trim to the correct hot pressure, leave the car and tyres too cool (in between test sessions) then they will be significantly better for the rest of the day. I tend to do this in the early test days of the year on last years tyres.
Also, does it really matter how soft or hard your tyres are cold? get them to race temp and pressure, then test the hardness.
I agree with wildman0609. If you are not planning on using them for racing, get yourself a tin of GRIP. Our local kart club allow us to use it on our karting tyres and it's great - the performance is not only better but the tyres last far longer as well. I won yesterday on tyres that we got in March last year and have done all 10 meetings since on them.
Thats a fair point guys about that stuff I had sort of blocked it from my mind but like you say karters know all about these tricks, I remember my brother showing me this years ago and then dropping the kart down to pull a burn out. Tyres were as sticky as hell after that. Rob I think I will try your idea first on a shakedown and see if I can't some life back into them.
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