So Im doing my first track day at the end of the month. My front tire may not pass inspection. Center tread depth just touches Lincolns hair but does not cover it. Would it pass? Im not sure.
On the rear I have a spankin new Dunlop Q2 Sportmax.
So my brother is sending me a front gp tire.
I will have more grip on the front running a gp tire. Is this a dangerous move? Can I play with tire pressures to try and equalize the situation?
No cash at the moment for a new street front so these are my two options.
Run the used street tire or the slightly used gp tire?
Is the front the dunlop gpa 211? Honestly if it's your first track day I doubt you would even notice anything or push anywhere close to feeling the grips. I would say you're good to go.
I would run the q2's 33 cold. Never had experience with a gp tire. If it's the gpa I don't think you'll need tirewarmers but not sure on that.
Havent gotten it yet but it is a Dunlop for sure.
*Edit: yes it is a gpa 211.
http://www.dunlopracing.com/Pressures.pdf (http://www.dunlopracing.com/Pressures.pdf)
My concern would be low traction on the GPA. They are compounded for the track and warmer use. if you don't have a warmer for it, and can't keep heat in it (I'm assuming beginners group) it might be slipperier than you'd like.
You can probably mess with the pressure some, to help keep it warm- BUT not too much. Remember that if you run pressure too low, the bike will feel heavy in handling.
See if you can find out if they will have someone capable of doing tire changes at the track. A lot of times a local bike shop will come to track days for tires changes, suspension tweaks - drum up business etc. If there's the ability to get them changed at the track - roll out with your street tire on, and the GPA in your back pocket and see what they say. if they pass it, hurray. If not, then you loose a little time getting the wheel skinned, but you pass tech.
BTW - where are you going?
A used race tire is going to have a lot less grip than you might think, after some heat cycles the rubber goes south fast, so take it easy.
The Dunlop GP-A is a great tire, and will provide tons of grip, even a used one. They can be heat cycled quite a few times without any issue. A front race tire will last almost an entire season, so can go though many heat cycles without issue.
Like Slide said...my main concern would be getting heat into the tire, as race tires are slippery when cold. If you don't have warmers be sure to take it easy at first and brake as hard as possible to build up heat in them. Should be OK after a couple laps. As long as you're not riding like a total grandma I think you should be able to keep heat in them...just be sure to brake hard, as that's what gets heat into them.
Q2 on the rear and GP-A on front should be OK.
Thanks for the input all.
My bro is in the advanced class and im in beginner so I can use his warmers when he isnt. Think I will try the GP tire. Im pretty sure it will be fine.
We are going to the new NYST and registered through NESBA.
Cant wait.
Just got the tire today. Its in really good shape. Deepest tread area measures about 4mm.
Average tread depth on my street tire is about 2mm.
Sorry to dig up a somewhat old thread, but I'm wondering about pressures?
Any suggestions for my odd set up?
GPA 211 front
Dunlop Q2 rear
It's better this way than a far better rear than front. Pressure wise you don't want to drop street ones too much, but I'd probably work on about 30-32 in the front and 30 in the rear (cold). Pressures are a touchy subject though; on the track generally you want lower at the back for better footprint and also to get the tyres heating up more. IIRC, you'd want about 32-34psi hot in a gpa211, that's after sitting them in a warmer for 40 minutes-1 hour though; 30 psi cold is a ballpark to get you there. On the rear 30 is what I find is a good compromise with road tyres between extra contact patch and not too low that the tyre overheats or excessively deforms.
In terms of how much tread is left: that isn't always a good indicator of the level of grip available to a race tyre. As was mentioned before, the number of heat cycles it has been through is more of an indicator. The older the tyre, i.e. the more use it has had, the more it dries out and the harder it becomes, giving you less grip. I have at least 2 sets of tyres in the garage that half about half their wear left and yet they had lost quite a bit of outright grip due to the number of heat cycles they have been through.
Should be fine though. If you aren't running warmers you'll want to slowly bring the front in, i.e. don't expect to drop the bike on its side into the first corner, because you will actually drop it. The racier a tyre is, the more sensitive it is to heat. Braking is a good way to build heat into a front tyre - and within a lap to two laps it'll be up to temperature. So just build into it in the first couple of laps each session.
Thanks for the lengthy response. I was planning on all what you said with no warmers.
And I will try the suggested psi's. Since Im not "racing" I doubt I will have to fiddle with pressures much bit needed some kind of baseline to work from.
Thanks.