tire pressure?

Many theories.

Someone correct me or expand on this, but I would contact the tire manufacturer and ask them what they suggest for use of that tire on the track. If it feels to "mushy" add a pound and see. You have to find what works for your type of riding.

 

are those "dun-pops"?

generally (repeat GENERALLY) a good starting pressure for street/track tires is 30/30. You then work up or down from there. i don't know how experienced you are on the track, but most riders never "feel" a tire when in operation. they usually feel the change in the suspension and confuse mushy with compression and rebound. obviously riding on the street doesn't work the suspension the same as on the track. the mushy feeling may be the suspension working in a manner you may not be used to. Q:does the mushy feeling happen when accelerating out of a corner (leaned but transitioning)?

 

FWIW, I ran the qualifiers that came on my 06 R6 for a couple track days before i went to race tires. I ran 30/30 with absolutely no problems. I second starting there.

 

I agree with the Keystone cops up above... 30/30 for the track, 36/36 sounds fine for the street. typically, the harder the preassure, the longer the tire will wear, but the less grip they'll prvide. you shouldn't need all the grip that the tires will give riding on the street so there's no need to drop the pressures any lower. you're not breaking any laws now, are you? :roll:

 

Now that's funny, I don't care who you are! :lol:

Anyway, I ran 30/30 with 2CT's last year, and had no issues.

Since I am somewhat new to track days, I have to purposely remember to check the pressure before and during the track day. That is where my new track day list will come in very useful.

 

30/30 on Michelin Pilot Powers on the track...knee draggin fun. 32/34 on the street for me.(unless I'm feelin saucy!)

 

FWIW, I run 2CTs on the track as well so I contacted the Michellin Man himself; he said 30F/28R cold psi was recommended for track day usage.

 

It is my understanding that the lower the pressure, the more the tire carcass flexes and the more heat it will build. At 42lbs without a serious amount of weight on the bike the carcass is not going to flex and you are not going to get heat into the tire, which means you will not have much traction.

As the temperature increases so does the tire pressure. To me, this means that starting at a lower pressure will probably get you close to the same pressure as running a higher pressure once the tire comes up to operating temp.

With the temp up you heat cycle the tire harder and you lay more rubber on the track, thus the tire doesn't last as long.

As a track day rider or club racer you are going to be better off going with slightly lower pressure then slightly higher pressure because you will get more traction.

I don't know about you, but on the track I will give up traction for tire wear any day.

just my $.02

Chad

 

I just got a new SV with a set of Dunlop 209s on it. this is my first set of race tires and first of Dunlops. 30/30 on these???

 

Yes, perhaps a bit lower on the rear to start. 28-33 front, 26-28 rear.

http://www.dunlopracing.com/fitment.htm

scan to the bottom and look for SMAXGP.

 

thanks

 

blue?

why are the edges of my tires turning blue??

 

is that a serious question?

 

Yes sure is. The tires are Perelli pros. I used them for 2 track days at little talladega. Ive never had tires do this to me before. are they toast?

 

The blueing is caused by the tires chemical compounds migrating to the surface and cooking off from the heating then cooling cycles. I take it you're not using tire warmers? for more info, follow the link in my signature.
Cheers,
Lance

 

ah i see

you are right (i had not been using warmers) my generator broke and i had not been using my warmers those days. Along with the blue strips, the tires seem to be slightly harder to the touch. like a chewed up plastic feel and i suppose this related to the heat cycleing too.

this past weekend at Barber I had my warmers cooking on a different bike with different tires in between sessions. the tires on this bike display no blueing and are in great shape.

Now, here is another question:
It was damn hot last weekend even in the shade. When it is punishing hot like this how do you keep the tires from getting too hot and losing traction?

 

The hardness is from the heat cycling- they very well may be cooked. As far as concerns about tires oveheating, compound choice is key. I've found street tires get greasy over 85; med compound race tires are sketchy under 65, esp w/o warmers. Too soft of a compound will overheat and wear really fast. Mediums seem to be the best compromise for trackdays, IMHO.
Lance

 

Stick-er Shock

Thanks for the link. I am definately one to take a lap or two to heat up my tires since I don't have warmers. It's a preventative measure I was comfortable with, but never considered it from the long term COST perspective.

Comparing the cost of additional tires vs. the one time expense for warmers....guess warmers are on the list.

Thanks for the link.