R6 Message Net banner

1 - 13 of 13 Posts

·
Registered
Joined
·
2,011 Posts
Discussion Starter #1 (Edited)
I was reading this thread on clubracer.net and it had some interesting points. A trackside vendor (Motorace = Dave P.) is involved in a great disscussion about Heat cycles vs Tire life. I found it interesting and raises some questions about the validity of the statement "Tirewarmers increase tire life" made by tire warmer companies. This was also posted up by Motorace... an bulletin posted by Michelin that says "do not wrap PR series tires and let them air cool"

http://clubracer.net/forum/showthread.php?t=560

What do you guys think....

Personally, I have heard from some racers that I trust that tire warmers do not increase tire life. They are only really good for going "bonzai" into turn 1. I agree with the analogy of "if the brownies are done do you put them back in the oven?" because it makes som sense to me. However, the engineer in me says that if you can keep th etemperture constant it will last longer.....:umm :umm

I think it is time for Ulrich to do a comparrison of tire life w/ warmers in between eevry session and air cooling.
 

·
Fire Wrench Dammit!!!
Joined
·
3,322 Posts
Very good read..

As for what i think, i do not believe that tire warmers increase tire life AT ALL. You do not see them called tire life extenders, they are tire warmers. I know it may be stupid to say what something will do base on its name, but the simple fact is, its a tire warmer.

In all honesty, if they were that great and extended tire life, you would see every race team using them from motogp, to scca racing, to lemans.
 

·
Registered
Joined
·
193 Posts
the argument is about air cooling the tires. something I always do is when I'm done for the day or whatnot, I will put the warmers back on and let them warm for about five minutes, long enough for me to get out of my gear and then turn the warmers off and let them cool down that way. I can't give any technical data about why or why not, just that I read somewhere that letting the tires cool down this way is better than air cool. :umm
 

·
Registered
Joined
·
394 Posts
A tire warmers principle use is to make your tires hot for the first lap in a race. That is what they are designed for. Heat cycles (heating to operating temp then going back to ambient temperatures) affects the longevity of a tires useful life. The only time you really care is when you are trying to use the tire for more than one race or for practice. Most high level racers and motogp guys don't run tires into the ground like club level racers and privateers do. They demand much higher performance from a tire and they usually have tires provided so they have no reason to ride a tire until it has reduced grip.

In the course of a race day many club level racers will use the same tires for several races because the races are usually short. As each race goes by traction in the tires is reduced. Most will put the tire warmers on between close races to keep them at temp to reduce heat cycles and to prevent cold tearing. This alone will "extend the life" of a tire as opposed to just letting them cool between races.

After a certain number of heat cycles or laps the tire will loose grip no matter what you do. I think if you can reduce the number of heat cycles by leaving your tires warm in the short term, you can help keep the tire useful. Leaving them heated all day on a track day or race practice day seems to make little difference to me in the feel of the tire as oppose to heating the tire up before each outing. Usually by then I will be riding what the tires will allow, not riding what my skill level will allow.

Basically if you expect to keep doing your personal best lap times on a tire that is well used because you kept your tires warm all day, then you will be disappointed. Remember that race tires are not designed to give long life. They are designed to give maximum grip and handling for the duration of a race. That is why tire manufactures have "track day" tires which give very good performance for a longer period of time. They are affected less by heat cycles.

You could probably do more for the longevity of a tire by paying more attention to your tire pressures. This affects the operating temperatures on the track and the performance of the tire. I know lots of people check air pressures once a day, which is a mistake. I do the hot tire pressures myself to get the most of the tire.
It's no big secret...LoL. :rolleyes: Just ask your tire vendors and they can tell you what the optimal pressure and temperature should be for your tires when hot!

Your results may vary....
 

·
Registered
Joined
·
383 Posts
LeeNR6 said:
A tire warmers principle use is to make your tires hot for the first lap in a race. That is what they are designed for. Heat cycles (heating to operating temp then going back to ambient temperatures) affects the longevity of a tires useful life. The only time you really care is when you are trying to use the tire for more than one race or for practice. Most high level racers and motogp guys don't run tires into the ground like club level racers and privateers do. They demand much higher performance from a tire and they usually have tires provided so they have no reason to ride a tire until it has reduced grip.

In the course of a race day many club level racers will use the same tires for several races because the races are usually short. As each race goes by traction in the tires is reduced. Most will put the tire warmers on between close races to keep them at temp to reduce heat cycles and to prevent cold tearing. This alone will "extend the life" of a tire as opposed to just letting them cool between races.

After a certain number of heat cycles or laps the tire will loose grip no matter what you do. I think if you can reduce the number of heat cycles by leaving your tires warm in the short term, you can help keep the tire useful. Leaving them heated all day on a track day or race practice day seems to make little difference to me in the feel of the tire as oppose to heating the tire up before each outing. Usually by then I will be riding what the tires will allow, not riding what my skill level will allow.

Basically if you expect to keep doing your personal best lap times on a tire that is well used because you kept your tires warm all day, then you will be disappointed. Remember that race tires are not designed to give long life. They are designed to give maximum grip and handling for the duration of a race. That is why tire manufactures have "track day" tires which give very good performance for a longer period of time. They are affected less by heat cycles.

You could probably do more for the longevity of a tire by paying more attention to your tire pressures. This affects the operating temperatures on the track and the performance of the tire. I know lots of people check air pressures once a day, which is a mistake. I do the hot tire pressures myself to get the most of the tire.
It's no big secret...LoL. :rolleyes: Just ask your tire vendors and they can tell you what the optimal pressure and temperature should be for your tires when hot!

Your results may vary....
this I would call the 'minimize heat cycles' procedure, which most around these parts do as well. In addition to this, if there is a long break between races, guys will put the warmers on without heat to allow a slower cool down.

The AMA or GP guys dont ever run a tire more than one heat cycle, they just run a new pair so this doesnt apply to them.

I too am suprised by this statement from Michelin

:rtfm
 

·
Registered
Joined
·
648 Posts
Hold up!!!

Does that Michelin notice mean to run the Power Race Soft, Med/Soft, or Med at 28 PSI and not in the 22 PSI range?

I've been running the Power Race Medium rears at 21 PSI...
 

·
Registered
Joined
·
2,011 Posts
Discussion Starter #8
RayRevolver said:
Hold up!!!

Does that Michelin notice mean to run the Power Race Soft, Med/Soft, or Med at 28 PSI and not in the 22 PSI range?

I've been running the Power Race Medium rears at 21 PSI...

I thought the same thing when I whe I saw that. The way I read it is that the Pilot Power Race is run in the upper 20's or lower 30's and the PR series is the one that is run at 22 psi.
 

·
Fire Wrench Dammit!!!
Joined
·
3,322 Posts
brassballs1979 said:
I thought the same thing when I whe I saw that. The way I read it is that the Pilot Power Race is run in the upper 20's or lower 30's and the PR series is the one that is run at 22 psi.
That is correct.. Only the PR series are designed to be run at the lower psi..

Just a question to add, but what exactly is defined as a heat cycle, and when has a tire gotten cold enough to go through a heat cycle? I mean if all it has to do is cool say 20* for it to of gone through a heat cycle and the temp is over 200* while out on track, then keeping them in the warmers isnt actually doing anything, correct? Then #s are just hypothetical as i do not claim to know actual temps for any of this. Just saying, it does seem that there isnt a real clear definatino of a heat cycle and how exactly it affects the tire.

One other thing to add, during say pratice/qual do you see the guys come into the pits and have the warmers put back on as soon as they get in, or are they kept off?
 

·
Registered
Joined
·
383 Posts
FrkyMnky1487 said:
One other thing to add, during say pratice/qual do you see the guys come into the pits and have the warmers put back on as soon as they get in, or are they kept off?
GP or AMA guys will put new tires on.
 

·
Registered
Joined
·
394 Posts
FrkyMnky1487 said:
That is correct.. Only the PR series are designed to be run at the lower psi..

Just a question to add, but what exactly is defined as a heat cycle, and when has a tire gotten cold enough to go through a heat cycle? I mean if all it has to do is cool say 20* for it to of gone through a heat cycle and the temp is over 200* while out on track, then keeping them in the warmers isnt actually doing anything, correct? Then #s are just hypothetical as i do not claim to know actual temps for any of this. Just saying, it does seem that there isnt a real clear definatino of a heat cycle and how exactly it affects the tire.

One other thing to add, during say pratice/qual do you see the guys come into the pits and have the warmers put back on as soon as they get in, or are they kept off?
A heat cycle is one cycle of heating the tire to operating temperature and cooling the tire back to ambient temperatures. Most racers put the warmers on for a short period of time at maximum power (which I thought is like 185 degrees F on the CH's)to heat the tires before the first race. When they come in they will put on the warmers and set them on the lower setting (~135degreesF)until just before another race, then turn them up again. If it is really close together, they just leave them on high. Is that technically a heat cycle? Couldn't tell ya.

Some put the warmers on without power during practice and will just let them cool slowly. I have heard this is better for the tire, but I know no data concerning this. In my experience doing it either way I couldn't tell any difference. It's hard to say because the tire will have already had a heat cycle or two if you are at the point of using your warmers this way on the tires. If anything it may help conserve some heat in the carcass which will help speed up the heating process next time, especially on cold days.

Qualifying tires are worse than race tires about loosing grip quickly. They are only good for a few flying laps before they are toast. I don't know anyone who reuses them for practice or another qualifying session, so who cares?

The classic heat cycles (as I give a definition for them) does have a clear impact on tire grip. The more heat cycles you put on the tire the faster you loose grip. This is evident if you ever run an endurance race. The same tire you run for an hour or two in an endurance race (one long heat cycle)feels better and has better grip than the same tire after three short sprint races with three heat cycles (without warmers) and quite a few less laps.
 
1 - 13 of 13 Posts
Top