Warm Tire Pressure

[HAWK]

doesnt compressed air contain a high amount of moisture in it?  I thought that was the main point.  I really dont have a stake in this, just looking for accurate info.  I've got bigger issues than TP LOL

Compressed air will have moisture in it which will condense out as the temperature of the air goes down but line driers are very inexpensive and rather efficent and the other really big culprit is not draining the compressors tank daily.

[Sig]

I'll state this again.  Someone will have to tell me if I didn't say this, but...

Different manufacturers do different things.

Pirelli specifically states their hot tire pressures.  That is how you check them.  You'll have to have a basis of the heat in your tires from loading them up under traction to have any kind of basis for setting the tire pressure before you go out to ride.  Example, if a particular Pirelli tire requires 29psi hot, you're going to assume an increase in your tire pressure from cold.  Might be 3psi, might be 5psi. 

Michelin specifically states their cold tire pressures.  That is how you check them.  You'll check them cold, then you'll use the tire.

Methodology for checking tire pressures is derived from what the manufacturers find is effective for their carcass and compound.

I know that Michelin says to use cold temps. My point is, logically this cannot be consistent. Cold temp at VIR in March is a hell of a lot different than cold temp at Barber in August. With hot temps you can turn your warmers to whatever is recommended and set pressure accordingly.

Hot temps seem to make much more logic for a race tire. Maybe I'm just biased as a pirelli customer.

[Ducati23]

I never came to grips with the PR1/2 fronts.  The rounded profile was different than typical Michelin and feed back sucked compared to the previous Michelin fronts and the PRC. The PRC is worlds better and has the steeper more typical Michelin profile.

The PR3 is pretty short lived, but they are great one race tires. As Tom Mason says, Fresh is best! A PR5 will give "nearly" the same grip levels for much longer, its proven to be a true race all day tire. That said a new PR3 is magic when warm!  I have the digital tire bakers and heat the front/rear to 140/170.  30 psi in the PRC and 22 psi in the PR3 or PR5. 

[Super Dave]

There's a lot of myths about nitrogen out there and...

There are some race distribution points that use nitrogen almost exclusively.  It has a purpose, and the purpose is recognized as being useful in specific applications.

Yeah, nitrogen is most of what we breath, but there's more to it than that.  You'll have to contact the real tire engineering guys for the real specifics on it. 

[Sig]

I'll cut somebody a sweet deal on 500 cubic meters of 78% nitrogen air.

[Team_Serpent]

I'm sorry, just can't hold back from posting on this.

I believe the Michelin cold temp pressures given to club level racers is just an easy way to answer their customers question about what pressure to run.  Michelin probably has found that most of their customers can not or will not be able to consistently control Hot pressure and are more satisfied and have a more consistant tire performance when set to their recommended "cold" pressures.  If you think Michelin supported AMA and Moto GP teams are setting their tires at "cold" pressures then you are naive.

One thing that no one has mentioned yet is the tire's optimal operating temperature.  Air pressure is one of the things that effects the tire's operating temperature.  To really have optimum tire performance for your bike and riding style takes lots of testing and data collection.  Just because one combination is working for someone doesn't mean it will work for everyone.  This is why you hear all the talk during broadcasts about riders and their tire selection/decisions for the race when watching AMA or Moto GP.

Some things to think about when searching for optimal tire performance:

What is the outside temp and humidity?
What was the cold pressure?
What was the tire warmer temp set at?
What was the warm pressure after the tire warmers were on right before you went out for a session?
What is the pressure when I come off the track (and I don't mean after you pull into the pits after a cool down lap)?
What is the left side, right side and middle tire temperature when I come off the track?
What is the track temp?
What compound?
Type of track surface - abrasive, green, etc...
What is the riders feedback on tire performance and traction?

Take Notes!

[Toves33]

Taking notes will be key to finding a successful combination. You have some really good suggestions and I think I will use them to start my track notes. I didn't realize that people actually check the temperatures right after taking the tire warmers off and right after getting off the track. This is a good idea because I will always have a reference point to work off of whenever I am in doubt what my tire pressures should be. All I will need to do is refer to the notes. Thanks!