optimum tire temperature data?

[i-Zapp]

I admittedly have not paid much attention to my tire pressure - primarily because I just haven't understood HOW to know when to make adjustments. Guys talk about making 1 psi adjustments to dial in their tires, but honestly I think it's a stretch for a weekend trackday rider like me to notice such a subtle difference in the actual performance of the bike (was it the tire that made the difference in the lap time, or was it just me figuring out the track...).

I gotta believe every performance tire was probably tested on a fancy test rig that determined at what TEMPERATURE (not pressure) it achieves its maximum grip. The job of the rider/crew is then to get the tire into that sweet spot, which would occur from a combination of the rider working the tire on track, and from flexing/deformation. This last part is where the rider has some control over the tire temperature - less pressure = more flex = more temp.

The question becomes "how do you know when you're in that sweet spot???". You can INFER the temp by looking at the wear, or by feeling it, or even by estimating the temperature by how much the pressure went up (seems flawed). But wouldn't the best method be to actually MEASURE it? I realize that it requires a special pyrometer but isn't that the right way to do it? And if so, do the tire companies publish their intended/optimum temperature ranges?



I haven't found anyone that does. Is it because they don't trust non professionals to do it correctly, or is there something proprietary about the info? Or is there something inherently dangerous about it?

 

[jtdbsr]

I'm not an expert by any means, however, looking at the tires after each session and checking the wear patterns is a good place to start IMHO. If tire wear looks good, temperature and pressure is where they should be. Two weeks ago I cleaned up hot tearing by raising the off warmers pressure by 2Psi. I also have a infrared pyrometer from Home Depot that seems to be pretty accurate.

 

[i-Zapp]

Crazy - I used Dunlop's website form and actually got a REPLY!

From Dunlop:

Measured with a probe. ideal temp range for Q3’s would be…
Front tire: 120-180F
Rear tire: 140-190F

Regards,
Consumer Affairs, Motorcycle
Goodyear Dunlop Tires North America, Ltd.200 Innovation Way, Akron, OH 44316
​

It's a pretty wide range, but targeting the mid-range temp would probably be optimum: 150F front, 165F rear

Keep in mind, these temps are for use with the type of pyrometer that inserts in the rubber of the tire. Surface temps measured with an infrared gun are going to be lower (the actual tire temp will be higher than you think).

 

[D-Zum]

Pressure and Temperature are inter-related when it comes to tires. Tires need heat to provide grip/adhesion to the road surface. This is generated by the flexing of the tire's carcass.
(under braking for the front, under acceleration for the rear). If you're tires have too much air in them, then the carcass will not flex enough and your tires will not get up to the
desired operating temperatures.

Desired meaning the temperatures/environment for which the tire maker designed the over all tire system to work correctly.

Deviation either way (too hot or too cold) will result in unnecessary wear, degraded performance, and a bigger hole in your wallet because you will
have to buy more tires than you would have needed to IF you had maintained the proper temperature/pressure/heat balance the tires need.

I had tire wear issues about 5 years ago, and spent $2,000 on tires in one year to do 16 track days.

The next year, I got my suspension changed to Ohlins, had it properly setup, and ran Dunlop Slicks and spent $1,000 or maybe less on tires to do 16 days.

I don't notice it so much with fronts, but I can tell with rears if I'm over inflated now. I'll go out and the bike steers a little "funny"..doesn't feel quite as planted as I'd like mid-corner. When I come in I'll check the pressures right off the track..and sure enough..the rear will be 24 or 25 psi versus the recommended 23 rear. Bleed off to 23 and for the remainder of the day, all is well.

 

[Mikey75702]

If you look at some of Dave Moss' videos on youtube (or even the DVD he had out a while back), he tries to explain some of the issues with tires and how to read/fix them. He shows you different suspension problems, and even different air pressure problems. In one of the video's he even suggests that some tires may be sensitive to as little a 1/2 psi. As for my feelings of differences in the tire, at my skill level I cannot feel a difference while riding. I just notice a difference in my wallet if I don't keep up with the tire pressures.

 

[steftoff]

Here is a question for you tire guys.
I am currently running Pilot power front and pilot power 2ct rear. My bike is a 2000 F4 totally stock except for the exhaust can. I am in the I group mid pack level skillz. What psi do you recommend as a start cold/hot? I do NOT have warmers.
The last couple TD's I have been running 28front 25rear (hot) right off the track. There doesn't seem to be any funny wear and they seem to stick ok am I close or way out of line?

 

[Greg ZX6R]

Here is a question for you tire guys.
I am currently running Pilot power front and pilot power 2ct rear. My bike is a 2000 F4 totally stock except for the exhaust can. I am in the I group mid pack level skillz. What psi do you recommend as a start cold/hot? I do NOT have warmers.
The last couple TD's I have been running 28front 25rear (hot) right off the track. There doesn't seem to be any funny wear and they seem to stick ok am I close or way out of line?

I believe Michelin calls for 30 psi front (cold) and 28 psi rear (cold) for their street tires.

 

[steftoff]

I believe Michelin calls for 30 psi front (cold) and 28 psi rear (cold) for their street tires.

That was what I had heard. U started running those temps but they just didn't feel planted in the corners so I started playing around with pressures. Do you know what the absolute lowest psi would be? Or is it trial and error? I errored on the highside last year and it cost me big time... (I crashed) don't want to do that again...lol

Stefan

 

[Mikey75702]

That was what I had heard. U started running those temps but they just didn't feel planted in the corners so I started playing around with pressures. Do you know what the absolute lowest psi would be? Or is it trial and error? I errored on the highside last year and it cost me big time... (I crashed) don't want to do that again...lol

Stefan

If the tires are wearing well and you like the way they feel, I would say its probably ok.... But since you posted HOT pressures... Your cold pressures are probably somewhere in the neighborhood of 24-25 psi Front and 21-23 psi Rear... I probably wouldn't go any lower than that.

 

[D-Zum]

Don't guess....call the tire supplier/vendor adn get their recommendations.

For Michelins: Walt Schaefer Enterprises: (256) 538-5906

For Dunlop:

Race Tire Service
National Distributor
3026 Owen Drive #111
Nashville, TN 37013
Orders: (800) 772-8473
Technical: (615) 641-3323
Fax: (615) 641-8959
info@dunlopracing.com
www.dunlopracing.com

 

[steftoff]

Thanks D...

Stefan

 

[Rapid Ron]

That was what I had heard. U started running those temps but they just didn't feel planted in the corners so I started playing around with pressures. Do you know what the absolute lowest psi would be? Or is it trial and error? I errored on the highside last year and it cost me big time... (I crashed) don't want to do that again...lol

Stefan

On one Dave Moss segment an Aprilla 1000 rider had his tire pressures at 18PSI (yes 18 ! ). Seems low but it worked for the guy and Dave Moss congratulated him on his speed. I do track days on a lightweight bike and in order to get heat in the tire I am also running 18.