Tire Warmers

[rchase]

I recently had an experience with tire warmers that I wanted to share. I went to a track day in December and the outside temps barely got into the 60's all day and most of the time it was in the mid 50's. I have had some great experiences in the past with warmers but I suddenly realized the shortcomings after the cold time I spent at the track.

 

My bike is a BMW S1000RR on Dunlop Q3's. I typically run a hot pressure of 31 front 26 rear. My warmers are set to 160F. For the cold I set the pressure to 34 and 28 hot because the cooling effect from going from 160 down would reduce the pressure lower than I wanted. I asked a few experienced people about the pressure because of the cold temps. Their advice was odd but made sense. I'm glad I went with it even if I don't fully understand.

 

What was most shocking to me is how quickly the tires cooled off. When I returned from most of the sessions I was seeing temps in between 65F and 73F. This was an unscientific test of course since I was using the temps off of the warmers themselves but it was a surprise that the tires were unable to hold a good temperature.

 

Overall I'm an average rider and not one of the "fast guys". I use warmers not out of need but for an extra margin of safety. In a normal temperature environment warmers might be a slight pain but they provide some great peace of mind knowing the tires are "as hot as they can be" right away. They don't stay that way though if it's cold out.

[FieryRobot]

Yeah, our track providers out here warn everyone on the cold days about this. You might think you have all the grip in the world the first couple of laps, but it's downhill from there.

[tmckeen]

RChase,

 

I'm pretty sure your method of checking your tire temps after a session is, at best, wildly inaccurate. If your using the temp indication on the tire warmers them selves, they have been sitting in your pit, off and basically cooled down to the ambient temperature, and just putting them back on the tires isn't going to transfer enough heat from the rubber itself to wherever the sensor in your tire warmer's is to give you a accurate temperature. Get yourself a cheap IR thermometer and check the tire with that when you pit in.

[rchase]

Oh yes. I'll admit it's not accurate at all. Just the comparison between the temps that I saw previously with the warmers when they were first plugged in vs this time was shocking for me.

 

That's actually a pretty good idea though. I even have a laser thermometer in my tool box. Next time I'll have to do an experiment. Leave the thermometer on the pit wall and take a reading "right off" the track. But that will have to wait until next year unless I luck out on a private day before spring.

[benhamf15]

Robert,

When you check them, do so in the middle and on each side. The temperatures will very likely be different for all three readings. Let us know what you learn.

 

Benny

[rchase]

Benny. Will do for sure! Might be a while but I'm quite curious myself. If I had to guess based on the track I was riding with mostly right hand turns the center would be the warmest followed by the right hand side and the coldest side would be the left.

[tmckeen]

So I did my own very unscientific test this morning

 

My morning commute the temps were in the low to mid 60's, Q3's at 38 and 40 psi, after 35 or so miles of freeway, a few stop lights and a mile or two of surface streets when I arrived at work my tires were still warm to the touch, so I'm pretty sure the temps you listed for coming in off the track are WAY!!! off.

[rchase]

That's pretty unscientific. Lets punch some holes for some fun.

 

On your commute were you doing 150mph+ down the expressway then hard on the brakes into a sharp corner?

The cold blast of air down the straight was pretty brutal. Towards the end of the sessions I was short shifting just to stay warm. I suspect a LOT of the cooling happened on the straight at least that's where most of the cooling was happening to me.

 

I'm actually pretty curious now so I'll haul out the thermometer next time.

 

Here's something interesting as well. A wind chill chart. It does not go up to 150mph though.

 

[tmckeen]

I'm sure your familiar with what actually generates the heat in your tires, which is carcass flex

 

My point was that if after nothing but 80 mpg straight line travel, moderate braking and no hard cornering at tire pressures that limit carcass deformation to a minimum my tires were still warm to the touch, the idea that yours would be 65-73° after a track session that included hard braking and sharp corners seems off,

 

Personally I'd be curious at profiling the actual temperature of your tire compared to what the temp display on your warmers claim's to be. I did this with mine when I first got them, and while they don't have a temp display the uniformity and temperature was not the even perfect 170° I was hoping for

[rchase]

Certainly more questions than answers. That we can probably both agree on.