Nitrogen experiment

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Originally Posted by mark niemi

just put your head in the oven. that's probably what mitch is considering.

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Hey hey hey, I already admitted I was retarded, now I have to cook my poor broken brain? Brutal!

Can't buy entertainment like this.

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Originally Posted by Mitch Williams

Both of those ideas were proven to be untrue. "Lewis's Law"

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I like the sound of that. And you're absolutely right about my pressures, thanks for the lesson, much appreciated.

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Originally Posted by Kasey Lewis

Would 4-6 be normal for cold to off track? They always seem to be hot. Temp gun said they were close, but I only check randomly with the gun.

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There's something here that lends to the answer under contention... Not sure what it is... ;)

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Originally Posted by Tom Anderson

There's something here that lends to the answer under contention... Not sure what it is... ;)

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Yeah, I actually read that after I typed it....duh. Never claimed I was particularly bright

If you're going Mythbusters on this problem, don't forget to tape blowing something up at the bomb range or at least your backyard. ;)

And by tape, I mean record. And by record, I mean video. And by video, I mean GoPro®.

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Originally Posted by Sean Gurevich

If you're going Mythbusters on this problem, don't forget to tape blowing something up at the bomb range or at least your backyard. ;)

And by tape, I mean record. And by record, I mean video. And by video, I mean GoPro®.

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I figured they would find what pressure the tire would explode at!

Tires should normally grow by at least 6 pounds on tires warmers with "conventional air". Normally 10 degrees F makes 1lbs difference in air pressure. In our case we warm our tires to 210 degrees F (rear) and about 170 degrees F (Front). So if the air temp was 85 degrees when we set initial pressure, then the rear will grow about 12.5lbs in pressure. This is based on the ENTIRE tire being properly warmed up. We have found that the rims will get about 135 degrees F when the tires are “completely warm”. We adjust according when the temps/pressures don’t match up. Usually through the weekend we keep track of small changes/nuances of tire temps to get optimum performance. We use the temps as we have found that we get minimal growth in tire pressure with Danny's riding. Using this process we see about 2-3 pounds of growth in the rear Pirelli tire and the front normally stays the same pressure…maybe +1 pound growth.

With different tires, we see different temp performance. We have found in the AMA with the control tire that we get a higher growth. The specific reason for this is the sidewalls and casing are thicker and create more heat (which means pressure) than other tires in the paddock. Our solution was to put the warmers on for an hour and a half before we used them. We also put blankets on top of the tires (despite the fact that the air temp was nearly 100 degrees). This put the rims at temps around 150lbs. Using this process, we saw only 2 pounds of growth in the rear tire and the front normally stayed the same pressure.

We have used Nitrogen to see what the “difference would be”. The issue is that you never get a “laboratory environment”. You will always have moisture in the tire from the lube/soap & water from the tire mounting among other things. We did not notice any significant changes in tire pressure growth. Moisture (water) content is what creates the growth in pressure relative to heat. We noticed MAYBE 1lbs-2lbs less tire growth. It was not a huge difference. We did see a little less growth when we did not have the temp all the way up and had to figure in pressure growth.

To run your best, tire pressure is critical. You can run 2-3 seconds off the “hot pace” without a solid tire pressure setup if you are a good rider. You can even put in a fast lap or two that will match that “hot pace”. At the same time, many riders don’t give themselves a chance to get optimum performance because they practice on tires that are too shagged to run a pace to replicate the type of performance they should expect…and get to that optimum setup.

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Originally Posted by marcus mcbain

Tires should normally grow by at least 6 pounds on tires warmers with "conventional air". Normally 10 degrees F makes 1lbs difference in air pressure. In our case we warm our tires to 210 degrees F (rear) and about 170 degrees F (Front). So if the air temp was 85 degrees when we set initial pressure, then the rear will grow about 12.5lbs in pressure. This is based on the ENTIRE tire being properly warmed up. We have found that the rims will get about 135 degrees F when the tires are “completely warm”. We adjust according when the temps/pressures don’t match up. Usually through the weekend we keep track of small changes/nuances of tire temps to get optimum performance. We use the temps as we have found that we get minimal growth in tire pressure with Danny's riding. Using this process we see about 2-3 pounds of growth in the rear Pirelli tire and the front normally stays the same pressure…maybe +1 pound growth.

With different tires, we see different temp performance. We have found in the AMA with the control tire that we get a higher growth. The specific reason for this is the sidewalls and casing are thicker and create more heat (which means pressure) than other tires in the paddock. Our solution was to put the warmers on for an hour and a half before we used them. We also put blankets on top of the tires (despite the fact that the air temp was nearly 100 degrees). This put the rims at temps around 150lbs. Using this process, we saw only 2 pounds of growth in the rear tire and the front normally stayed the same pressure.

We have used Nitrogen to see what the “difference would be”. The issue is that you never get a “laboratory environment”. You will always have moisture in the tire from the lube/soap & water from the tire mounting among other things. We did not notice any significant changes in tire pressure growth. Moisture (water) content is what creates the growth in pressure relative to heat. We noticed MAYBE 1lbs-2lbs less tire growth. It was not a huge difference. We did see a little less growth when we did not have the temp all the way up and had to figure in pressure growth.

To run your best, tire pressure is critical. You can run 2-3 seconds off the “hot pace” without a solid tire pressure setup if you are a good rider. You can even put in a fast lap or two that will match that “hot pace”. At the same time, many riders don’t give themselves a chance to get optimum performance because they practice on tires that are too shagged to run a pace to replicate the type of performance they should expect…and get to that optimum setup.

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That's a great answer! Thanks a bunch.

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Originally Posted by marcus mcbain

Tires should normally grow by at least 6 pounds on tires warmers with "conventional air". Normally 10 degrees F makes 1lbs difference in air pressure. In our case we warm our tires to 210 degrees F (rear) and about 170 degrees F (Front). So if the air temp was 85 degrees when we set initial pressure, then the rear will grow about 12.5lbs in pressure. This is based on the ENTIRE tire being properly warmed up. We have found that the rims will get about 135 degrees F when the tires are “completely warm”. We adjust according when the temps/pressures don’t match up. Usually through the weekend we keep track of small changes/nuances of tire temps to get optimum performance. We use the temps as we have found that we get minimal growth in tire pressure with Danny's riding. Using this process we see about 2-3 pounds of growth in the rear Pirelli tire and the front normally stays the same pressure…maybe +1 pound growth.

With different tires, we see different temp performance. We have found in the AMA with the control tire that we get a higher growth. The specific reason for this is the sidewalls and casing are thicker and create more heat (which means pressure) than other tires in the paddock. Our solution was to put the warmers on for an hour and a half before we used them. We also put blankets on top of the tires (despite the fact that the air temp was nearly 100 degrees). This put the rims at temps around 150lbs. Using this process, we saw only 2 pounds of growth in the rear tire and the front normally stayed the same pressure.

We have used Nitrogen to see what the “difference would be”. The issue is that you never get a “laboratory environment”. You will always have moisture in the tire from the lube/soap & water from the tire mounting among other things. We did not notice any significant changes in tire pressure growth. Moisture (water) content is what creates the growth in pressure relative to heat. We noticed MAYBE 1lbs-2lbs less tire growth. It was not a huge difference. We did see a little less growth when we did not have the temp all the way up and had to figure in pressure growth.

To run your best, tire pressure is critical. You can run 2-3 seconds off the “hot pace” without a solid tire pressure setup if you are a good rider. You can even put in a fast lap or two that will match that “hot pace”. At the same time, many riders don’t give themselves a chance to get optimum performance because they practice on tires that are too shagged to run a pace to replicate the type of performance they should expect…and get to that optimum setup.

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wouldn't this in itself create a higher pressure since the tires will not "grow" as much...?
it also seems that the best way to setup pressure is if you know what kind of temp YOU'RE putting on the tire while riding at pace,then heat the tire to that temp while you set the pressure.
and holy crap, 210* ! can mere mortals get the tire this hot ON track?

when i shoot my tires with my pyrometer, i find that the temps vary quite a bit from where the element sat to the mid point of the next one.... chicken hawk multi temp..

The Nitrogen is a waste of time and money. All you need is to drain your air compressor daily and have a descent water separator.