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Road Tyres Overheating & Performance?

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Hi Steve,

 

Recently I had a low side where I lost the front on a off camber left hander. I was running Metzeler M5 road tyres and had plenty of laps under my belt. Day was warm (20 degrees) and dry so the tyres were up to temp.

 

The tyres had been on the bike for 4-6 months and had plenty of tread left.

 

A comment was made to me that using road tyres on the track is not a good idea as they can overheat when a rider reaches a good pace, which then compromises performance (i.e. get greasy). Is there any truth to this or is it a myth?

 

To be honest I'm 99% sure it was me (weight on the bars etc...) which caused the loss of traction but thought I would ask anyway.

 

Thanks

Mike

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A very common problem, I don't know about Metzlers but my Michelin PIPO2CT (although they are very very good for streetriding) do the same thing, 2 rounds on Hockenheimring and you better take a break.

 

 

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Hi Steve,

 

Recently I had a low side where I lost the front on a off camber left hander. I was running Metzeler M5 road tyres and had plenty of laps under my belt. Day was warm (20 degrees) and dry so the tyres were up to temp.

 

The tyres had been on the bike for 4-6 months and had plenty of tread left.

 

A comment was made to me that using road tyres on the track is not a good idea as they can overheat when a rider reaches a good pace, which then compromises performance (i.e. get greasy). Is there any truth to this or is it a myth?

 

To be honest I'm 99% sure it was me (weight on the bars etc...) which caused the loss of traction but thought I would ask anyway.

 

Thanks

Mike

 

Overheating is something that you would visibly be able to see in a tire. the rubber gets so hot that it actually "Boils" and chucks of rubber will come off. This is seen ONLY at tracks known to have very high temperatures, like Daytona. If you overheated your tire (reguardless if it was a race tire or street tire), you would see chucks of rubber missing and the tire would be unusable.

 

Having said that; what you encountered was most likely YOU overriding the limits of that tire, not overheating. As a general rule, street tires are made NOT to overheat. A street tire will drop off in grip as it get to hot. Being hot and having less grip you cannot keep the same lap times, thus you will be going slower and producing less heat. So you will likely not ever overheat the tire on the sides (unless at tracks like Daytona). Its self correcting. But you can overheat a street tire in the center, by maintaining high speeds in a straight line. This would take many miles at +180MPH.

 

It sounds to me that you made a mistake in that corner, or its time to step up race tires.

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Mike,

 

A bit of pressure on the bars as you get going at a good pace can definitely effect the front end. Had a really good rider I know crash recently, he admitted he wasn't holding on with his legs enough, and did have too much on the bars.

 

If any lean angle got added with a touch of throttle at the same time, that'd be another thing to suspect.

 

Best,

CF

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Gonna add another public comment: Steve is an old friend, but the fact he comes up here and clears up the urban myths, well, I'm glad to have him--Steve if I haven't told you lately: you suck, but glad you are here. :D

 

Best,

Cobie

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Overheating is something that you would visibly be able to see in a tire. the rubber gets so hot that it actually "Boils" and chucks of rubber will come off. This is seen ONLY at tracks known to have very high temperatures, like Daytona. If you overheated your tire (reguardless if it was a race tire or street tire), you would see chucks of rubber missing and the tire would be unusable.

 

Having said that; what you encountered was most likely YOU overriding the limits of that tire, not overheating. As a general rule, street tires are made NOT to overheat. A street tire will drop off in grip as it get to hot. Being hot and having less grip you cannot keep the same lap times, thus you will be going slower and producing less heat. So you will likely not ever overheat the tire on the sides (unless at tracks like Daytona). Its self correcting. But you can overheat a street tire in the center, by maintaining high speeds in a straight line. This would take many miles at +180MPH.

 

It sounds to me that you made a mistake in that corner, or its time to step up race tires.

 

Thanks for the comments guys and clearing that up. Trying not to analyse it too much to be honest but the tyre was definantly not overheating going by Steve's description.

 

My thoughts are that it was a bit of both pressure on the bars with lean angle and that I over-rid the limits of the tyre. I was proably going the quickest I had ever been which led me to slip in terms of technqiue and also I'll be taking a good look at the tyres I'm using.

 

Cheers,

Mike

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Well, call it "overheat" or whatever, something does happen to streettires on racetracks after a couple of laps, no matter if there are bubbles or not

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Saying I'm fine with street tires doesn't mean much, as I'm a few seconds off-pace. I did, however, get to watch Jason Pridmore and Steve Rapp doing some fast times on stock GSXR 1000's running Q2's without any problems. They were sliding into corners and doing lap times that were competitive with the top local racers on modified bikes with slicks. I think if anyone would overheat street tires, it would be these two. No problems, though.

 

I don't race, so I use the street tires because they last longer than performance tires. I can get at least 8 trackdays on street tires running 10-15 seconds off the pace, and that's anywhere from Inde to Chuckwalla, to Auto Club Speedway. I can get up to speed in 2 laps and start pushing in 3.

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Well, call it "overheat" or whatever, something does happen to streettires on racetracks after a couple of laps, no matter if there are bubbles or not

 

 

+1 on this it seems like there must be more to this story - I have heard a lot about tires getting "greasy" or "going off", in regards to overheating, and have also heard of ruining a street-type tire by putting warmers on. Personally I had an experience some years ago on Michelin Pilot Powers on a REALLY hot day at Willow Springs big track - my rear tire got super slick and I brought it in to the tire guy who was on site - he told me my rear suspension was set way too stiff so my tire was having to do all the work of absorbing bumps and was flexing too much. He said the tire was getting so hot that when I leaned it over into a turn, the top layer of rubber was melted and sliding off, so it felt slick. I didn't see chunks of rubber missing, but the edges of the tire looked smeared and there were rolled up blobs of rubber hanging off the edges of the riding surface. It was one of my first track days and I was not riding very fast (bottom of the intermediate group, probably). He adjusted my suspension and tire pressures and the problem went away; the "smeared" looking rubber wore off quickly and the tire did fine after that.

 

Dunlop-RTS says:

"So you will likely not ever overheat the tire on the sides (unless at tracks like Daytona). Its self correcting. But you can overheat a street tire in the center, by maintaining high speeds in a straight line. This would take many miles at +180MPH."

 

 

I always thought the tire really did overheat, but I sure as heck wasn't going 180 mph. Was the other guy's assessment of the problem incorrect? Or does a bad suspension setup totally change the statement above, making the tire much more susceptible?

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Gonna add another public comment: Steve is an old friend, but the fact he comes up here and clears up the urban myths, well, I'm glad to have him--Steve if I haven't told you lately: you suck, but glad you are here. :D

 

Best,

Cobie

 

I couldn't agree more! Well...not the "you suck" part but the rest is spot on. Tires, or their overseas counterparts known as tyres (can I order those on eBay?) seem to have more urban myths than a freshman college dorm. Thanks for sharing you knowledge sir!

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Well, call it "overheat" or whatever, something does happen to streettires on racetracks after a couple of laps, no matter if there are bubbles or not

 

 

+1 on this it seems like there must be more to this story - I have heard a lot about tires getting "greasy" or "going off", in regards to overheating, and have also heard of ruining a street-type tire by putting warmers on. Personally I had an experience some years ago on Michelin Pilot Powers on a REALLY hot day at Willow Springs big track - my rear tire got super slick and I brought it in to the tire guy who was on site - he told me my rear suspension was set way too stiff so my tire was having to do all the work of absorbing bumps and was flexing too much. He said the tire was getting so hot that when I leaned it over into a turn, the top layer of rubber was melted and sliding off, so it felt slick. I didn't see chunks of rubber missing, but the edges of the tire looked smeared and there were rolled up blobs of rubber hanging off the edges of the riding surface. It was one of my first track days and I was not riding very fast (bottom of the intermediate group, probably). He adjusted my suspension and tire pressures and the problem went away; the "smeared" looking rubber wore off quickly and the tire did fine after that.

 

Dunlop-RTS says:

"So you will likely not ever overheat the tire on the sides (unless at tracks like Daytona). Its self correcting. But you can overheat a street tire in the center, by maintaining high speeds in a straight line. This would take many miles at +180MPH."

 

 

I always thought the tire really did overheat, but I sure as heck wasn't going 180 mph. Was the other guy's assessment of the problem incorrect? Or does a bad suspension setup totally change the statement above, making the tire much more susceptible?

 

Hotfoot,

 

Let me shed my take on it:

 

Your statement "I have heard a lot about tires getting "greasy" or "going off", in regards to overheating, and have also heard of ruining a street-type tire by putting warmers on." Has a lot of "I have heard" in it. this is were myths come from. This is not from fact, but more from someone trying to figure something out, then telling another, then telling another and soon the story gets out of hand. So forget what you "Heard".

 

Now lets look at your personal encounter with a setup issue you had. Clearly the issue was suspension. The tire guy was able to help you out and resolve the problem. The tire did not overheat, or chunk. it just did not work at that suspension setting. you made a suspension change and it then worked. if the tire had truly overheated it would not be usable. since you could continue with the tire then it was the suspension. try not to assume the tire overheated when in fact it was suspension. poor suspension can make the tire look very odd, and I can see how one might call it overheating for lack of any other explanation. But overheating in this situation was not the issue. It is possible some people define "overheating" differently than I, but from my position, overheating is the rubber chunking. And YES a bad setup can make the tire do odd things and makes the tire more selectable to issues.

 

Note Jason's observation that very fast riders like Pridmore and Rapp, went very fast on Q2. this is proof that these issues are rider and suspension more than anything else.

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That's really good info. Good to know that it's not actually overheating, losing grip so it doesn't overheat & chunk out makes sense.

 

But are road tyres really so bad these days? I have been using Michelin Power Pure for a little bit, the breakdown for them is something like 85% road and 15% track use. But I guess you get used to the way they work because I managed to move up a group while using them and my very last track day had the two fastest groups combined (I'm usually in 2nd fastest group) and pretty much the only guys who were completely breezing by were on Ducatis with slicks (they were going by mid-corner, especially on a tricky part where it's over a crest and tightens up alot). I guess it depends alot on the track, but I started to work more on taking lines where I'm not leaned over so much and getting a better drive onto the straight and noticed that I was going faster, I'm sure I can go faster still on these tyres. I like the idea of using a lesser tyre to it's maximum before moving to a full-on sports tyre so I'm planning to keep using Power Pures for a while yet. The front always feels great to me, never had it slide yet, all the while I'm still amazing myself with just how much speed you can carry into a corner and how quickly it's possible to turn in. The rear I've noticed does have a tendency to slip right as I'm initially trying to get on the throttle, but it's no biggie since it stops slipping as the bike straightens up and I just keep winding on the power and continue as usual.

 

I've gotta wonder if alot of people just get spooked by the feel of a tyre slipping under acceleration, especially if the bike is leaned over, and then get scared away from using street tyres on the track? I figure that if you're aware of the limitations and expect a certain amount of slipping & sliding you can just ride accordingly. It definitely hasn't felt dangerous to me, it's all perfectly predictable and controllable (unless you're getting greedy with the throttle, in which case no tyre will be able to help, right?) Unless I have the completely wrong idea and a good tyre should feel rock-solid planted 100% of the time?

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That's really good info. Good to know that it's not actually overheating, losing grip so it doesn't overheat & chunk out makes sense.

 

But are road tyres really so bad these days?

 

 

I've gotta wonder if alot of people just get spooked by the feel of a tyre slipping under acceleration, especially if the bike is leaned over, and then get scared away from using street tyres on the track? I figure that if you're aware of the limitations and expect a certain amount of slipping & sliding you can just ride accordingly. It definitely hasn't felt dangerous to me, it's all perfectly predictable and controllable (unless you're getting greedy with the throttle, in which case no tyre will be able to help, right?) Unless I have the completely wrong idea and a good tyre should feel rock-solid planted 100% of the time?

 

Current performance sport tires are really quite good. Note the Q2 and Jason's first hand acount of how fast a top rider can go on Q2. I can't speak for other brands of street tires, but I can say the Q2 is top of the line for performance street riding and track days.

 

Riders also should not discount the performance increase of using the race product, like D211GP-A. These will have even more grip. All while still being usable for the street if needed. The myths about race tires being unusable on the street are just that, a myth. I use them all the time, in fact I rode my Bandit 1200 for 6,000 miles across the USA this summer and used D211GP-A (they were even used on the track before I put them on). They worked great and I never slipped a bit, in all conditions, even rain.

 

Should a tire be 100% planted? Certainly that would be nice, but we don't live in the push button world of video games while on the track. Top riders slide and move the bike around at top lap times, its just the way it works. If you use the same tire and go much slower, certainly it will feel like its 100% rock solid, but is that what you come to the track for? No, you come to push as hard as you can, and that entails pushing and possibly sliding. Its the game we play.

 

There are many gains to be had with suspension and also with rider training. There is only so much the suspension guy and the tire can do, TRAINING will enhance you ability to ride and understand what you are feeling on the bike. I can't count the times riders tried to explain a problem and attributed it to this or that on the mechanical side (tires, bike, shocks...) but I well knew the guy just did not know what he was feeling or how to understand what was going on. I must highly recommend EVERYONE here keep advancing in the learning curve of riding.

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Clearly the issue was suspension.

It just did not work at that suspension setting.

You made a suspension change and it then worked.

... since you could continue with the tire then it was the suspension.

... in fact it was suspension.

Poor suspension can make the tire look very odd,

... these issues are rider and suspension more than anything else.

 

Man was I wrapped up on the tires themselves. Hand in hand. Suspension and tires. Suspension and tires. Now, repeat this 1,000 times.

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If you are asking about my specific example, it wasn't related to heat cycles, brand new tires and I was having problems within just a few sessions.

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