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Just curious...what makes the front tire on a motorcycle wear like that? I guess you call it cupping. If it was on my car I would say the front end needs an alignment. I can understand the odd wear patterns on a car where there are adjustments on several different axes. I've only had four bikes but I've never noticed the phenomenon on any of my other bikes.
 

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that used to happen on my '74 bmw. i'm not 100% sure but i think that is a suspension issue.

dog
drowning in the land-o-squids
 

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It's caused by the way the tire is pulled back resisting traction while breaking in the turns. You can cup the rear the same way by acceleration hard while leaned over.
lower than normal air pressure will exacerbate the cupping.

 

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I was national sales mgr. and product specialist for Avon M/C tires for 15 years and have seen this allot. This ramp type wear is caused mainly on front tires because they are put under the stress that cause this during breaking. Rear tires get it from a different set of factors and the acceleration force cancels the breaking wear effect. What happens on the front tire is best illustrated if you think of an old block tread pattern tires. The "heel and toe" wear, as it is referred to, is created when you apply the binders. The stress is put on the leading edge of the block (the heel) and this energy is transferred along the block until it get to the trailing edge (the toe). When it gets to the end of the block this edge "lays down" in the rain groove. As it rolls past the edge it flips up having released all the energy and creates a high side of the block. It is very much like your feet when you walk. First you heel strikes the ground and at the end of the step your toes turn up, except the tire block doesn't have muscles to return it to the normal position. Modern sport tires rarely show this because the tread is shallow and the grooves are at angles that try to follow the stresses verses running at 90 degrees to the stress. Hope this helps.
 

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I question the notion that the cause of front tire cupping is braking in turns. I think I've had a cupping problem on just about every front tire I've ever had, on every motorcycle, and I never brake in turns. My cornering style is yer basic MSF style: brake before the turn and get off the brakes as I look and lean, then roll on the throttle all the way through the turn.

I'm also pretty careful about front tire pressures, always keeping them at the mfgr. recommendations for the bike. Could suspension set up have something to do with it? I'm pretty ignorant when it comes to suspension seet up, but I don't have any handling problems with my TT and it still cupped the front BT-010 slightly.

-KeithU
 
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