Uneven Front Tire Wear - 06 zx10

[zx10x2]

I have have this problem for a while. The front tire is wearing uneven. If you look at the groove, the rubber on the inside is higher than the rubber on the outside of the groove all the way around the tire. If I rub my finger along the center of the tire I can feel humps. Over time the uneven wear and humps can be seen with the naked eye.

I talk with my mechanic who has a shop and also races motorcycles told me its the tires pressure. After he told me that I checked tire pressure when I ride and I still have the problem. I have tried all different tire pressures (34, 36, 38). He recommended 38 for street riding. The new tire I put on in October has 400 miles on it and its starting to do the same thing.

Wheel is balanced good. Oh when I am riding on the highway if I disengage the clutch and let it coast the front end vibrates. I checked the forks to make sure they are equal lenngth and adjusted the same and they are. Any suggestions.

[hs1113]

Are you sure the triples aren't tweaked or does the frame have any damage? Maybe the axle itself is tweaked or tightened wrong? Just trying to suggest things that could be wrong without really noticing.

[bgmagma10]

Originally Posted by hs1113

Are you sure the triples aren't tweaked or does the frame have any damage? Maybe the axle itself is tweaked or tightened wrong? Just trying to suggest things that could be wrong without really noticing.

Thats what I was thinkin. Check whole front end, check if forks are same height, and nothing is bent, and it sucks but may try changing steering stem bearings as well..

[SkyDork]

Sounds like cupping to me. It's caused by the front tire squashing down under braking and the tread blocks wearing unevenly as the tire deforms. Yes, this is typically caused by running lower tire pressures and exasperating the wear. But certain tires will exhibit this more than others. What type of tires are you running?

[bgmagma10]

Originally Posted by SkyDork

Sounds like cupping to me. It's caused by the front tire squashing down under braking and the tread blocks wearing unevenly as the tire deforms. Yes, this is typically caused by running lower tire pressures and exasperating the wear. But certain tires will exhibit this more than others. What type of tires are you running?

Thats kinda what I was thinkin too until he said he put a new tire on and its doin the same...

[SkyDork]

CUPPING:
Cupping, which is more accurately described as scalloping (see pictures, but we will use the more common term "cupping" here), is a natural wear pattern on motorcycle tires and it will always follow the tread pattern. It is not a sign that you have bad suspension parts. It merely shows that your tire is indeed gripping the road when you make turns (thank you for that Mr. Tire!). This cupping develops within the side wear bands of a leaned motorcycle. The extreme forces that come in to play when the bike is leaned in a turn are what produce the effect and when the wear becomes sufficient, one will experience vibration and noise when one banks into a turn. Upon examination of the pictures at left of our sample rear Avon, our dusted front VTX Dunlop D256, and the picture of our chalked Dunlop D206 one can see how the cupping follows the tread pattern. The leading edge of the tread does not flex much as it grips the road and the rubber is scuffed off the tire in that area causing a depression. As the tire rotates, the pressure moves to the trailing edge of the tread pattern where the tread flexes more causing less scuffing so less material is ground off the tire. The more complex the tread pattern, the more complex the cupping pattern will be. The softer the compound of the tire, the sooner this cupping will develop. Radial tires are more prone to cupping than are bias ply because the compound of radials is softer. As one can see, the simple tread pattern of the Avon pictured produces a simpler scallop pattern while the more complex VTX D256 Dunlop is somewhat involved, though still easily seen in our photo. Cupping on the Valkyrie Dunlop D206 is very hard to photograph because of the complex tread pattern. Low tire pressure will exacerbate this wear pattern and you will lose many serviceable miles by running low. Improper balance has nothing to do with cupping on a motorcycle tire. Improper balance will merely cause your bike to vibrate within certain specific speed ranges.

[SkyDork]

http://www.rattlebars.com/tirewear/index.html

[SkyDork]

Originally Posted by bgmagma10

Thats kinda what I was thinkin too until he said he put a new tire on and its doin the same...

Depending on the tread pattern of the tire and how it's ridden, it could be noticeable within a few hundred miles.

[zx10x2]

Originally Posted by hs1113

Are you sure the triples aren't tweaked or does the frame have any damage? Maybe the axle itself is tweaked or tightened wrong? Just trying to suggest things that could be wrong without really noticing.

Thanks for the reply but I already checked the torque on the axle and had the triples checked.

[JUICEBOX]

This is far out there but have you asked other riders in the area if they are experiencing the same? I only bring this up becuase I used to ride in Birmingham AL and a couple of the roads that we rode all the time wore the front tire almost to an angle on the left side and it was the same for most of the other guys I was riding with. sounds far fetched and may not be related but just throwing it out there.