Tire has been through four HPDE. The thread depth squares are already gone. I'm concerend about the two tires up front. The other two at the rear seems to wear out just fine. The car is set with -2.5° of camber. Tire is inflated at 36psi (warm). I'm confident the tires are properly inflated as indicated by a tire pyrometer and almost perfect uniform wear through out.

The problem is the outer shoulder of the tire (not sidewall) is wearing out in a ribbed like pattern. It can be seen and felt by hand. The inner patch doesn't show this same pattern. I don't know what to make of it. The undulation is through out the round out of the tire and is perfectly proportioned. I'm guessing it might be the tire construction or soft control arm bushings vibrating causing this problem. My car is fwd. This problem arose after driving at the "streets" of willow-- a very tight course with plenty of 2nd and 3rd gear driving. Lots of throtle manipulation is needed due to limited traction in 2nd gear.

I've taken photo of the tire showing the ribbed round out of the tire.

http://www.we-todd-did-racing.com/we...MxeTU0MQ%3D%3D

Has anyone experienced or can come up with a conclusion why this happened? Thanks.

 

What are your toe and caster angles?

 

caster:
left 2.0°
right 1.8°

toe:
left -.04°
right -.04°

wear is the same on both left and right tire.

 

Pic not working.

 

http://www.we-todd-did-racing.com/we...MxeTU0MQ%3D%3D

Here it is again, hope it works this time. Can anyone else verify the link isn't working?

add. info: the Victos are 205/50/15 on 15X7" wheels w/ 38mm offset. The factory wheel it replaced is 15X6.5" with 39mm offset.

 

it worked for me...

what kind of tire pressures are you running and are you rotating your tires? To be honest i cant really see anything wrong in the picture.

 

I rotate the tires religiously. 36psi is the sweet spot give or take 2psi. I just had them flipped as well.

It's really hard to show the contour of the tire by photo since it is black. Just look at the outline of the tire highligthed by the pavement. You will notice the wavy pattern.. I hope.

 

i sort of see that........ just not sure if there is anything you can do about it - maybe you are overdriving the tires?

 

Might just be normal tire wear with the kumho's. I've seen it on quite a few cars(FWD & RWD) Any chance you could post a pic from above? However i'm not sure a probme is really present, perhaps add some negitive camber.

 

Thanks for the help! The tires may have been over-driven a bit given the condition of the track I drove them on. I will just assume it's a problem associated with that track particular course.

 

fwiw, mine wear the same way. I only autocross them, running pressures of about 39f/45r. Not that it helps you any, but at least you're not alone.

 

I'm not quite sure I'm understanding the wave pattern you're describing, but assuming it's the bumps that show on on the outside shoulders that would sortof make the tire look like a stop-sign with many points when viewed from the side... these evenly spaced bumps, I've seen on practically every Kumho race-compound tire that's been used a bit. Not quite sure why it happens, but it seems to be standard operating procedure.

 

Exactly; these are decendants of R1s, and a lot of them would get that wear pattern.

 

Normal.

The wave corresponds to the original tread blocks. The square corners have worn down to the "sine" curve. All my Kumhos have done that on a completely different car on completely different tracks and conditions. If the V700 was a true slick (no tread), there wouldn't be a wave when worn.

Hope that helps.

 

Were these shaved? I had the same thing happen to my old Victoracers when I tracked at full tread. I think at full tread they just get too hot at the track. Then you get that bumpity-bump around all the corners.

 

Raymund-

It's a problem with the car, just get rid of that POS. Throw another dot 3 crash bot in there and bump it to -3 degrees of camber...

Really though, it's pretty normal, especially when starting at full tread. I would say that it still means you need more negative camber, or the course had tight turn where you were running a little more steering input than you should.

Look at a stock class Camaro sometime. I've seen cord in the middle of those bumbs before, so it can be a problem, but only with really nose heavy cars.

Scott

 

It looks to me that your tires are rolling over and scrubbing the sidewall during cornering. It looks like your picture is of the inside/inboard side of the tire. Is that correct? If so then it might be possible that with your camber settings or tire pressures, you are scrubbing that part of you tire during cornering. For example, when turning right, the inside of your right front tire is rolling over and scrubbing that part of the sidewall. I'm no expert but either adjust your camber settings to put the tire more verticle, or put in some more air pressure to keep the tire from rolling over.

If you want to experiment, put some chalk/white shoe polish/white grease pencil on your tire as an indicator before your next track session. Apply the white stuff starting on the tread and down onto the sidewall to just past where you are seeing the wear pattern. After your session check to see how much, and where, the white indicator has been worn off. This will give you a good idea as to what is happening.

That's my .02. Good luck.

 

Thanks for the help everyone.

Scott, hows your POS holding up? I'm maxed out with dot 3s any chance you know where I can get a hold of some dot 4s-- perhaps a toothpick might work

Pengajim, tire was flipped. The wave pattern used to be on the outside.

Edit:

Jake, they weren't shaved.

If shaven, will the V700 sucumb to the same wear pattern? How much % of tire life will be sacrificed if shaved compared to full thread?


[Modified by Raymund, 9:39 PM 3/7/2003]

 

Then my guess is that you still don't have enough pressure in the tire to keep it from rolling over.