Truing tires from radial runout

[rubberchicken]

Originally Posted by JohnnyJohnson
Originally Posted by Snagglefoot
I've seen references to companies that can shave a tire that's been flat spotted due to a skid stop, but I've never actually found one up here that does it.


Its called sipping used to be offered a few years ago. Its been year now since someone asked me if I wanted to have them sip my tires. Oh thing I can think of it was used to allow manufacturers to make below spec tires.

https://www.youtube.com/watch?v=Jtk4ijS4gOo



I think what he was looking for is "tire shaving", as opposed to tire siping.

 

[sasilverbullet]

Originally Posted by CapriRacer
First, find someone with a Hunter GSP9700. GSP9700 Locator Have them perform a match mount. While you mentioned they reindexed the tire on the wheel, maybe they just reindexed without knowing what the values were, where the peaks were, and whether that was going to fix the problem.

Second, truing a tire may not fix your problem - which is why the procedure kind of died out. Ya' see, only about 60% of a tire's uniformity is tied to runout. The rest is tied to stiffness, which you can't fix.

Third, it might be that the wheel isn't center pikloted - meaning, the wheel isn't being centered on the hub. Are these after market wheels? If so, then you might need a hub ring to get them centered.

And lastly, just because you can't see wobble in the wheel doesn't mean it isn't there. a small amount of wobble at the wheel is amplified at the tire. That's where the Hunter GSP9700 comes in. It also measured the wheel. The key to all this is the operator.

So if you find a GSP9700, have the operator make a note of the before assembly values, the before values of the tire and wheel (2 separate numbers), what the predicted matched value is going to be, and what the final value was. Just be aware that a tire can flatspotted so much that the flatspot is permanent, and can't be corrected by matching the high spot of the tire to the low spot of the wheel.


I wish you were the tire tech at my local Discount Tire! The local Porsche dealer is very knowledgeable also, but it's a month wait to get anything done!