Tires: out of round tires, hunter gsp9700, lateral run

Question
how much does a tire have to be to create a problem balancing it. i have 195 60 x 15 out by .070 " what is acceptable? in the industry

Answer
Woody,


Out of round doesn't correlate well to vibration problems.  BTW, I am assuming we are discussing radial run out.  Hardly ever is lateral run out (side to side) an issue.

It has been decades since the adoption of TUG (Tire Uniformity Graders) by tire manufacturers and the industry has moved away from using run out as a criteria and uses Force Variation instead - and that prompted the development of the Hunter GSP9700 - a more affordable version of a TUG.  Something a good tire shop should have to diagnose vibration problems.

In the days before the Hunter GSP9700, run out was the only tool we had, so we used it.  One of the problems was that individual tread elements would make measuring the run out "cagy" at best.  

But now that this tool is available, it would be foolish to use some less reliable method.  Besides the Hunter GSP9700 has the capability of measuring the rim and factoring it out so that you have the effect of the tire by itself.

0.070" is a fairly large number as run outs go.  The problem is that you have to factor out the effect of the rim - which can be difficult.

BTW, you should be aware that it is easily possible to wear run out (and force variation) into a tire - which is why tire manufacturer do not warrant vibration tires that show signs of wear.