Tires: tires have dents on sidewalls, stregth, klms
QuestionHi
I purchased a set of tires from cosco BF Goodich 215 170 R14 in dec.2004. I've put 13000 klms on them since . In jan. I noticed vibrations on the highway but thought its probley due to snow&ice buildup in the rims.Two weeks later after taking my car to the carwash I noticed each tire has indents on the side walls,as many as 1 to 3 . Now I,ve brought my car back to cosco, they say its normal.vibrations caused by ice snow on rims,so they balance all 4 tires.Apon driving home the vibration is still there.
My Question is why do my tires have dips on the sidewalls I don't think this is normal because I,ve looked at other cars in the parking lot at cosco and have yet to find any tires with this problem! Mazda 2300 pickup 1997
AnswerHello, Dave
The indents in the sidewall of most tires is normal. The sidewall has poly cords and they are put together by sandwiching the cords between 2 layers of rubber. The indends you speek of are where they join them. They overlap the cord by 4 or 5 and thats what causes the indents. It is really stronger than the rest of the sidwall. If you see bulges thats when you have a problem because they are weak spots. Most tires will only have one poly joint in the sidewall. Looks like you may have got tires that had several pieces put in. That could cause vibration in the tires depending how they are spaced. Think of it like this, if you had a bunch of springs attached to the wheel and the outside diameter of the tire. The springs should all be the same stregth. but if several are stiffer and they are not evenly spaced you will get vibration has the tire rolls. Has you speed up this vibration gets worse. It has nothing to do with balance. balance is a heavy spot on the outside of the tire and will cause a bump. Vibration is caused by stiff spots in the sidewall. Mostly due to product start points being stacked together or the poly cords being differant lenths. I would take them back and ask for replacements.
Hope this helps
Jack
