I've had a balance problem with my Bridgestone Potenza

ReE730s since rotating them. I took tham back to the

dealer who re-balanced and that improved things but I

still had vibrations. I found a local shop that has a

more sophisticated balancing system (a Hunter GSP 9700).

Here is the web site for the equipment used to balance:

http://www.gsp9700.com/

The interesting thing is you can use the site to find

shops that have this eqipment.

The GSP 9700 can place a load on the tire (to simulate

driving conditions) and when they did this they found

my left front tire is pushing pack at a force of 27 lbs

every time it rotates. This probably indicates a variation

in sidewall strength at some point in the tire (very rare

for Bridgestone's to have problems like this the shop

owner noted). He also added that, in general, they

don't want to see more then 6 lbs of force measured.

Also, the tire is balanced when there is no load on the

tire (so the original shop that sold me the tires was

probably balancing them as well as they could using

their equipment).

At this point they recommend I replace the tire or rotate

it to the back and keep it there. The balance is pretty

good now and I only notice the slight problem since I know

to look for it. The other choice is to dismount the tire

and try to position it on the wheel taking into account

the wheel's balance. Apparently you can match up tires

and wheels to reduce vibration this way.

I'll probably replace the tire after I see if the shop where

I purchased it from will replace it (I'm thinking there eyes

are going to glaze over when I tell them my story).

So, if you are having tires mounted you might want to

check the web site listed above and find someone to do it

that has good balancing eqipment.