It really is concerning. I don't know what I will do when I need tires again. One of the Yokohamas is more out of round than the others. The car rides smoothly, but I get a slight shake in the steering wheel since the worst tire is on the front left. As for the Pirellis, two were very good, one was ...

The tire/wheel problems with both my Volvo C30s have finally been resolved! The problems were mostly tire uniformity issues, radial run-out specifically. Discount Tire really went the extra mile to make it right. They upgraded the tires on both cars free of charge and even ordered an additional tire...

The balancer has a big roller that applies force to the tire as it rotates. The number is the variation in force against the roller (I think). It is different from the actual balance. A tire can be balanced, but have a large road force number if it isn't round or straight. Some cars are more sensiti...

Got lucky and found a Volvo Technical Journal on road force balancing. Ref. No. TJ 33867.1.3 Applicable to USA and Canada. It has six pages about what to do when customers complain about vibration at highway speeds. Volvo recommends the Hunter Road Force Elite (same as what Discount Tire has, but pr...

2013 C30: Seems that one of the new wheels has a slight ding in the outer lip - car hasn't even gone over a large bump, so I will probably get that replaced under warranty. I am still considering getting them to replace the Falkens with the Pirelli P7 AS plus 3. The idea is to end up with four tires...

I am considering Pirelli P7 AS plus 3, but I am tempted by the Kumho Ecsta PA51. I have the Kumhos on my corvette and they work well. My biggest concern now is getting a set of tires that are actually round.

Crazy, isn't it? I have 30 days from when I bought the tires to get a different set of tires (just pay the price difference), so I might get a set of Michelin Pilot Sport all seasons 4. The problem with the Falkens is that there is too much radial run-out (if I have my terms correct) on one or two t...

I am still dealing with this problem!! Discount tire checked the balance again and all tires were out of balance. After re-balancing the first tire, I had them take it off the machine and them put it back on. Again, the tire was out of balance. The manager seemed to be the only one who understood th...

Very good question. The hub centric rings are aluminum, I got them off Ebay. They are surprisingly well made. The inner and outer dimensions are correct for the hub/wheel combination. I measured them before installation. The tire store first fitted the wheels with plastic hub centric rings, but I go...

A small update: I had not driven the 2013 C30 after putting the new wheels/tires back on yesterday. When I drove it today, it was a little better - the vibration around 60 mph was less and the vibration at higher speeds was a little better, but it still comes and goes. It feels as though a better ba...