[Nexus313]

Dude - There's alot of stuff on this thread, but here's what I propose. I'm the type of person who cannot live with any vibrations on my car, and have gone through various trial and errors with wheels and tires in the past. Go to a shop that has a road force balancing machine and actually knows what they're doing. Don't go back to the other two shops you went to. Get a third person to check this, and ask them to check EACH wheel. Honestly do some research on google for shops that specialize in road force balance, read the google reviews, give them a call and discuss what I mentioned below before you go to the shop - if they know what you're talking about.. give them a shot, if they have no clue, then you have your answer - KEEP looking for another shop!

1) Put it on the machine and spin it. while it's spinning CLOSELY observing the inner and outer parts of the rim for wobbles. Most of the time, if the wheel is bent, you will see a slight shimmy, if not a a really bad one right off the get go .. that means that particular wheel needs to be repaired or replaced.

2) if the wheel is not bent and spins true, the hunter roadforce machine spits back a number in the bottom left corner, that is called the passenger limit. The roadforce machine measures the roadforce and gives this number back. If this number is greater than 9LB, likely with BMW suspension you will feel it on the highway if you are the type of person to notice vibrations easily. Most people are OK with under 20LB of plimit and don't notice it much. Anything greater than 20LB, you will feel it. This number is comprised of both the road force from the wheel, OR the tire. Usually if the wheel is NOT bent, it is the tire!

3) If the RIM is straight, and the number is greater than 20, I would say, ask the tech to "MATCH MOUNT" the wheel with the tire. This procedure is compromised of unmounting the tire, and matching the tire with the high/low spot of the rim, to reduce the plimit, hence reducing the vibrations.. this is what "road force balancing" is all about. Sometimes when they match mount, this can get the number down or higher, it all depends on many factors such as: the run out of the rim, and the tire roundness. Sometimes depending on the tire brand / quality, you can never get the road force numbers down and need to get a whole new set of tires because the quality is too poor, or bent rims have made the tires develop a weird out of roundness.


Report back to the thread when you have this information from the tire tech & I can help advise on you what you should do to resolve your issue. Without the following information, nothing can really narrow done what the issue with your wheel/tire setup is and why you're having vibrations:

Let us know if:

1) If any of the wheels are ACTUALLY bent. Ask whoever claims the wheel is bent to show you a video of the bent wheel or show you a visual in person. Get some proof rather than some BS "He said/she said" the wheel is bent but the other shop said it's not!
2) What the Plimit on each wheel and tire is.
3) The DOT on the tires and if they have any micro cracking or separation. Sometimes shops have tires sitting around for a long time, in bad storage conditions, and then they sell them to you only for you to be surprised with vibrations on highway speeds.