A note for those changing you're own tires

[camone]

Most of you are probably smarter then this,so I write this for anyone as dumb as me. Having the 21" P-zeros I decided to call The Tire Rack for new rims and tires to use for winter. When the tires arrived mounted,balanced and ready to go I changed them over myself.All was well. The Pirelli Sporpion Ice and Snow tires worked great. Two weeks ago I changed back over to the P-zeroes. Several days later I had to take a several hundred mile trip. I noticed a slight vibration.Yesterday I took it in for an oil change and had them check my tires out. When I changed back to the P-zeroes,a spacer on the right rear had stayed stuck on the car.I didn't even know that it had a spacer.It took the tech.about 15 min. to pry the spacer off the car. Had I gone much further it could've caused damage to my stock rim.Lesson learned!!!!

[SSMickey]

Those spacers are called hub-centric rings. I'd bet that over half of vibration problems with aftermarket wheels can be traced to these things. Or lack of most of the time.