How do I measure for adapters?

[hardline_42]

I highly suggest going to www.wheeladapter.com and speaking directly with Fred Goeske. He has done all of my wheel adapters and I can't say enough good things about them. To know how thick the adapters need to be, you need to measure the maximum backspacing your suspension will allow you to run. Then, figure out the backspacing of the BMW wheel and subtract one from the other. Make sure you include the thickness of slip-on rotors etc. when you do your calculations. A few things to keep in mind:

1. The adapters need to be HUBCENTRIC to the hub/axle flange and WHEELCENTRIC to the wheel. Any decent adapter manufacturer should know the dimensions for the hub side but you will need to get a measurement of the wheel center for the wheelcentric lip.

2. The BMW pattern is slightly different from the GM 5 on 4.75" pattern. Your wheel adapter manuf. should know this.

3. Upgrade to ARP wheel studs. Even though the design of the adapter effectively makes one solid connection, it's cheap insurance to replace the hub/axle studs with larger, better quality ones. Make sure the adapters come with upgraded studs. Again, it should be included in any quality set of adapters.

4. Expect to pay more for a quality set of adapters. A set of (4) 2.25" adapters w/ everything I mentioned above ran me $375 shipped (only $25 less than the 'vette replicas they were going behind!). Of course, you get what you pay for and wheel adapters is not a place to skimp. Be wary of any eBay or lower priced adapters that are either off-the-shelf items or aren't custom made for your application.