Backspacing Actual Width vs Stated Width

[Apogee]

Originally Posted by ADiCarlo

...Also whats the maximum recommended spacer to run on the front wheels?

Most people wouldn't recommend running a spacer, however considering that a slip on rotor is generall 1/4" to 3/8" through the hat, it would stand to reason that anything 1/2" or less properly designed and installed shouldn't create any problems. Avoid the cheap die-cast aluminum spacers as they're prone to failing, usually when you really can't afford for them to fail. Stick with quality 6061 or 7075 spacers and all should be well.

FWIW, I have a friend who runs 1.4" loose spacers on a 4200# car with no issues for several years and many 10's of thousands of miles, however they're hub-centric with ~.002" slip fit and he runs M14 wheel studs torqued to 135 ft-lb. The spacers themselves also have reliefs around the wheel studs holes to maintain as even a stress concentration between the spacer and hub/rotor as possible, minimizing the chance to lose lug nut preload/torque due to localized material failure around the stud, something relatively common with inexpensive bolt-on type wheel adapters.

In general, for any spacer at or over 1" thick, 7/8" if you can fit the lug nuts on the inner pattern, I would be looking at a bolt-on type adapter/spacer.

Tobin
KORE3