Quote Originally Posted by Jake View Post
but thick spacers make me a bit nervous without another set of bolts.
hub-cebtric spacer and wheel keeps misalignment down to near zero. using nuts to secure the spacer to the hub on elongated studs adds a small margin of safety and can be accomodated on thick spacers. doubling the number of bolts doubles the number of failure points for all failure modes associated with the studs, as well as noting that the wheel studs are pressed into aluminum and that a small misalignment of the wheel means a greater angular deformation of the "second" stud than the same misalignment and long studs (because of the spacer). that greater angle is supported in the steel into aluminum press fit which is much weaker than the steel-steel press fit at the hub.

generally this all works out to be plenty safe and strong enough, but why add the weight and complexity when, if done right, long studs through the spacer are the better solution in all respects except maybe cost, which isn't at all prohibitive?