umm, no... The hole in the center has NOTHING to do with the load. Generally speaking, that isn't even touching the hub in most cases! The hole in the center is not considered a precision machined surface, and is often far from round. Think about it this way, if that was true, and there was even .01mm of difference between the hub and hole, your wheel would be flopping around continously. It would fail fairly quickly.
Lots of vehicles run spacers, including some cars that only see track time. (ie, extreme driving with far more load than a trailer) Shearing the lugs off is actually fairly rare, if the proper spacers are used and everything is tightened down to the proper torque. (you are far more likely to shear lugs from not torquing to spec than using spacers.)
The biggest problem for spacers is that they tend to cause your bearings to wear out faster. The load center is no longer in the actual center of the bearing, so you are riding on an edge all the time.
OP... If you only need a small amount, some spacers like these will work fine.
Keyser Manufacturing Wheel Spacers - SummitRacing.com
