ten years of working on cars I can say that you wont wear out a bearing faster with a 1-1.25 maybe even 1.5 spacer. the end result is still bolted to the same location however comma the OVERALL size of a wheel and tire will effect driveline and transmission wear due to the added weight of the rims and tires. Typically bearings are not as effected from spacers or even wheel size. Best example; a shop I worked at had a regular customer come in with trans slipping issues and u-joint problems. his vehicle...a 99 blazer with 24" chrome spoke spinners, each rim and tire weighed as much as one of his standard wheel and tire. the same wear can be expected on with towing as well. good rule of thumb, keep your vehicle maintained and you shouldnt have any problems.