spacers are not necessarily hard on bearings. it all depends on how far the wheel actually sticks out. the farther it sticks out, the harder it is on bearings. and yes, you will need spacers with 31's on stock wheels. i think i got mine from spidertrax, if i remember correctly. they are 1" spacers. and remember that if you cant find spacers specifically for a trackkick, look for sammy spacers. they are the same bolt pattern.