Just got rims today and there are 2 different sizes of rings. Which are the front and which are the rear?? One set is thicker than the other. Thank you for any info.

 

Rings with larger holes go in the front wheels, smaller holes in the rear. Make sure to check them against the lips on center of the hubs for proper fit!! Very bad news to get them reversed. If the small rings are installed up front they will ride on the centering lips rather than around them; wheel will not flush up against hub, front lugs will loosen, wheel may fall off with much damage, possible death and distruction, etc. Don't ask me how I know...