Get your hands on a new CR-18 rim and compare the thickness to your broken one. That will give you a pretty good idea of how far they can go before failure, though not every rim is going to fail at the same thickness.
The thicker Alex rim should last longer but it's probably heavier too. Your choice. Personally I think 37K out of one rim is pretty good. If your spokes are in good shape I'd just get another CR-18 and swap it over using the method of taping the rims together.
Originally Posted by
rydabent
Here is the biggest reason for disc brakes. They dont wear out expensive rims.
Lol. If rim wear is the "biggest reason" for discs, how many rims did you wear out before you got tired of it and switched to discs?