I have been on the phone with Mark @ AKA. They have a stonger rim coming out (something to do with the plastic they are made with). I cracked 4 rims and he sent me new rims and tires (siince there were cityblocks). I had to send the cracked rims/tires back to them. No questions asked for the new set. The new rims are in and should be shipping. I will have to pull up my email telling you how to tell the differance between the old and new. If you have a set of the old rims, boil them for 3 minutes before you mount them and you should be fine.