I recently had both Left side rims snap on my new 500. Both differently to is what was strange. One snapped on the bead lip the other crushed a hole big enough for two fingers to poke trough. What really sucks is it had less than 30 hours on it. After 3 months of debates, polaris said tough luck.

 

What 500 model ATV? Steel or aluminum rims?

 

Aluminum, the same ones as in your icon pic. Got $200 for them on ebay though!

 

I hit a lot of rocks and stumps with mine and haven't had any problems yet. I'll be keeping an eye on them just in case.