I personally haven't had any issues with proper break in and 300 miles, but a couple of my riding partners have. Enough so we carry an extra belt and the Polaris tools to change it. My question is.... Why couldn't someone make the top pulley bigger and the bottom pulley a little smaller giving the sled the same gear ratio, but allowing more surface area on the upper pulley??? Wish I had the ability to make a set up like this and try it out. Any thoughts???