In the last two season I have put well over 4,000 miles on the Gates C belts on both my Pro's and Axy's. I also run them for performance gain, much less heat fade than OEM. I have noticed they take a set when cold, if you don't warm them up properly I believe you'll have problems. I am a firm believer that those who have problems either have seriously worn motor mounts and or offset/tuning issues. I have never had one grenade so I can't speak for how they supposedly come apart. Great belt for the money and a warranty on top of it.