I just smoked another 54t stock spur gear attempting WOT on 4s. I was running on 3 wheel drive because my stock "band-aid" shaft blew in just a few minutes. I'm thinking about the Robinson Gen-3 slipper w/ metal 54t spur. It's only 30 bucks online and I'm in need of a new slipper (and a spur) anyway. So for double the cost maybe I'll save some cash in the long run.