A month or so back I had my Wolverine at the dealer for a few weeks with them trying to find an issue with it shutting off from time to time. (They never fixed the issue) Anyway, while it was there they took my extreme sheave off and took the slug kit out, weights, and spring and put it all back to stock to try that. So I stopped by one day to check out their progress and they had me take it down the road. I immediately could feel the difference and and rolled right back in and told them hell no! Put my shit back on. The slug kit, sheave, weights and spring I got from James truly make night and day difference on the machine. If anybody is on the fence about getting the set-up from James get off and just do it. It's worth every penny.