Trailriders Chain Keep I have been building these for over 10 years in my shop. They work really well and are super simple. It pretty much eliminates chain slap and dropped chains. The down side is some noise and a little felt resistance in the drivetrain. Will clutch derailleurs make my guide obsolete? It depends on how much chain retention you want. I just put a SRAM Type 2 rear mech with the clutch on my bike and so far it's really good. I'm still getting some chain slap in fast rough terrain, but no dropped chains so far. I also like the fact that you don't have any resistance added to the drivetrain. For the average XC or Trailrider the new Clutch derailleurs seem to be up to the task of keeping the chain in check. More aggressive riders may want and need more retention. If I was a enduro racer I would run both just to make sure I didn't drop a chain.