SHIMANO Ultegra RD RX800 Rear Derailleur Review

Effectively eliminates chain noise. Helped solve my problem with the chain falling off the chain. It should also be noted that it works with a 10 speed Tiagra 4700. However, it will not work with other Shimano 10 speed groupsets. The Tiagra 4700 has the same gear ratio as the Shimano 11-speed group.

Works great. The clutch effectively prevents the chain from slipping. Even on a Kona Rove with Propeller b, this derailleur can shift almost completely through the entire range of the 11-42t SLX MTB cassette and it doesn't skip gears or skip shifts. I am sure that with the recommended maximum range it will shift smoother and faster. But it works. 11-46 will most likely hit the pulley.

I got the new one with a new bike and in the first 500 miles the derailleur broke in half. Luckily it was still under warranty and I got a new one. My other bike also had an R8000 RD (short cage) and the inner part that houses the spring broke. This was out of warranty but hardly used. I know nothing lasts forever, but my old Ultegra 6800 RD has about 15,000 miles on it and is still running after a couple of crashes. My 2 new Ultegra rear derailleurs never broke and didn't last long with a lot…