I recently bought an RT-800 with full 7900 kit. I love the bike but I've been having trouble with the RD and right shifter. I've been told by many mechanics that there are known issues with the early 7900 production runs an that later runs have changes that take care of the problems (better RD spring, improved shifter mechanics, etc.). Some mechanics around here in some of the shops will start muttering "F**king Shimano" when you mention 7900 to them .
Specifically, I am having probs with:
I've tried everything I can to address the issues myself (cable upgrades, endless adjusting, calls to Shimano, etc.) I am now in the process of getting warranty replacements for my RD and right shifter from Shimano. This, of course, takes a long time and is going to cost me more money.
Any one else have similar issues? What did you do?
Specifically, I am having probs with:
- The RD shifting up smoothly. The spring does not always pull the chain to the next higher cog smoothly.
- When double-downshifting the ratchet in the shifter does not always engage the second shift [<click><click>), thus the RD will shift down two cogs then slip back one. This often results in the chain riding between two cogs . oh boy. dangerous.
I've tried everything I can to address the issues myself (cable upgrades, endless adjusting, calls to Shimano, etc.) I am now in the process of getting warranty replacements for my RD and right shifter from Shimano. This, of course, takes a long time and is going to cost me more money.
Any one else have similar issues? What did you do?