Rear Derailleur Compatibility for Old Bike?
I just bought an old, rusty mountain bike at a garage sale that I want to fix up to take to and from the Metro. It's a Diamondback Sorrento from sometime in the '90's. The bike rides, but the rear gears aren't shifting. The gears are Shimano Acera X. I want to replace the rear derailleur with a low end replacement. What do I need to know about compatibility? Will any Shimano rear derailleur work? Other brands? Thanks in advance.
Insane Bicycle Mechanic
Originally Posted by burck
Any current and 95% of Shimano's older rear derailleurs will work. The exceptions are pre-1985-ish non-index and pre-1997 Dura-Ace derailleurs. You'll have to look very hard to find any of those, so we can round off to 100%.
Also, Taiwan-made Shimano clones (usually Sunrace brand) should work.
Avoid SRAM derailleurs with a number-dot-zero on them (3.0, 7.0, 9.0, etc.). These are not compatible with Shimano indexing.