What are the rear derailleur families, offered by Shimano? I need to replace a Shimano Acera derailleur and am trying to decide on a replacement part.
Cross country component
- XTR [M980] (10 speed) – Top of the range for cross-country mountain bikes
- Deore XT [M780] (10 speed)
- SLX [M660] (9 and 10 speed), replaced Deore LX
- Deore [M590] (9 speed) Entry level cross-country mountain bikes
- Non-series (brakeparts, cranks and pedals)
- Deore XT
- Deore LX
- Saint [M820] (10 speed) – Top of the range for downhill and freeride bikes
- Zee [M640] (10 speed)
- Hone [M600] (9 speed) – discontinued in 2008
Recreational mountain bikes component
- Alivio [M410 and M430] (8 and 9 speed)
- Acera [M360] (8 and 9 speed)
- Altus [M310] (8 speed)
- Tourney (6, 7, 8 speed) – Includes several different levels of quality, and can be found on department-store bicycles
The above list was pilfered from Wikipedia.
You're probably best to go with Acera again, to ensure it's compatible. I've had one fitted to my hybrid in the last year, so they're still available.