[Closed] Which rear mech do I need?

also would I need long or short cage?! 😳

I think the 663 is a 2012 model and the other 2 a 2013 models.

Cage length will depend on the cassette & ring size.
Medium is most likely but don't quote me on that. Does the shimano tech info not tell you?

I just put a new XT drivetrain on my fatbike. I used the mid cage(GS) rear derailleur. Chainrings are 24-36 with an 11-36 cassette. Works great!

A long cage rear d is probably needed if you have a wider spacing to your front chainrings that I do.

Needed a new mech after trashing mine in Tenerife. I couldn't get a shadow+ with a mid cage so went with long for same setup as Joe ^^. Still does a fine job on reducing chain slap. CRC have the SLX 10+ for £54

675 is current Shadow+ clutch mech
670 is current non clutch mech
663 is old model non clutch mech