Whats the difference m770vs m771 vs m772 GS SGS?

im looking to upgrade my drive train. im not sure what makes the biggest difference in smoother better shifting. Currently i have and SLX rear Derail on a xt cassette and deore shifters. I would like to upgrade one of these components for now, what would be my best option rear derail or the shifters? and is the xtr worth it over xt parts? and i have no idea what to get with all the different models. Some help would be aprreciated thanks!

 

770 is normal, 771 is reverse, and 772 is low-profile i am 90% sure. Your drivetrain components look good though. I don't know if I'd spend the money on upgrading them if they aren't broken. GS is medium cage I think and SGS is long.

If I had to change one of the components I'd probably go after your shifters, but I'd do a little research on whether the ones you want still have the same internals as the ones you have.

 

Hello upgrade the shifters to XT, along with a M770 XT Rear deraillur standard cage. Thanks and have fun.

 

Bad advice.

The M770 is the retard rise (low normal at rest). It's also the "old style" cage This will not work with conventional XT shifters. He'd have to get the Dual Control shifter/brake levers.
The M771 is the normal shifting (top normal at rest). It's also the "old style" cage.
The M772 is the Shadow type derailleur, just arguably slightly better than his SLX derailleur (the SLX is the Shadow type).

These can be compared here: http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/mountain/deore_xt.html

GS > medium cage (generally used for dual front chainrings)
SGS > long cage (generally used for triple front chainrings)

This doesn't sound like a good upgrade plan. The SLX derailleur and the Deore shifters are good components. All in all, I'd bet that the bike would better benefit from other upgrades that would be noticeable.

 

+1 on those components being more than adequate; you could spend a lot and lose a little (weight).

 

Not sure why people/documentation say that the rapid rise m770 must be used with the dual control levers. It's the same spacing/actuation ratio. I use m770 rapid rise rear der with XTR M970 shifters. Works beautifully. I like the RR so I can quickly shift to granny on those sudden climbs. Releasing has always been easier for me.

Also, I disagree with the shifter comment. I've used both deore, lx, and xtr shifters (not XT). I like the adjustable bracket on the XT/XTR. Without the optical display, you can run the shifters both inside or outside the brake levers. For most people, the standard setup should be okay. For me with weirdly wide hands and an ergon grip/barend, the adjustment is important. Also, the deore/LX shifters feel like I'm going to snap the levers when I tighten. I love the brushed aluminum thumbie on the XTR shifter.