Shimano XT rear derailleur changes

[KevinGT]

Can someone explain what changed in the Shimano XT rear derailleurs in the last two years? From what I can tell, the progression went:

780
781
786

I don't see that there was ever a 785 version even though most of the rest of the drivetrain came in a 785 at one time.

I can see from some pictures that the "stabilizer switch" was added for the 786. Other than that, I can't find the difference.

[RSabarese]

From what I know, M780 and M781 are very close, but M781 supports the new direct mount derailleur hanger by removing B-Pivot. M786 is the clutch based shadow plus version of the M781 with support for the DM derailleur hanger as well.

[KevinGT]

From what I know, M780 and M781 are very close, but M781 supports the new direct mount derailleur hanger by removing B-Pivot. M786 is the clutch based shadow plus version of the M781 with support for the DM derailleur hanger as well.

What's a "clutch based shadow plus" version? Is that the switch to tighten the spring tension?

[ridefast84]

with the clutch based version the derailleur locks out and eliminates chain slap.

[KevinGT]

Thanks!

[ridefast84]

Just spend the extra for the clutch, its the hot setup.

[customfab]

The 780 and 785 were the non direct mount compatible versions. 781 and 786 are the normal and shadow plus versions that are direct mount compatible. They did this as a running change.

[KevinGT]

So let me make sure I've got this straight:

780: normal mount, no clutch
781: direct mount, no clutch
785: normal mount, clutch
786: direct mount, clutch

That it? Since I have a normal hanger and mainly ride trail/XC, seems the 780 is the right choice. But with the prices so close, I might as well grab a 786.

[ridefast84]

The 786 is the hot set up!!! I might upgrade as well.

[KevinGT]

Tell me more about this hot setup! Is it simply a lever that increases the spring tension to reduce chain slap?

If that's what it is, why not just permanently increase the chain tension and remove the lever? Surely there's more to it than that.

[RSabarese]

It's actually a friction clutch, not just increased tension and has adjustability with a small internal screw as the clutch wears. Also, leaving it on all the time would make removing the rear wheel much more difficult.

[ridefast84]

this is the xtr version
2012 Shimano XTR Shadow Plus - YouTube

[KevinGT]

Freakin' cool technology.

Sold! Thanks.