XT di2 rear derailleur Cassette Options

Especially for light weight issues concerning cyclocross / touring bikes & parts.

Moderator: Moderator Team

Post Reply
velobob
Posts: 25
Joined: Sun Mar 27, 2005 4:50 pm

by velobob

I am thinking of replacing an Ultegra Di2 short cage rear der with an XT Di2 medium cage on my giant tcx advanced 1 cross bike. I have RS785 hydraulic shifters. The goal is twofold - first to increase the size of the cassette to 11-32 (the max I can run now is 11-28) and second to get the clutch system.

I believe the shifters are compatible but the question I have is - can I run 11-32 road cassettes or would I have to run 11-40 or 11-42 mtn bike cassettes? I've read conflicting things on this. I have noticed however that the new Cannondale SuperX top model is spec'd with the XT Di2 rear derailleur and an 11-32 105 cassette so I think I should be fine.

Any insights much appreciated!

boots2000
Posts: 1409
Joined: Mon Oct 15, 2007 9:28 pm

by boots2000

Shifters are compatible, but in my experience the mtb derailleur plays better with the 11-40 or 11-42.

by Weenie


ooo
Posts: 446
Joined: Sat May 21, 2016 12:59 pm

by ooo

xt di2 can do 11-28
ultegra ss can do 11-32
for 1x ... clutch is 2 step forward, but longer cage (gs vs ss) is one step back
'

velobob
Posts: 25
Joined: Sun Mar 27, 2005 4:50 pm

by velobob

ooo wrote:xt di2 can do 11-28
ultegra ss can do 11-32
for 1x ... clutch is 2 step forward, but longer cage (gs vs ss) is one step back


why is longer cage one step back?

Bhaalgorn
Posts: 20
Joined: Mon Jun 05, 2017 2:10 pm

by Bhaalgorn

I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.

velobob
Posts: 25
Joined: Sun Mar 27, 2005 4:50 pm

by velobob

Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


this is good to know - thx!

hurricanejosh
Posts: 20
Joined: Wed Nov 13, 2013 7:20 pm
Location: Edmonton, AB

by hurricanejosh

the shimano 11 speed road & MTB chains and cassettes use the same spacing. the difference is how it sits on the freehub body. XT and XTR cassettes will fit on 10 speed road wheels, where 11 speed 105/ultegra/duraace cassettes require a wider 11 speed freehub body.

velobob
Posts: 25
Joined: Sun Mar 27, 2005 4:50 pm

by velobob

Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


what kind of cassette is the 11-36?

User avatar
wheelsONfire
Posts: 1757
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

velobob wrote:
Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


what kind of cassette is the 11-36?


You can use Sram PG-1170, 11-36.
I do with 6870, 6870 RD medium cage + Wolf tooth Roadlink.
But i run 2*11 if it matters.
Bikes:

Ax Lightness Vial EVO D
Paduano Racing Fidia
Open *UP*
https://opencycle.com/showcase/the-xplo ... eelsonfire

Bhaalgorn
Posts: 20
Joined: Mon Jun 05, 2017 2:10 pm

by Bhaalgorn

velobob wrote:
Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


what kind of cassette is the 11-36?


I don't think it matters.

11-28 is an Ultegra. 11-32 is a PG1170. 11-36 is PG1140. All with SRAM PG1170 and KMC X11SL chains.

DutchMountains
Posts: 87
Joined: Sat Aug 20, 2016 9:16 pm

by DutchMountains

I'm using 14-32 (combination of Ultegra 14-28 junior cassette and 11-31) with XT Di2 and RS785 shifters. Works fine. Front rings are 34/42.

The only thing is that syncro shift doesn't work with the XT Di2 when you have the regular road junction, you MUST have the SC-MT800 :(

User avatar
ultimobici
in the industry
Posts: 2984
Joined: Sun Nov 21, 2004 2:45 pm
Location: London, UK
Contact:

by ultimobici

Are you planning on ditching the front mech? If so it is compatible. If not it will not work as the system can only function with both mechs being MTB or both being Road. If you want to use an 11-32, why not just swap out the mech for a 6870GS mech?

User avatar
wheelsONfire
Posts: 1757
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

Bhaalgorn wrote:
velobob wrote:
Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


what kind of cassette is the 11-36?


I don't think it matters.

11-28 is an Ultegra. 11-32 is a PG1170. 11-36 is PG1140. All with SRAM PG1170 and KMC X11SL chains.


That is not correct.

I have two PG-1170, 11-36.
https://www.sram.com/sram/road/products ... 13fys5wzrw

As mentioned, you easily use these with 6870 GS (medium cage) + Wolf tooth Roadlink.
https://www.wolftoothcomponents.com/products/roadlink

On top of that, you can run TA Specialities 44T or even 42T large chainring and 33T small chainring.

I run Shimano CN-HG901 chain.
Bikes:

Ax Lightness Vial EVO D
Paduano Racing Fidia
Open *UP*
https://opencycle.com/showcase/the-xplo ... eelsonfire

Bhaalgorn
Posts: 20
Joined: Mon Jun 05, 2017 2:10 pm

by Bhaalgorn

wheelsONfire wrote:
Bhaalgorn wrote:
velobob wrote:
Bhaalgorn wrote:I'm running RS785 brifters + 11-28 cassette + long-cage XTR Di2 derailleur in 1x right now with no problems. I also run with 11-32 and 11-36.


what kind of cassette is the 11-36?


I don't think it matters.

11-28 is an Ultegra. 11-32 is a PG1170. 11-36 is PG1140. All with SRAM PG1170 and KMC X11SL chains.


That is not correct.


What isn't correct? The brand of the cassette doesn't matter.

User avatar
wheelsONfire
Posts: 1757
Joined: Mon Jul 07, 2014 8:15 am
Location: NorthEU

by wheelsONfire

PG-1170 is for sure 11-36 as proven by the link.
Or did you mean what you yourself use?
If so, my mistake. I thought you ment PG-1170 is not available as 11-36, only PG-1140,
Bikes:

Ax Lightness Vial EVO D
Paduano Racing Fidia
Open *UP*
https://opencycle.com/showcase/the-xplo ... eelsonfire

by Weenie


Post Reply
  • Similar Topics
    Replies
    Views
    Last post