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Discussion Starter · #1 ·
Hi, I have a 2011 Scott CR1 with 10sp Ultegra groupset.
I want to get a cassette with 36T (34T if I need to) cog so I will need to buy a different RD.

I've read good reviews on the 10 spd Shimano XT RD-M786 SGS Shadow Plus Rear Derailleur working on a road bike--but will this work with my Ultegra STI shifters???
capacity:43T
compatibility:10-Speed Dyna-Sys Shifting Components
max. cog:36T

I've also read that you can NOT mix road bike shifters with MTB derailleurs in recent years.

I want to use either of the following:
SRAM PG-1070 10-speed Cassette 12-36
Shimano Deore XT CS-M771 10-Speed Cassette 11-36

Any opinions or first hand knowledge are appreciated. I'd hate to buy parts and find they don't work, or the Cassette won't fit in my Ultegra wheels.& hubs.
tia, Ron
 

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Up to and including 9 speed they were compatible. I believe Shimano changed the pull ratios at 10sp and 11sp so they will most likely NOT work together
 

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That said, you CAN use a 9sp mtb derailleur with your 10sp road shifters. If cable routing allows, I prefer XT Shadow derailleurs and they will clear a 36t cog. If the cable routing won't work, then a non-shadow version will work but 'may' not clear a 36t. Shadow is RD-M772, non-shadow is RD-M771.
 

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That said, you CAN use a 9sp mtb derailleur with your 10sp road shifters. If cable routing allows, I prefer XT Shadow derailleurs and they will clear a 36t cog. If the cable routing won't work, then a non-shadow version will work but 'may' not clear a 36t. Shadow is RD-M772, non-shadow is RD-M771.
^This^ You can use ANY mtb rear derailleur up to and including 9 speed. Do NOT get a 10 speed derailleur as the cable pull ratio changed. Steer clear of anything that says Dyna-Sys on it, or obviously 11 speed. You can use 7, 8, or 9 speed of any vintage.
 

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Discussion Starter · #5 ·
Thanks guys--I think the Shimano Deore XT RD-M772-SGS Shadow Rear Derailleur will be the one to try first. My concern is if it will work with a 36T.

A reviewer on PB posted:
I use this derailleur along with Shimano XT 11-36T cassette w/my 10 speed Ultegra compact crankset and shifters. Everything works just great

So it's worth a try,
Thanks again and I'll post me results.
 

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According the Shimano's spec sheet, the M772 derailleur is rated only for 34t max rear cog.

The RD M592 SGS is spec'd to 36t max.
 

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According the Shimano's spec sheet, the M772 derailleur is rated only for 34t max rear cog.

The RD M592 SGS is spec'd to 36t max.
That's because those specs were written before Shimano had released ANY cassette going to 36t. Again, the Shadow version (M772) will clear a 36t without any issue. A non-Shadow (M771) will clear most of the time, but not all the time. It depends on the frame and hanger tolerances.

The 592 lists a 36t clearance because it was developed to work the the only 36t 9sp cassette that Shimano made, also a Deore (12-36) that was to be used exclusively on 29" wheels (their words). Remember, the derailleurs we are talking about here are 9sp, full implementation of 36t cassettes didn't happen until 10sp Dynasys.
 

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I just stumbled on the Wolftooth Tanpan, which claims to adapt 11sp (or 10sp) Shimano road shifters to Shimano MTB Rear Derailluers (or possibly SRAM?)

Tanpan ? wolftoothcomponents.com


  • The Tanpan SH10 is compatible with ten-speed Shimano road shifters and optimized for ten-speed Shimano mountain derailleurs.
  • Eleven-speed Shimano mountain derailleurs may be used with only a slight decrease in shifting performance
  • The Tanpan SH11 is compatible with eleven-speed Shimano road shifters and optimized for eleven-speed Shimano mountain derailleurs.
  • Ten-speed Shimano mountain derailleurs may be used with only a slight decrease in shifting performance


  • The Tanpan is designed to mount directly to adjuster-free cable stops on Shimano rear derailleurs.
    • SRAM 1x11 X-Actuation rear derailleurs may be used with a moderate decrease in shifting performance- and the resulting cable routing is not good.
I'm definitely going to try this on my 1x11 Norco Search. I'm currently running Ultegra Shifters and an 11-32 cassette with a wolftooth 42t front chainring.
It's been adequate for 95% of what I ride, but that 5% that needs more gearing... ugh...


 

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I have been eyeing that myself for awhile. Not for the cassette range, rather as a way to put a shadow plus derailleur onto my gravel bike. Let us know how it works out if you pick one up.
 

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M8000 RD, Shimano 11-40 cassette and the Tanpan are due in the next few days. I'll post about it once I've had a chance to play with it.

I hope there is nothing unusual about sizing the chain for this setup.
 

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Discussion Starter · #11 ·
Might need a longer chain. You probably have a spare----but just in case you might need a new one, going from 28 to 40 big cog, and a longer cage i imagine.

And thanks for posting the link. I went an looked over some stuff they have--the RoadLink looks interesting. IF my RD hanger is "standard" I might try that with my current Ultregra GS derailleur before buying an M772 or M592 with a 12-36 PG-1070 or 1050.
 

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^This^ You can use ANY mtb rear derailleur up to and including 9 speed. Do NOT get a 10 speed derailleur as the cable pull ratio changed. Steer clear of anything that says Dyna-Sys on it, or obviously 11 speed. You can use 7, 8, or 9 speed of any vintage.
^That^

And I believe you can't use Shadow either. Am I correct, CX?

Shimano changed the pull ratio of their mountain gearing at 10-speed and their road gearing at 11-speed. So 7-9 speed mountain and 7-10 speed road all have the same pull ratios.
 

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^That^

And I believe you can't use Shadow either. Am I correct, CX?

Shimano changed the pull ratio of their mountain gearing at 10-speed and their road gearing at 11-speed. So 7-9 speed mountain and 7-10 speed road all have the same pull ratios.
The 9 speed shadow derailleurs like the XT M592 SGS would work. The newer shadow plus (clutch) are all Dyna Sys 10 (I think) so they won't work.
 

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The 9 speed shadow derailleurs like the XT M592 SGS would work. The newer shadow plus (clutch) are all Dyna Sys 10 (I think) so they won't work.
Interesting. Thanks!
 

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cx is correct (as usual). I installed a M592 Shadow on my wife's bike several years ago and it has been perfect with her 10-speed Ultegra running gear.

Everything I've read about the 10-speed MTB rear derailleurs is that they are not compatible with the 10-speed road components.
 

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Discussion Starter · #16 ·
I'm the OP, I installed a SRAM 12-36 cassette and a RoadLink ? wolftoothcomponents.com without changing to the M592 Derailleur. Both were simple and they seem to work fine. I don't think I have the Roadlink installed correctly, because the B Screw has no effect. I did not even remove any links from my chain--but once I get home and have a better look at it--I probably will.

I want to thank everyone for their posts--They gave me confidence it would work.
 
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