# Mountain bike rear derailleur with Ultegra shifter



## robwh9 (Sep 2, 2004)

I want to lower the gearing of my road bike by using a mountain bike cassette and a compatable mountain bike rear derailleur (longer chain too). Will this work with an Ultegra (road) shifter? I mean, does an Ultegra shifter pull as much cable as an mtb shifter?


----------



## cxwrench (Nov 9, 2004)

holy crap this has been covered numerous times this year and last. if you have shimano 10 speed road shifters, you need a shimano 9 speed mtb derailleur, and a 10 speed mtb cassette. a shimano 10 speed dyna-sys derailleur will NOT work. i'd recommend going w/ an 'older' style derailleur vs a 'shadow' type, that way you can switch back and forth and use the same cable/housing if you want to.


----------



## tednugent (Apr 26, 2010)

for new (not used).... Shimano has gone shadow for XTR, Saint (DH), XT, and SLX ....

Left with a Deore M591 or Alivio M430....

imo,...
XTR = Dura Ace
XT = Ultegra
SLX = 105

Deore = Tiagra
Alivio = Sora/2300


----------



## Ventruck (Mar 9, 2009)

cxwrench said:


> holy crap this has been covered numerous times this year and last. if you have shimano 10 speed road shifters, you need a shimano 9 speed mtb derailleur, and a 10 speed mtb cassette. a shimano 10 speed dyna-sys derailleur will NOT work. i'd recommend going w/ an 'older' style derailleur vs a 'shadow' type, that way you can switch back and forth and use the same cable/housing if you want to.


Indeed a tired out topic. Been discussed at numerous boards at this point.

but yeah to add to the testimonies OP: I had 6600 Ultegra shifters going to a M581 LX long cage derailleur. Mainly did it because my 105 RD had a stiff pivot. Never bothered changing back when I fixed that.

Really don't get the point of ted mentioning that hierarchy ladder.


----------



## tednugent (Apr 26, 2010)

someone is bound to ask about the hierarchy of the MTB groups.

If someone spent money to buy an Ultegra... I think someone would like a MTB equivalent of the Ultegra for the Shimano quasi-WiFLi setup


----------



## MMinSC (Nov 19, 2011)

Hate to say it, but folks were running MTB r/d with STI setups before SRAM ever though of "WiFli". I've run both...
Force with X9 R/D and Shimano STI (Ultegra and D/A) with XT and XTR R/Ds. The Shimano works better. Currently running D/A 7800 with XTR mid cage on my CX bike. Works perfectly. Can't tell a difference between XTR and D/A.


----------



## tednugent (Apr 26, 2010)

MMinSC said:


> Hate to say it, but folks were running MTB r/d with STI setups before SRAM ever though of "WiFli". I've run both...
> Force with X9 R/D and Shimano STI (Ultegra and D/A) with XT and XTR R/Ds. The Shimano works better. Currently running D/A 7800 with XTR mid cage on my CX bike. Works perfectly. Can't tell a difference between XTR and D/A.


"Kansas" Bob Sutton has been a huge proponent of the MTB gearing for quite some time, well before SRAM introduced WiFLi in the Apex, while people have been berating him for using MTB cassettes/RD's.


----------



## MMinSC (Nov 19, 2011)

tednugent said:


> "Kansas" Bob Sutton has been a huge proponent of the MTB gearing for quite some time, well before SRAM introduced WiFLi in the Apex, while people have been berating him for using MTB cassettes/RD's.


Never used anything bigger than a 38/28, but it's nice knowing the options are there. I run MTB R/Ds on the CX bikes b/c they have proven to be a bit tougher. (knocks on wood)


----------



## Bostic (Nov 17, 2008)

I reversed the B screw on a 6703 mid cage Ultegra rear dérailleur to get clearance for a 10 speed XT 11-32 cassette on our Cannondale road tandem. It came with an IRC11-32 cassette that shifted terrible. For whatever reason the 32 cog on the IRC cleared the pulley but the Shimano would not until I did the reversal.


----------



## robwh9 (Sep 2, 2004)

MMinSC said:


> Hate to say it, but folks were running MTB r/d with STI setups before SRAM ever though of "WiFli". I've run both...
> Force with X9 R/D and Shimano STI (Ultegra and D/A) with XT and XTR R/Ds. The Shimano works better. Currently running D/A 7800 with XTR mid cage on my CX bike. Works perfectly. Can't tell a difference between XTR and D/A.


The thing is, I bought an XT rear derailleur and it doesn't work with the Ultegra shifter. The guy at Performance said it would. It can't shift to the 2 largest cogs. I've tried backing off the limit screw completely, adjusted the B screw, and increased the cable tension so much that it can't even shift to the smallest cog, and still no good. The XT derailleur is compatable with the 36-tooth cassette. I guess I have to find an older style derailleur that will work with a 36-tooth cassette.

I do weekend touring with a seatpost rack and about 15 pounds of gear. I need the low gearing to get over the Santa Cruz mountains.

Thanks for your advise and sorry about not Googling the topic first.


----------



## redlude97 (Jun 29, 2010)

robwh9 said:


> The thing is, I bought an XT rear derailleur and it doesn't work with the Ultegra shifter. The guy at Performance said it would. It can't shift to the 2 largest cogs. I've tried backing off the limit screw completely, adjusted the B screw, and increased the cable tension so much that it can't even shift to the smallest cog, and still no good. The XT derailleur is compatable with the 36-tooth cassette. I guess I have to find an older style derailleur that will work with a 36-tooth cassette.
> 
> I do weekend touring with a seatpost rack and about 15 pounds of gear. I need the low gearing to get over the Santa Cruz mountains.
> 
> Thanks for your advise and sorry about not Googling the topic first.


Is it a 10-speed XT RD?


----------



## ziscwg (Apr 19, 2010)

redlude97 said:


> Is it a 10-speed XT RD?


This is what I'm thinking. He got a 10 spd when he needed 9 spd. 

Too bad as the XT series is the work horse of the shimano mtb group. Works, reasonably lite and a decent price.


----------



## Kontact (Apr 1, 2011)

MMinSC said:


> Hate to say it, but folks were running MTB r/d with STI setups before SRAM ever though of "WiFli". I've run both...
> Force with X9 R/D and Shimano STI (Ultegra and D/A) with XT and XTR R/Ds. The Shimano works better. Currently running D/A 7800 with XTR mid cage on my CX bike. Works perfectly. Can't tell a difference between XTR and D/A.


This isn't news. "Deore" was a touring rear derailleur before anyone ever invented the MTB and hung one on it. Trek was putting Deore derailleurs on touring road bike with indexed road derailleurs 25 years ago.

I doubt this would even be a question if it hadn't been for both SRAM and Shimano making some of the their road/mtb parts incompatible, and so many folks (including the guy at Performance that should have known better) didn't keep up with the changes.


----------



## robwh9 (Sep 2, 2004)

ziscwg said:


> This is what I'm thinking. He got a 10 spd when he needed 9 spd.


Yeah, I noticed that parts of the derailleur move differently when you shift. I guess that's the dyna system, which won't work apparently with an Ultegra shifter. 

So all 9 speed are pre-dyno, so they'll work?


----------



## Bostic (Nov 17, 2008)

robwh9 said:


> I do weekend touring with a seatpost rack and about 15 pounds of gear. I need the low gearing to get over the Santa Cruz mountains


Alba and Jamison Creek are very tough climbs. Are they part of your route?


----------



## tednugent (Apr 26, 2010)

robwh9 said:


> Yeah, I noticed that parts of the derailleur move differently when you shift. I guess that's the dyna system, which won't work apparently with an Ultegra shifter.
> 
> So all 9 speed are pre-dyno, so they'll work?


Yes. 9-speeds and below are not Dyna-Sys


----------



## robwh9 (Sep 2, 2004)

Bostic said:


> Alba and Jamison Creek are very tough climbs. Are they part of your route?


From Sunnyvale, I'll load my lightweight camping gear and a change of clothing on my bike and ride out to Half Moon Bay State Beach (via Old la Honda or Kings Mountain Rd), New Brighton State Beach (via Old Santa Cruz Rd), or Veterans Memorial Park in Monterey (via Old Santa Cruz Rd). Sometimes I'll start in Monterey and ride down to Pfeiffer Big Sur State Park. Each has a large site set aside for bicycle tourists for $5 a night. Camp there and ride back the next day. It's a great escape from city life.

Alba and Jamison Creek are STEEP. When I rode up Jamison Creek I could smell the brakes of a car coming down.

I sometimes ride out to Half Moon Bay for the Pumpkin Festival.


----------



## cxwrench (Nov 9, 2004)

i live way too close to have never ridden that stuff...one of these days i swear i'll do some riding around the santa cruz area. i'm only 1.5hrs away and do cx races down there every now and then. 

make sure you didn't get the 10speed dyna sys derailleur as others have said and you should be fine.


----------



## Ventura Roubaix (Oct 10, 2009)

I run 10 spd 5600 105 shifters with a 9 spd Deore XT 771 RD on a Sram 11-32 cassette, shifts good, no problems after I got my RD hanger straighten.


----------



## cxwrench (Nov 9, 2004)

Bostic said:


> I reversed the B screw on a 6703 mid cage Ultegra rear dérailleur to get clearance for a 10 speed XT 11-32 cassette on our Cannondale road tandem. It came with an IRC11-32 cassette that shifted terrible. For whatever reason the 32 cog on the IRC cleared the pulley but the Shimano would not until I did the reversal.


not a great idea, especially on a tandem. when you bury the b screw you're reducing the number of teeth the chain wraps. a mtb derailleur would allow you to keep the chain in contact w/ more teeth on the big cogs and reduce the chance of a slightly worn chain from skipping. 
and your cassette is IRD, not IRC.


----------



## ogre (Dec 16, 2005)

Ok, a bit of thread dredge, but most talk is around the rear. I want to make sure about the front, as I'm looking at a cross frame I want to put Ultegra 6700 on. The frame has top tube cable routing, so I need a top pull front derailleur. Will an XT or XTR (M780/M980) work? I found one thread saying no way, and one guy saying he's doing it.


----------

