# Shimano 10 speed Dyna-Sys cassettes compatible with 10 speed road cassettes?



## aclinjury (Sep 12, 2011)

Can a shimano mtb XTR M980 11-34t cassette be used in a 10 speed Ultegra 6700 system? I believe the pitch spacing of the 10speed DynaSys cassette is the same as the pitch spacing of a 10speed road cassette right? If they are they same, then they are compatible, right?

For the rear derailleur, a Shimano RD5701-GS is used, and its max cog is listed at 32t when used with a double crank. So I think an 11-34t cassette will also fit in there.

Another question, will an 11-36t cassette fit with the RD5701-GS?? Derailleur hanger is long for a road frame, so I think it may work. Besides, there have been many success stories of shimano rear derailleur spec'd for a 28t max cassette but folks have fit 32t cassette in there ok. So I'm thinking the RD5701-GS spec for 32t max might be able to take a 36t provided the derailleur hanger is long enough? (I've also read some tricks such as to use a smaller 10t upper pulley, and a longer b-tension screw, to make the fitting a tad better)

I just need to be sure that 10spd DynaSys cassettes have the same pitch spacing as those of 10spd road cassettes.


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## cxwrench (Nov 9, 2004)

Do it all the time. Dyna-Sys works w/ road. Well, Dyna-Sys cog spacing is the same. The 36 might work, the only way to know is to try, but if the hanger is long...it just might work.


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## aclinjury (Sep 12, 2011)

thanks for the reply, just what I wanted to hear about the cog spacing.

now if the RD5701-GS can't take a 36t, then i'm thinking of getting either of these 4 shimano 9spd mtb derailleurs: 

XT M771
XT M772

XTR M971
XTR M972

All these are high normal, so they should jive well with the Ultegra 6700 brifters, oops shifters. The M771 and M971 are non-shadow. The M772 and its equivalent M972 are shadow. Now, based on my googling, shadow derailleurs are narrower in profile and have a direct connect to the shift cable. Narrow profile is good for mtb because it can better avoid being banged up by rocks, and direct connection of the shifter cable allows better shifting due to less cable friction. So, I guess my question is, is this true? and should I go for the M772/M972 shadow types for the better shifting action? (since this is for a gravel bike, narrower derailleur profile is not as important than for an mtb bike, but hey, I think narrower makes the bike look cleaner right?)

I found this youtube video that mates an M772 to an Ultegra 6700 shifter:
https://www.youtube.com/watch?v=N3Xgh5C-hH8

your thoughts?


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## cxwrench (Nov 9, 2004)

aclinjury said:


> thanks for the reply, just what I wanted to hear about the cog spacing.
> 
> now if the RD5701-GS can't take a 36t, then i'm thinking of getting either of these 4 shimano 9spd mtb derailleurs:
> 
> ...


I'd go w/ the non-Shadow models because they have the rear facing cable entry. IME the Shadow derailleurs usually result in a very short piece of housing that actually increases friction over a nice big loop, at least on most road bikes. I (and every other pro mechanic I know) am a big fan of big loops back there. Friction is a non issue if you replace the cables/housing once a year or so. The big loop makes for smooth shifting. You can even insert a barrel adjuster into the derailleur housing if you run a big loop, unless the frame has external adjusters then it's not needed. 
Here's an example of how long I cut the rear piece of housing.


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## aclinjury (Sep 12, 2011)

ah thanks for the pic. You've answered a lot of what's on my mind.

next time when I'm changing housing, looks like i'll need to make all my rear deraileur cable loops big like yours!


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## robt57 (Jul 23, 2011)

I am also a proponent of a long rear loop. Also prefer using a metal cable end at the DR with chain stay cable route with non dyna DR over the plastic when using Shimano housings.

I will add this pic for seat stay cable route relevancy on my recent Strong custom. I did full cable runs by design and this shifts crisp and perfect with 10 speed bar cons.

I think now that this worked so well I will stick dyna with seat stay cable route. And never a loop snag, although even with 13-14" loops on non dyna setup I only get snags piling bikes in the garage [leaning/piling].


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## cxwrench (Nov 9, 2004)

robt57 said:


> I am also a proponent of a long rear loop. Also prefer using a metal cable end at the DR with chain stay cable route with non dyna DR over the plastic when using Shimano housings.
> 
> I will add this pic for seat stay cable route relevancy on my recent Strong custom. I did full cable runs by design and this shifts crisp and perfect with 10 speed bar cons.
> 
> I think now that this worked so well I will stick dyna with seat stay cable route. And never a loop snag, although even with 13-14" loops on non dyna setup I only get snags piling bikes in the garage [leaning/piling].


Good point on the metal ferrule where the housing goes into the derailleur. Shimano does this on their high end cable/housing sets. Your Strong has the perfect placement of the housing guide to use the Shadow derailleur.


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## Lelandjt (Sep 11, 2008)

I strongly recommend the 9speed Shadow derailleur for 9 or 10 speed road bikes running a large cassette. Yes, the housing is shorter but it makes a 90° bend instead of 180°.

They seem to have a stronger return spring than all other 9 speed mountain and 9 or 10 speed road derailleurs and the pulley more easily clears the largest cog. Working as a mechanic on tandem tours I deal with a lot of bikes running these drivetrains, mostly with Ultegra 10 speed or XT/XTR 9 speed derailleurs. Cable friction, stretch, and weight (cable couplers) is an extra consideration on a tandem and it's amazing how much snappier the upshifts are after I put a XT Shadow 9 speed derailleur on which allows me to not have to compromise the cable tension and downshifts. Whereas their original derailleur had the B-screw all the way in and the pulley nearly touching the largest cog the Shadow acheives perfect clearence with the screw in the middle of its range. Get'em while they last. I cleaned QBP out of 20 last month for our Europe tours.


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## aclinjury (Sep 12, 2011)

Lelandjt said:


> I strongly recommend the 9speed Shadow derailleur for 9 or 10 speed road bikes running a large cassette. Yes, the housing is shorter but it makes a 90° bend instead of 180°.
> 
> They seem to have a stronger return spring than all other 9 speed mountain and 9 or 10 speed road derailleurs and the pulley more easily clears the largest cog. Working as a mechanic on tandem tours I deal with a lot of bikes running these drivetrains, mostly with Ultegra 10 speed or XT/XTR 9 speed derailleurs. Cable friction, stretch, and weight (cable couplers) is an extra consideration on a tandem and it's amazing how much snappier the upshifts are after I put a XT Shadow 9 speed derailleur on which allows me to not have to compromise the cable tension and downshifts. Whereas their original derailleur had the B-screw all the way in and the pulley nearly touching the largest cog the Shadow acheives perfect clearence with the screw in the middle of its range. Get'em while they last. I cleaned QBP out of 20 last month for our Europe tours.


thanks for the input, very informative!

On a related note,
I was googling on ways to make shimano 10spd road shifters work with shimano mtb dyna-sys 10spd rear derailleurs, and I found this:

Jtek Shift Mate Straight 6 shifting adaptor - £29.99

it's basically a pulley device that alters the shift ratio of the dyna-sys derailleur so as to allow the RD to work with the 10spd road shifters. What a simply and ingenius little device. Apparently this company also makes a bunch of other similar pulley devices to make Campy/SRAM/Shimano shifters and RDs work together in all sort of combination. Very neat. Only problem the device is a little expensive at 30 British pounds ($46 USD). But this device opens up a whole new door to rear derailleur choices.


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## Lelandjt (Sep 11, 2008)

^Why bother? The last year of Shimano MTN 9 speed was the Shadow derailleur and it works just like the 10 speed Dynasys Shadow derailleurs except the cable pull is already perfect for your shifters. Now once they are all gone and all you can get is Dynasys I see the point but by then upgrade to Ultegra 11 speed. Those derailleurs take a 36t cog stock and 40t cog with a modification to how the B-spring sits in the B-knuckle.


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## bubba117 (Aug 20, 2012)

wolf tooth makes a hanger dropper so you can run a 36 tooth cassette. if you have issues look into that


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## looigi (Nov 24, 2010)

FWIW: As far as efficient cabling goes, it's not the length so much as it's the angle and radius of any bends. Fewer bends, lesser angle of bends, and greater radii generally lead to lower friction and less wear. With the closely spaced 180 degree turn from the chain stay to the RD that most road drivetrains have, the only thing you can do is reduce the radius of the bend by using a longer housing. The resulting bend is actually greater than 180 degrees as the cable first bends upward than down around to the back of the RD. Many mtb drivetrains have a 60 to 90 degree turn with a resulting reasonably large radius. 

With externally routed shifting cables I'd usually only replace the rear loop to restore rear shifting performance. With the extra sharp turns added by routing them under the bar tape, that no longer works.


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