Road mechs on mtbs

[dbmtb]

I ran 600 Ultegra rear mechs on the Dave Yates for a couple of years before it got the Sachs Quarz kit. I was already a retrogrouch when M739 came out
- it was due to not liking that groupset that I replaced my worn out M735 rear mech with the Ultegra one!

Still have one on the Stumpjumper, on which it is the only Shimano component.

 

[tintin40]

I ran a Suntour Superbe road mech. From memory it ran fine. I can't remember why i fitted it

 

[the_duke]

I have been experimenting with a dura ace mech on my Overbury's, I had seen gravymonster using a 105 and liked the look of the short cage. I also disliked the colour of m950 and this model da (7700) was about the right time for my frame.

It is a very short cage and I find works best with a double at the front. It will work with a triple but only if you dont use the extreme gears. I like the flexibility of being able to use big big, small small . . . . . . . . read lack of ability

 

[Augustus]

Yup, put a 105 on my Trekker in 89/90. It was cool wasn't it.

Just put a 10spd Ultegra SL on my Merlin. Cos it matches the colour of the M960 XTR and, again, it's cool isn't it?

 

[kikideparis]

always use short cage mech because it's allows more clearance in woods and road mechs are shortest. have a old 105 on my latest parkpre built

 

[paininthe]

Then... there is always the option of fitting the cage from an M95x XTR to a Dura Ace 7700

Are they a straight swap?

 

[cce]

i've never actually tried it, but i think the fitting method is the same

 

[Kentphil]

I've been considering doing this for a while, and changing to a double chainring at the front on my "commuter" MTB

 

[MikeD]

Does chain length actually have anything to do with it?

It's the difference in length between the extremes. On a trad MTB it'd have to accommodate everything between 46/28 (tight chain) and 24/12 (baggy chain). That's a bigger difference than between 52/25 and 39/13 or whatever on a road bike. Longer cage takes up more slack.

 

[andrewl]

Seeing shogun's pic on the June (ahem) coolwall reminded me of the little craze early/mid 90s for fitting road mechs on mtbs.

It looked nifty but the cages weren't really long enough, are the cages not shorter than a mtb short cage? Had a 105 road mech on my 1991 (ish) Stumpy for a while. Who else did this?

Only some minor points, the craze goes back to the mid/late 80s - my 89 Toad has had one since it was first built up and there are other earlier bikes which were built with short cage road items too.

With respect to cage length, short cage MTB rear derailleurs are quiet rare. Shimano made some short cage (SS) version of the M950 for DH only applications its quite rare to find one of these. Commonly the shortest cage MTB rear derailleurs are mid cage (GS) and are the same length as a mid cage road version (as you'd expect). Long cage are SGS (in Shimano speak).

Anyway a short cage road derailleur works perfectly well and does give better clearance in tricky conditions, the trick to making them work (with a triple) is running a shorter chain which prevents you cross chaining (ie big big). The only issue I've ever had is with mud on the "aero" road versions like the Shimano 600 on the Toad.