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Shifter/Der issues

JRogers

talks too much
Mar 19, 2002
3,789
1
Claremont, CA
On my Tomac 204, I ran a road cassette (27 top gear I think) with a Dura Ace rear der. and XT trigger. All 9 speed. Worked fine

I transferred all the parts to my Mountain Cycle 9.5 but switched the cassette to a 32T max. At first, I had trouble shifting into the lowest 2 or so gears. I figured i was the chainguide so I spaced it out and it was better but I still had issues. Now, the lowest 3 do not work properly (in the third it gets there but skips, cannot get to the lower 2 at all). It's not the limit scew (I took it out and the problem persisted) or the tension (downshifts on the first click). Adding b-tension does nothing.

I replaced the der with a 105 thinking something maybe was bent (still short cage) and now the highest gear does not work (der does not reach it, no matter where the limit is and with no cable tension at all). The der also does not reach the lowest gear (the shifter shifts to it but the der doesn't move; in the shifter, it feels the way it would if the limit was too far in....but the limit screw isn't changing anything).

I am sure I am turning the right scews. The hanger appears perfectly straight. I took the wheel out (12x135mm), checked it, made sure the cassette was tight and reinstalled.

Any ideas?
 

stratguy1618

Monkey
Apr 18, 2004
252
0
Maybe you could see if the chain is the correct length, that could be the problem, might wanna add/take off, a few links.
 

JRogers

talks too much
Mar 19, 2002
3,789
1
Claremont, CA
stratguy1618 said:
Maybe you could see if the chain is the correct length, that could be the problem, might wanna add/take off, a few links.
Chain length is fine. If the chain were too short, it'd be easy to see. Too long and it'd be dragging on the der.
 

JRogers

talks too much
Mar 19, 2002
3,789
1
Claremont, CA
PsychO!1 said:
Are you using a new cable and housing??

I found cables issues to be the root of 99% of all shifting problems.
Housing and cables are old and worked fine before. Problem is that even without the cable attached, I'm not getting full range.
 
JRogers said:
Housing and cables are old and worked fine before. Problem is that even without the cable attached, I'm not getting full range.
Well, the road der. your using can't handle the big cogs your running. Max is 28 I think.
That would explain issues at that end of the cogset, don't know what's up with the small end though.

[edit] I would still put new cable and housing on....it's just a good idea.
 

Jeff 151

Monkey
Sep 25, 2004
176
0
DeezBay, Cali
Short cage (road) rr derailleurs do not work on full-spread mtn cassettes, not in a million years. Go back to the tighter cluster or get a long cage.
 

zahgurim

Underwater monkey
Mar 9, 2005
1,101
12
lolAsia
I run a shortcage Dura-Ace with an 11-32 on two of my bikes, awesome shifting no prob. Roady mechs can work, and it shifts better than anything else I've run.

9 speed is 9 speed, the cassettes are the same width. With nothing limiting the derailer, it should at least go through the full range of width. If the derailer is not going through the full range even without limit screws, and no cable installed, the only thing I can think of is frame interferance. Check to see that the derailer cage is not hitting the underside of the swingarm, as it happens on some frames...
If it is frame interferance, you might be able to solve it by tightening your chain , as a tighter chain will put more tension on the derailer cage and alter it's position a bit. But be carefull, as you are running a long-travel bike, and you want enough chain to go through all of it...
Getting a roady mech to work with a large range cassette is a bit of trial and error, but works great if you can get it to work.

good luck!
 

JRogers

talks too much
Mar 19, 2002
3,789
1
Claremont, CA
I still can't figure this out. Not a big deal; I am just running a 7 speed now and it shifts fine. I knew that the road mech would work on the 32 because I've done that before, even with a front ring. Shimano is cautious about their recommendations.

I think I might take it to the shop or see if Shimano wants to look at it at Mt Snow if they're there.
 

Wumpus

makes avatars better
Dec 25, 2003
8,163
154
Six Shooter Junction
JRogers said:
I am sure I am turning the right scews.
I'm sure you are turning the right screws, but I've been known to get them backwards frequently:

H adjusts for the smallest cog and L adjusts for the biggest cog.

It is the only thing that I could imagine would be causing it.
 

Biscuit

Turbo Monkey
Feb 12, 2003
1,768
0
Pleasant Hill, CA
It could be your new Mountain Cycle spaces the der farther away from the cassette than your Tomac did. Therefore, the knuckles on the road der simply can't reach far enough.
I had a problem similar to this on my v-10 and solved it by taking the short cage off the Ultegra, and placing it on an old XT knuckle assembly. It's pretty easy, just remove the set screw and slide out the cage.