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Posted (edited)

I do have a shifting problem on my bike.

 

It is extremely difficult to do up-shifts, I takes a huge amount of effort just to shift up. You need all the power in your fingers just to push brute force. Even without the wheel on just trying to shift the same problem.

What I have done for trouble shooting:

1. Checked the cable housings for any obstruction = nothing moving freely

2. Checked the rear derailleur spring = no extreme tension, derailleur clean of mud or any debris, the derailleur is only i year old do not do much riding.

3. Made a longer cable housing from the seat stay to the derailleur, thinking it maybe to short = no change. (see pic)

4. New shift cable was fitted in January.

5. Loosen the cable at the derailleur and shifting the cable moves.

 

Down shift no problems.

Components: Deore LX Shifters 9spd and Deore 9spd rear derailleur

 

Bought this morning a new cable and cable housing.

Shifter problem?

post-13049-0-64209300-1392111022_thumb.jpg

Edited by JJDT
Posted

I'm not a mechanic at all - but have you checked those limit screws? Could be that you are trying to force the derailleur past it's limit.

Posted (edited)

If you loosen the cable at the derailer and keep some tension on the cable with your fingers how does the shifting feel in the shifter unit, it should be easy to click your way up and down through the settings.

 

As above, have you checked your limit screws?

Edited by Mojoman
Posted (edited)

On a race, my water bottle spilled its 32Gi or whatever, which ran down to that little guide under the BB and gummed it up. Upshifts became virtually impossible. Check whether that's clean, especially if both derailleurs are giving problems.

 

Edit! Ah, whoops, I see your cable comes down the seatstay, not along the chainstay

Edited by LeTurbo
Posted

@gkp limit screws are correct

@Mojoman can feel the cable move shifting fine

@LeTurbo will check that out

@Tumbleweed just the angle of the pic

Posted

Firstly, it looks as if the cable housing is FAR too long for your bike - especially at the rear end, where it curves around to the derailleur. It should be a gentle curve, and hug the frame - not balloon out like it is at the moment. That will surely create some resistance. Also look at shortening it at the seat tube junction - also too long there.

 

Regarding the shifting - if it's shifting down (to smaller cogs) then it wouldn't be a problem of resistance. As you downshift, it releases pressure from the cable, and if there were any resistance it'd either take a while to complete the shift or not shift at all.

 

I presume there aren't any kinks in the cable, seeing as you've just replaced it with a new one, so that's not a problem.

 

The only other thing I can think of is that there's a problem with the shifter itself. If you've checked the spring tension, limit settings and so on of the derailleur, and it's operating normally when you use your hand to move it (no tough spots / sticky spots) then it can only be the shifter itself. Try to take it apart (if you can) and see if there's anything fouling the mechanism. May be a portion of the mechanism that's sheared off inside, especially if you've been putting a lot of force into it.

Posted

i've had a similar issue after a very muddy ride.

 

carefully open the shifter (2 screws at the bottom) spray some q20 in there to rinse out all the muck, let it dry and add a little grease.

 

try get the relevant service manual from techdocs.shimano.com. if you open the wring screw everything pops out and its impossible to put it back

Posted

I would say Your problem could be the shifter or limit on the derailleur , personally don't think it is the cable as there's no problem with downshifting , hope You come right .

Posted

Thanks for all the advice given my problem is sorted.

Last night opened the shifter to see if there might be a problem, noted nothing strange. There was no excessive dirt but cleaned it and added some oil.

Removed the "old new cable" and the cable housings and fitted the new cable and also shortened the housings as cpt armpies mayhem suggested.

First shifted without the wheel on and no problem. Fitted the wheel back on and also the shifting was smooth no force.

Will go for a short ride tonight to test.

Posted

Sweet. I've just thought of a possible cause - maybe one of the housing's steel cables (the ones that form the outer hard shroud) was exposed at one of the ends, fouling with the derailleur cable and only allowing it to move in one direction. Maybe. But if it's shifting without a problem now, then it was probably the housing causing the error, in some way/shape/form.

Posted

I'm pretty sure the cable was the issue. I had a similar problem after transbaviaans last year. All I did was take the rear wheel off, shift to the smallest cog, push the derailleur to the largest cog - this gives the slack to release the housing. Then moved the housing to another section of the cable, wiped, and lubed (finish line ceramic) and its been hundreds ever since.

 

Though mine started when I shifted in the middle of a river crossing probably "pulling" water into the cable housing.

 

Glad to hear you got sorted though.

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