Front Mech Problems

[User]

 

[mjr]

Measure how much cable it pulls on each click and compare it with published specs. It may be a mismatch between shifter and mechanism, or a defective shifter as you suspect.

I don't know that exact model but I've dismantled some shifters and some needed four hands (thanks to the expert who helped, if he reads this!) and many many tries to reassemble, but no special tools.

 

[I like Skol]

With the cable disconnected from the mech are you getting the three positions of the cable pull (i.e position 1 is the start then 2 clicks to give position 2 & 3)? If you are then it probably isn't the shifter at fault. Try unscrewing the stop screw for the large chain ring a couple of turns to see if this gives you the 3rd position, it could be that you are hitting the stop screw before the shifter reaches the 3rd click. If this is the case then it could well be a mismatch between shifter and mech or maybe the cable is clamped wrongly at the mech, Make sure the cable passes to the outside of the clamp bolt.

 

[Ajax Bay]

I think it's unlikely to be a mismatch between shifter and FD: the Alivio is for an 'MTB' and the fitted (assumed original) FD will be too. Iterative adjustment, albeit frustrating, if necessary from scratch. Cable off; adjust limit screws etc.

 

[mjr]

I think it's unlikely to be a mismatch between shifter and FD: the Alivio is for an 'MTB' and the fitted (assumed original) FD will be too. Iterative adjustment, albeit frustrating, if necessary from scratch. Cable off; adjust limit screws etc.

Unlikely but there's little harm in checking (and assume as little as possible!). If the mech isn't shifting properly, it's easiest to disconnect the cable to measure the pull anyway, so it can be reindexed from scratch after.

 

[Tim Hall]

I had what might be a similar problem with a front mech shifter that had lain dormant for a while, such that it wouldn't give a third "click". Removed the teeny screws that held the cover on, cleaned off the gunked up grease on the internals (a plastic spring IIRC) and reassembled. All good and no powerful spring inside to attack the unwary.

 

[Ajax Bay]

As @Tim Hall suggests, a good spraying with WD40/GT85 in there may well sort it (and is worth doing occasionally anyway, just through the orifices).

 

[Tim Hall]

[QUOTE 4234663, member: 9609"]with the cable disconnected, there is full range of movement at the dérailleur.
with the cable disconnected I can only get one click at the changer, I can not get the little green thing to move to Position.3
[/quote]

That sounds like the problem I had. The lever wouldn't engage on the internal gubbins, so the indicator didn't move and the lever was a bit floppy.

 

[Ajax Bay]

@Tim Hall on the money. Glad OP could sort it and hope his brother appreciates the effort and tlc that the bike has had invested in it.