Forum menu
Front mech..what am...
 

[Closed] Front mech..what am i doing wrong?

Posts: 160
Free Member
Topic starter
 
[#4185338]

So i cant get the middle ring to index at all..how do i sort it? The inner and outer rings shift fine, but shifting both up and down the chainset, the shifter seems to ignore the middle ring completely... ive tried adjusting the cable and the barrel adjuster but no luck as yet. Any ideas?


 
Posted : 22/07/2012 7:01 pm
 GW
Posts: 0
Free Member
 

the shifter determines how much cable pull between gears which determines how far the mech swings.
is your shifter knackered?
or do you have a shifter with incompatible cable pull for your mech?

You really need to give far more info to find your answer.


 
Posted : 22/07/2012 7:15 pm
Posts: 160
Free Member
Topic starter
 

Cheers GW..its an LX Shifter (M580), SLX front mech (M660-10) and LX Chainset (M580). It seems as though the shift doesnt want to stop at the middle ring, as though there is too much leverage being applied in the shifts. The routing is correct - top route, the bike is an OnOne 456. Any ideas?


 
Posted : 22/07/2012 7:32 pm
Posts: 5559
Free Member
 GW
Posts: 0
Free Member
 

does your shifter have 3 distinct clicks? (well.. 2 going each way)?


 
Posted : 22/07/2012 8:05 pm
Posts: 598
Full Member
 

Start at the beginning

Set the mech straight and true

Set yout h & l limiters

If its and old cable/outers then change them

Make sure on the granny ring you are in te lowest on the shifter

Tension the cable correctly and away you go

Had mine in bits today

It's easy


 
Posted : 22/07/2012 8:51 pm
Posts: 0
Free Member
 

It does sound like a double front mech changing on a triple.


 
Posted : 22/07/2012 9:15 pm
Posts: 598
Full Member
 

Disconnect the cable from the mech and hold the tension with your finger, shift and detect three points of movement


 
Posted : 22/07/2012 9:18 pm
Posts: 160
Free Member
Topic starter
 

Ok folks, the front mech is definitely for a triple chainset, and yes, under tension, there are 2 distinct clicks from the mech when shifting up and down, the stops are setup correctly, new cables.....and still no luck. Ive set loads of these in the past, never had an issue, but this one is driving me nuts..any more ideas?


 
Posted : 23/07/2012 7:25 am
Posts: 160
Free Member
Topic starter
 

One other thought..the mech is a 10 speed, but the setup is 9 speed. Would that matter? I was advised by On One (i bought the mech from them at the same time as the frame) that they were fully compatible.


 
Posted : 23/07/2012 7:39 am
Posts: 0
Free Member
 

I have a feeling Shimano changed the cable pull on the front mechs too with Dyna Sys.


 
Posted : 23/07/2012 8:40 am
Posts: 160
Free Member
Topic starter
 

Ive figured the problem...its basically the wrong type mech..(/sarcasm on)cheers OnOne for your fantastic advice(sarcasm off/)! Ive just taken the mech off my Crush (the Top Swing type) and hey presto, it works immediately! A PITA but at least it was relatively simple in the end.


 
Posted : 23/07/2012 8:46 am