front mech movement

[afl2]

i have a triple front and i can move the chain from middle to large ring but not back. I had to stop and manually do this and now having tried again the same happens.
Can i assume that the cable has stretched and that i will need to replace the cable?
Using the shifters it will not go from middle to small either.
thanks

 

[jonathanw]

it may be that your front mech has seized, as mine did recently, most likely due to the road salt and dirt from winter riding. Down shifting loosens the cable and allows the spring in the mech to return it to the position it wants to be in. Tightening the cable will help up-shifting. Your symptoms, needing to manually down shift, suggest a seized mech

There are many solutions to try and un - seize a front mech such as immersing in parrafin or petrol then re-lubing, but they may never return it to good working order. I just replaced my tiagra front mech for £15

 

[qwiksilver]

usually if stretched it will have some movement so when you go from mid to top it should go bk down to mid or atleast try to dose it move at all when changing down?

 

[afl2]

no it does not move at all.

 

[qwiksilver]

release the cable from the mech and see if the mech moves freely (can be misleading as it may move under your force but not that of the cables)so hold the cable under tension and shift see if the cable pulls your hand if the cable moves in your hand its the mech if not then its that cables or shifter process of elimination with guide you to the problem

 

[afl2]

thanks the cable moved but not the front mech

 

[jonathanw]

It does sound like it is seized.

Take it off and immerse it in paraffin or petrol for a few hours and see if the movement frees up and then re-lube with 3 in 1. That may work, but I suspect you'll need a new one if properly seized

 

[afl2]

ok thanks. will try.

 

[afl2]

Update. Did as recomended with the help of a friend, Took off the front mech and soaked in spirits. This cleaned up well and moved alot easier. Reassembled with a lot of help from friend!! and cable attached and mech aligned and all is now well. Thanks for youe advice.

 

[jonathanw]

Excellent news.

Front mechs can be awkward to refit. I'm glad it was salvageable.