Fitting front derraileaur-Fools guide

markjohnwood

Hi people,

Looking to fit a Deore front mech 9spd to my mtb, currently has an Alivio mech. Looked at how to vids but can only find adjustment videos. How easy is it to unhook one and fit the other and any advice??

Cheers

nicklouse

have you looked at Parktools?

have you read shimanos instructions that come with it (it covers fitting and adjusting)

one bolt for the cable and one bolt for the clamp.

jimothy78

Pretty straightforward. They're all pretty similar, and if you're replacing with the same type (ie. same clamp position and pull-direction) then it's simply a case of releasing the cable-clamp and clamp-band bolts, remove the old one, install new one in same position and install new inner cable and then sort the indexing. Worth replacing the cable outer as well, unless you've done it quite recently.

markjohnwood

Soooooooo not so easy!!

I've got the derailleur in place and working when indexing gears but I can't get either the H or L screws to do anything, I need to move it out to get full purchase to move chain onto big ring but there is nothing when I screw either in or out - HELLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLPPPPPP!!!

jimothy78

The limit screws won't do anything if the cable is holding the mech in a position between the limits they're currently setting. Basically, they won't appear to have any effect if you try to adjust them at the wrong time in the process.

Release the cable clamp, and the mech will move back all the way to the lower limit. Screw the L screw IN and eventually you'll feel it make contact and start to push the derailleur cage outwards if you continue turning it. Set it so it's just missing the inside of the chain when in bottom gear (smallest front, biggest rear). Then connect the cable as tight as you can by hand (without actually moving the derailleur cage)and take up any slack with the barrel adjuster. Then shift into top gear (biggest front, smallest back) and screw the H limit screw in until the the cage is just missing the outside of the chain. Last of all, set the tension through the barrel adjuster so that the chain shifts smoothly onto the middle ring from both of the others.

cooldad

Or read Parktools. (refer post 2)

The Rookie

You'll almost certainly have to split the chain as most front mechs these days are rivetted and not bolted!

markjohnwood

Jimothy - Thanks that makes sense will try going back to start and refitting.

Nicklouse - Thanks used it but think I got a bit confused when fitting, easy when you get old!

Thanks everyone