Difficulty adjusting front derailieur

[Deleted]

I have since learnt, that I should have just "trimmed" the blasted thing using gear adjustments near handlebars, but reduce some of the rubbing, I adjusted the screws, which didn't work, so thought I'd adjust cable tension. Put it back together and now cannot get my front derailieur cage to shift at all (although shiftable if I move cage with my hand).

I''ve tried youtube, sheldon brown, my bike book, and swearing at the thing, and nothing works. They all tell me to put it in the big ring to adjust it - but I can't get it there!

How on earth do you get a now not functioning front derailieur to go back to a previously healthy front derailieur (that rubbed on the cage a bit)?

I'm sure this is perfectly simple, but mechanics do not come to me naturally!

[Grae]

I don't understand why they're telling you to put the front mech in the big ring position. It's natural state (least tension in the spring) is in the small ring. Unscrew the cable at the derailleur again (ensuring the mech takes up the small-ring position), and make sure the sti lever is where it should be for the small ring also. Pull the cable from the loose end (taking out the slack and making sure it's still going under the bottom bracket) and then feed back into the derailleur clamping screw thingy and tighten. Then you can fine tune things with the adjuster screws.

[Deleted]

As Graeme indicates but also the chain must be on largest rear cog so that the derailleur does not rub when on the small ring. Adjust the bottom stop screw to move the derailleur inner plate BEFORE attaching/adjusting the cable. Manufacturers indicate exact gaps between derailleur plates and chain. Once the plate is adjusted It is important that the cable is then pulled bow tight when the derailleur is in the relaxed, least tension position and the sti is in lowest position, clamp the cable when sufficiently taught. This will reduce cable stretch when you change up. As you change up the cable becomes more taught as the derailleur moves up to the big ring and hence the ability to overcome the spring tension. It is this spring tension which allows the derailluer then to 'drop' when changing down. The other stop screw should be adjusted so that the outer plate does not move much beyond the big ring when changing up. This will give you a wide range of rear cogs on the big ring without chain rub. Again the manufacturer states a max gap.

¬¬¬

[Deleted]

Thanks for your help - it transpires that the problem was actually that I'd sent the low gear as the highest gear, so it wouldn't shift up any further.

Simple when you know how!

[andyw]

when in doubt: www.parktool.com/

[Deleted]

Feb 24, 2009 19:51:56 GMT @melissa said:

...
How on earth do you get a now not functioning front derailieur to go back to a previously healthy front derailieur (that rubbed on the cage a bit)?

...

Just phone your mechanic and get him to sort it out, seems to work most times