Front derailer 101

[StevieL]

Hope someone here knows more about front derailers than what I do.

 

So I am getting "chain rub” on my front derailer on the big chainring (on the outside of the chain).

I know the H limit screw on the actual derailer will adjust the limit, but I think that is fine, because when I push the shifter, the derailer moves across far enough that the chain has about 1-1.5mm clearance.

My question though, is that when I release the shifter, the derailer moves back to the position that it is rubbing the chain. How do I make it stay in the outermost position, so as not to come into contact with the chain?

 

Edit:Spelling

Edited June 25, 2014 by StevieL

[droo]

Cable tension. Screw the adjuster barrel out a few clicks if you've got one, otherwise you'll have to fiddle with the tension at the clamping bolt on the derailleur.

[porqui]

droo - would an older cable have more "stretch" like a rubber bant in it?

[kennyg]

Single front ring, and toss it out.. best decision I ever made.

[dirtrider]

Single front ring, and toss it out.. best decision I ever made.

 

The second best decision you will ever make is to get rid of all that crap at the back as well .

[Old school]

Best way to adjust tension if there is no barrel adjuster, set the bottom limit screw to so the derailleur just touches the chain when configured with chain in small front chain ring and largest gear at the back. Then pull the cable very tight and re-tighten. The just touch of derailleur to chain should now be just mis on both ends of big and small chainring. Reset your top and bottom limit after doing this.

[Smartie]

Cable tension. Screw the adjuster barrel out a few clicks if you've got one, otherwise you'll have to fiddle with the tension at the clamping bolt on the derailleur.

+1 Cable Tension

[Johan Bornman]

No. Steel does not lose elasticity with age. Cables do wear down with time, become rough. Also, they file a shortcut through the bends and become relatively longer, compared to the housing because of the shortcut and that's when the adjustment goes awry.