[GoatPiper]

I've been having problems with a front derailleur that isn't shifting properly to the largest chainring. Instead of shifting the chain up and onto the large chainring, it just jams the chain against the inside of the chainring. I have tried various adjustments to no effect. What does it sound like the problem is?

Thanks

 

[indieboy]

Originally posted by GoatPiper
I've been having problems with a front derailleur that isn't shifting properly to the largest chainring. Instead of shifting the chain up and onto the large chainring, it just jams the chain against the inside of the chainring. I have tried various adjustments to no effect. What does it sound like the problem is?

Thanks

it's probably not sitting at the proper height. probably what is causin the chain to get jammed instead of pushing it up onto....

 

[Rev.Chuck]

As indie boy says set you height first. You want the der. to clear the big ring by about 2mm. Have the der. in line with the chainrings to just a little tail out.
Another problem could be if the der has a lot of use it can burr up on the inner plate and hold onto the chain rather than letting it slide up
And, if you have swapped to a bigger chainring (the jump is 32-44) and the new ring is not ramped you might have to shift easy and or tweak the inner plate to angle it so that it helps lift the chain.

 

[Rustmouse]

to adjust height, you literally loosen the derailleur mount and slide it up or down on the post until you get the magic 2mm clearance.

the other thing to check, the cage alignment, is also altered by moving the mount. I've found its easiest to loosen the der mount, adjust the height (you might have to disconnect the cable depending on the style you have, it keeps pulling the der out of position). Then tighten the mount some and adjust it so that the cage is parallel to the chainline or slightly tail out. (watching that the height remains the same.) tighten it down again, adjust the cable tension (it's going to change when you adjust the der. like that) then adjust the der and check it out. If it's not solved, you may have a bent cage, damaged chainring, or other issues.