mystery front shifting problem

yadn Posts: 11
edited November 2013 in Workshop
hey all

I recently took off my cranks to clean and grease the bearings on my hollowtech 2 bb

everything fine and dandy until 10 miles into first ride when the chain stopped shifting onto small chainring - even with all tension let out the cable and the limit screw all the way out.

as far as I can see the bearings, axle and preload cap are all fine, without too much wear and properly installed.

cannot figure out what is going on

anyone ever had a similar problem?



  • diamonddog
    diamonddog Posts: 3,426
    Is derailleur moving freely or is it sticking possibly?
    I had this on my turbo bike and it was the derailleur that was gunged up and not moving freely.
  • yadn
    yadn Posts: 11
    the derailleur seems to be moving fine. I've given it a clean down and bit of lube - I think it's reached the limit of how far it can move into the frame.
  • JayKosta
    JayKosta Posts: 635
    Perhaps a piece of 'gunk' has gotten between the tip of the limit screw and the 'swing arm'.
    Or maybe something is wedged elsewhere that is preventing the cage from moving more inward.

    Jay Kosta
    Endwell NY USA
  • mattv
    mattv Posts: 992
    Or the front mech has been knocked or twisted?
  • yadn
    yadn Posts: 11
    cheers for the suggestions so far...

    I'll take the mech off the frame tomorrow and have a close look at it.