I have set up a few front deraliuer in the past some using ultegra 6700, all of which ran without chain rub with the exception of the two expected cross chaining cogs.

For some reason on my new bike the available space in the front deraliuer seems limited when in the big ring in front.

The group set is Ultegra 6700. If I set the large ring in back and large ring in front not to rub on the FD, then the biggest 3 cogs in back will rub.

I know this is not normal. 2 cogs maybe but 3 seems too much. I have tried all combinations of cable tension and high limit screw in the FD.

I have noticed that there is slight lateral deviation of the large chainring about 2-3mm. I know there is suppose to to be about 1mm of chainring movement from side to side. I have removed the chain ring and tested with one from another bike which I know is straight. The issue remains, slight lateral wobble.

This leads me to believe it's the spider or the bb. Spider doesn't appear bent and bolts have always been tight. No lateral movement in crank arms which make me think it's not the bb.

Does any one have any advice or had a similar issue? Thanks in advance :)

  • Maybe silly but is it possible the FD got a little squashed and is narrower than it should be? – BEVR1337 Oct 20 '15 at 20:50
  • It's a fairly new group set. I guess it's possible, I'll measure the inner width to rule it out. Thanks for the suggestion. – Robaggs Oct 20 '15 at 20:58
  • I always like to start with the easiest possibility first! Probably not likely in this case but it happens to vintage sets and bikes. Good luck – BEVR1337 Oct 20 '15 at 20:59
  • Its possible its something to do with manufacturing tolerances of FD or frame. Ultegra 6700 on one of my bikes exhibits the same issue. – Andy P Jan 6 '16 at 11:58
  • Hi Robaggs - this question is old, and has no answer. Would you like to post and accept your own new answer describing how it has gone for you in the past 4 months? What did you find? – Criggie Feb 23 '16 at 7:32

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