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Shimano 105 front derailleur troubles

I just recently bought a bike (defy advanced 2), and noticed some chain rubbing on the front derailleur. I watched some videos and unscrewed everything to try and adjust it, I noticed I was missing the support plate as my derailleur is the brazed on version. The seat tube on my bike is D shaped and I noticed when I screwed the support screw out it ended up at the corner of the seat tube, so the plate would have to be at a 45 degree angle. The tough thing is every guide to setting up and adjusting the front derailleur includes the support plate adjustment which I do not have. Can anyone weigh in on this? Is this a normal thing and do I absolutely need this plate? I'll include some pics. Thanks for any help!

Pics: https://imgur.com/1mLsG7c https://imgur.com/mLGVQNK https://imgur.com/zUSsYrg

Posts

  • You don't need the plate, it is to aid shifting from small to big ring but doesn't affect chain rub, have you got the trim functions set right?. Shimano derailleurs have a trim function to stop chain rub, that's why there are 4 clicks on the left shifter. If you are in the big ring and then move the shifter again in the same direction the derailleur moves out slowly, and also when you shift to the small ring if you then press the small shift lever again the derailleur will move onwards again to eliminate chain rub. This is assuming the derailliuer has been set properly with the limit screws and cable tension
  • You don't need the plate, it is to aid shifting from small to big ring but doesn't affect chain rub, have you got the trim functions set right?. Shimano derailleurs have a trim function to stop chain rub, that's why there are 4 clicks on the left shifter. If you are in the big ring and then move the shifter again in the same direction the derailleur moves out slowly, and also when you shift to the small ring if you then press the small shift lever again the derailleur will move onwards again to eliminate chain rub. This is assuming the derailliuer has been set properly with the limit screws and cable tension

    I've been at it for a while trying to properly set it up. I have noticed the trim function and I've been following videos. My main struggle is figuring out the placement of the actual derailleur and the position of the L and H screws so that the chain actually shifts when I'm all said and done. I appreciate the reply!
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