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Shimano Ultegra Crank Metallic Rubbing Noise

I upgraded recently to a Shimano Ultegra groupset on my 2003 Bianchi Giro aluminum frame with Bontrager Aeolus 3 wheelsets (rim brakes). When grinding, I hear a metallic rubbing sound coming from my right crank, between 4 and 6 o'clock. This only happens on the right crank and only under pressure. There is no play in the crankset - everything is tightened appropriately.

This noise sounds like something a rubbing disc might make, but I have no discs on my bike. It happens regardless of the chainring (52/36) I'm riding on. I took my bike into the shop – they said they couldn't hear anything (did they even try to pedal under heavy load?).

Any ideas on a cause? Thanks in advance.

Posts

  • First.AspectFirst.Aspect Posts: 7,186
    Could be referred noise (ie it only sounds like it's coming from the crank) could be a bearing (BB or perhaps a pedal) or could be the crank itself is starting to go. Easy to spot the last one - there would be the beginning of a step between the chainring and the crank. There's loads online about this happening with hollogram cranks.
  • Thanks. The BB and crank and pedal are brand new (January 2021).
  • First.AspectFirst.Aspect Posts: 7,186
    Obvious question, but is the front mech set up right?
  • Here's my limitation - I don't know if the bike shop "did it right." Is there any way of knowing by simple observation without disassembly? Photo attached of right crank/BB (crank at 4 o'clock position).


  • webboowebboo Posts: 3,759
    Does the chain rub on the front mech.
  • MattFalleMattFalle Posts: 5,536
    have a good look at crank arms, bottom bracket and front mech - if anything is rubbing you'll see marks from it.

    if all is rub mark free then its time to look elsewhere.

    can you put it on a turbo trainer, get someone to ride it so you can have a look?
  • The chain is not involved here. I see no rubbing anywhere. A mystery.

    No trainer to observe, unfortunately.
  • First.AspectFirst.Aspect Posts: 7,186
    What are we supposed to be looking at in that photo?
  • I was just offering that up to show that everything looks normal - and yet it's not normal.
  • MattFalleMattFalle Posts: 5,536
    absence of the normal, presence of the abnormal.
  • i.bhamrai.bhamra Posts: 175
    Sorry in advance if I'm telling you things you already know or have tried.

    I'd take the crank out and give everything a clean and re-grease and put it back together and see if it's still there. Did you put in a new BB (I would if not), also make sure you don't do the pre-load up too tight, it only needs to be tight enough to fully seat the NDS crank arm, you can even back it off some once everything is in place, the clamping force comes from the two bolts in the arm.

    Also another quick thing to check is whether all the chainring bolts are tight.
  • Thanks! The BB is new. I'll give your suggestions a try and see what I find. Thanks again!!
  • pilot_petepilot_pete Posts: 2,098
    Ensure your quick releases are tight. If not you can get a noise from the dropout which resonates through the frame/ fork, especially when honking on the pedals, which is often thought to be from the BB, but isn’t.
  • rob.mrob.m Posts: 88
    Try tightening up your cleats.
    It's never too late to become what you might have been...........
  • darkhairedlorddarkhairedlord Posts: 7,017
    Oil the bar end plugs.
  • First.AspectFirst.Aspect Posts: 7,186
    Wear knee warmers.
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