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Faulty Bottom Bracket Shell

bongobigginsbongobiggins Posts: 36
in Workshop
Hi guys

Noticed a creaking from bike, checked all usual suspects before removing the bottom bracket.

Not sure if you can tell from the picture but there is a groove running around the shell.

Just wondered if anyone had experience with something like this before and if this would be cause of said creak? The creak gets worse with more power.

I have already emailed frame manufacturer and am awaiting reply. Bike is less than a year old and has only done around 2k miles.

Any input would be appreciated.



Posts

  • thecycleclinicthecycleclinic Posts: 394
    The groove is not necessarily a fault. A customer wanted to return a bb that started to creak
    First it's used. Second I suggested the creak may not be the bb. He said he checked everything GM j said assume nothing. That's wise.

    He got rid of the creak by putting ptfe tape on his left pedal thread.

    Never assume.

    I have a creak kn my look 795. It though it might be the bb. It's not. Its something else. Pedals, chai ring bolts, cleats take your pick. If I find 20 minutes I'll sort it out hopefully.

    Never assume with bikes.
    www.thecycleclinic.co.uk
  • bongobigginsbongobiggins Posts: 36
    I've tried with a different crank set and pedals. I've serviced and torqued everything, even the bottle cage bolts.
    Tried a new bottom bracket and still get the creak so I'm not really sure what else it could be.

    Its rideable just extremely annoying. Also don't want it to get worse, which I feel like it has.
  • arlowoodarlowood Posts: 2,551
    BB creaking is normally associated with press-fit BB's where there is a reliance on very fine tolerances on the BB shell to ensure that the press-fit bearings are accurately seated with no potential for movement under load.

    Your BB has a threaded insert that appears to go a fair way into the shell and should be tightly bonded with little or no room for slight movement which would result in creaking.

    As @cycleclinic says there is probably another source for the creaking that you haven't yet eliminated. For example you mentioned trying different pedals but have you tried swapping cleats.
  • flasherflasher Posts: 1,734
    QR's?
  • Darius_JedburghDarius_Jedburgh Posts: 675
    I've just cured a damed annoying rattle from my bb area. I took my bottle cages off to wash them. Bolts were a touch loose. Washed and refitted tightly and the rattle has gone.

    Noises come from unexpected sources.
  • racerexracerex Posts: 66
    Hard to tell what I'm looking at. Is it a "groove" or are there two pieces pressed together? Might help to know what make/model of frame. If it's just a groove cut into the face of the shell it probably happened when torquing the bottom bracket. Take it to a decent LBS and ask them to properly face the shell.
  • masjermasjer Posts: 1,892
    If you've tried all the main culprits for creaks, another place to look is the rear mech hanger. They can creak against the frame. Remove, clean, silicone grease the mating surfaces and reinstall.
  • me-109me-109 Posts: 1,730
    I traced a creak on mine to a rusty nut on the rear brake mounting. Didn't show so much on the road but on the turbo with a captive back end it was really bad. The rust made the nut swell to fill the recess in the frame.
  • bongobigginsbongobiggins Posts: 36
    Thanks for all the input.

    I narrowed it down to coming from the rear area. Redid the hub, rear derailleur and hanger, creaking has gone for now.
    Not exactly sure which it was but went out for 4 hours this morning and all is good.

    Aside from that is the groove on the shell anything to worry about in the future?
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