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Strange Noise from B/B or crankset

giantjasongiantjason Posts: 89
edited September 2007 in MTB workshop & tech
I have a strange noise that appears to be coming from my crankset/bottom bracket.

Each time i pedal i get a clicking noise on every full rotation of the pedals?

Any ideas what this is?

If i need a new bottom bracket/crankset i will replace the whole lot. Is it a simple matter of un-doing the b/b and cranksets and replacing?

Cheers

Posts

  • SplasherSplasher Posts: 1,528
    First remove your pedals and grease the threads and the flange and re-assemble. This is often the culprit where a click is concerned.

    Otherwise it could be your chainring bolts or failing that a dry connection between your cranks and your BB.

    If you do decide to change, it is just a case of undoing and replacing but you'll need tools to do that like crank pullers and various BB tools depending on what you've currently got.
    "Internet Forums - an amazing world where outright falsehoods become cyber-facts with a few witty key taps and a carefully placed emoticon."
  • giantjasongiantjason Posts: 89
    i have tried removing my pedals and replacing them but the noise is still there. i have also checked and tightened all the chainring bolts.

    It only occurs when the pedals are under load and comes and goes.

    Yesterday i did 25 miles off-road and did not hear it once. I washed my bike last night and then on my way into work this morning it started up again.

    How would i check if it was a dry connection between cranks and BB and what is the best way to lubricate this?
  • deanvwdeanvw Posts: 412
    mine does the same, but i found out that it was the hub -not the bb, i found this out by taking the rear wheel off and spinning it and it made clunking noises
    http://mtbdean.pinkbike.com/

    Kona Scrap
  • nicklousenicklouse Posts: 50,675 Lives Here
    read the diagnosing drivetrain noises part of parktools. linky bellow.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • skylinerskyliner Posts: 613
    Tighten your rear QR skewer.
    It's nice to be important, but it's more important to be nice.
  • deanvwdeanvw Posts: 412
    it aint that, i think grit has got into my hub, i might have a go at doing a service to the hub thanks to parktools
    http://mtbdean.pinkbike.com/

    Kona Scrap
  • skylinerskyliner Posts: 613
    If it's only doing it under load, you'll need to get a new freehub. it'll be a shot pawl. The next step is a locked cassette, or zero drive.
    It looks like you've got a M475 hub. If so, you'll need the C201 freehub. Cost about £18.
    It's nice to be important, but it's more important to be nice.
  • deanvwdeanvw Posts: 412
    nah its a promax
    http://mtbdean.pinkbike.com/

    Kona Scrap
  • giantjasongiantjason Posts: 89
    no it is not the rear hub as it is still there when i change over to my skinny commuting tyres on seperate wheels.

    i dismantled my pedals and cranks and greased them put them back together and it still sounds everytime when my left pedal is at approx 11 o'clock when pedalling along.

    is there a way to lubricate the BB?
  • SplasherSplasher Posts: 1,528
    Yep, which BB is it?
    "Internet Forums - an amazing world where outright falsehoods become cyber-facts with a few witty key taps and a carefully placed emoticon."
  • giantjasongiantjason Posts: 89
    i think it is a shimano BB. It is on a giant terrago disc 2005.

    Underneath there appears to be a small hole in the frame directly below where the BB is.

    Do i need to take it apart to lubricate it?
  • supersonicsupersonic Posts: 82,708 Lives Here
    The hole is for drainage, or to screw a cable guide into.

    You need to remove the cranks, the bottom bracket, clean the threads and use copaslip or teflon grease om the threads. For info on how to do this, there is an article in park tools. Did you read the geberal clicks and creaks article? Could also be chainring bolts. Also if your axle is square taper, it should not be greased, its a dry interference fit.
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  • giantjasongiantjason Posts: 89
    what tool do i need to remove a shimano bottom bracket.

    My axle is the square taper type.
  • nicklousenicklouse Posts: 50,675 Lives Here
    a shimano bb tool. and a crank remover.

    have a look on parktools for tool info and how toos.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Al_YatesAl_Yates Posts: 3
    You could also take your bike into the bike shop and get it "Faced off", This cleans the threads and gives them a perfect match then clean and grease. It will help...
  • nicklousenicklouse Posts: 50,675 Lives Here
    Al_Yates wrote:
    You could also take your bike into the bike shop and get it "Faced off", This cleans the threads and gives them a perfect match then clean and grease. It will help...

    sorry to pull you up on this Al but you are getting two things mixed up.

    you can have your bb threads "chased" which the cleaning and reshaping of the threads that is done with two thread taps. then there is having the bb shell "faced" which makes sure that the two ends of the bb shell are perpendicular to the center axis of the bb cup.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
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