Strange Noise under Load

Discussion in 'Cycling Equipment' started by starship, Jun 20, 2004.

  1. starship

    starship New Member

    Joined:
    Jun 16, 2004
    Messages:
    168
    Likes Received:
    0
    Cannondale R800, S105 geartrain. Sometime under LOAD I get a strange noise from my rear end (the bikes!). Its almost a click and almost a thump and almost a grind. But only when I getting on the pedals and pumping hard.

    ANY SUGGESTIONS WELCOME! PLEASE!
     
    Tags:


  2. nmacturk

    nmacturk New Member

    Joined:
    Jun 20, 2004
    Messages:
    1
    Likes Received:
    0
    I had a similar problem and it was caused by the bottom bracket. When it was replaced the noise went away.
     
  3. starship

    starship New Member

    Joined:
    Jun 16, 2004
    Messages:
    168
    Likes Received:
    0
    Bottom bracket? The supports for the bottom chain pulley?
     
  4. drewjc

    drewjc New Member

    Joined:
    Jun 5, 2002
    Messages:
    327
    Likes Received:
    0
    Bottom bracket is the axle and bearing assembly that supports the cranks (the bits with cogs on them that u pedal with). There is often some minute amount of movement in this area and i have heard that especially in Cannondales due to their large section tubing, they resonate the sound a lot sompared to some other brands. If this isnt the case i just had a thought that it may be the replaceable tip (the part u bolt the back wheel on to) may be a bit loose, or sometimes the Quick Release skewer is not quite tight enough and this causes a grinding/squeaking noise to resonate throughout the frame. Good luck.
     
  5. ed073

    ed073 New Member

    Joined:
    May 19, 2004
    Messages:
    1,528
    Likes Received:
    0

    True....Cannondale tubing acts like an echo chamber. Little creaks and clicks are amplified to sound like your frame breaking in half. :D
     
  6. jrandolph

    jrandolph New Member

    Joined:
    Jun 20, 2004
    Messages:
    2
    Likes Received:
    0
    Bottom bracket all the way!



     
  7. rmartin

    rmartin New Member

    Joined:
    Nov 26, 2003
    Messages:
    29
    Likes Received:
    0
    Is it your knees?
    :)
     
  8. BIANCHI_EURO

    BIANCHI_EURO New Member

    Joined:
    May 30, 2004
    Messages:
    124
    Likes Received:
    0
    I have almost the same problem exept that, with me, the same subscribed sounds occur when I sit sowd on the saddle. Finally I located the trouble. It's the rear axle. When I put grease on the quick release mechanism it disappears for 3 trips and then it comes back.

    When I went to Campagnolo with my 3 year warranty on the new chorus hub they claimed they couldn't hear anything. Also they claimed they had been test riding for 5 days. Obviously the people at Campagnolo's (internationaly recognized) repair centre are deaf!!! When I cycle a short trip around here I get remarks about it from people in the street. Also my fellow cyclist complain about the anoying sound.

    About your problem.... When the mechanic does not clean the BB the proper way, metal pieces stay in the bracket house. This creates the sound you describe. Metal on metal sound, right? (just like with my axle). Take the BB out. Clean the house. Put BB back in with a lot of Shimano lok not (or whatever the name is). I mean their assembly past. This is known to be able to take out the cracking sound. (Look at the label on the bottle!).

    Regards, Frank.
     
  9. RC2

    RC2 New Member

    Joined:
    May 21, 2004
    Messages:
    905
    Likes Received:
    1
    If it's coming from the rear of the bike, it could be your hub. You can put your bike on a stand (or turn it upside down), put a little pressure on the brake or rear tire, and pedal to duplicate the sound...this may help isolate it. It can be hard to pinpoint that kind of sound due to the frame resonance that was mentioned, so you have to listen carefully...
     
  10. starship

    starship New Member

    Joined:
    Jun 16, 2004
    Messages:
    168
    Likes Received:
    0
    Thanks, to ALL OF YOU who have responded. One thing I have noticed, when back pedeling on the two big rear rings, the chain trries to ride off. Maybe under load on those big rings, the chain is poping off?
     
  11. RC2

    RC2 New Member

    Joined:
    May 21, 2004
    Messages:
    905
    Likes Received:
    1
    AH HAH! Go to parktools.com and look at the rear derailluer adjustment guideline. It will show you 1, how to adjust the limit screws, and 2, how to use the barrell adjuster to quickly tweak the jog pulley/derailluer alignment to your cogs.

    That must be it...simple. When you really get on your pedals and push hard, as you described, you are flexing your frame a bit and that's when slight derailluer miss-adjustments get exascerbated. :)
     
  12. starship

    starship New Member

    Joined:
    Jun 16, 2004
    Messages:
    168
    Likes Received:
    0
    Thanks! Will Do!
     
  13. carljohnson

    carljohnson New Member

    Joined:
    May 29, 2004
    Messages:
    16
    Likes Received:
    0
    Could be the bottom bracket, could be the cassette, could be the wheel hubs need rebuilding. You can eliminate the wheel hubs quickly. . . .just pick up the wheel and see if you can wobble it side to side. If so, start there. If not, move on to the cassette. Same thing - can you make it wobble with your hand? If so, that's your clunk. Depending on the style, it may need tightening, or something worse. If these are both tight, then go with the bottom bracket. (I just had the same problem and frankly, all three areas were in need of attention.)
     
Loading...
Loading...