Noise while freewheeling at speed?

mattsaw
mattsaw Posts: 907
edited January 2012 in The workshop
When I'm freewheeling at speed, either downhill or after pedalling hard on the flat I sometimes seem to get a vibrating scraping/rubbing noise, from I guess the back wheel, or sometimes it sounds like it's coming from the BB?

Any ideas on what this is and if I can fix it myself?
Bianchi C2C - Ritte Bosberg - Cervelo R3
Strava

Comments

  • nicklouse
    nicklouse Posts: 50,673
    got a loose idiot ring on the rear wheel?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mattsaw
    mattsaw Posts: 907
    It's also probably worth mentioning that the noise seems to vary between a dull grating that I can feel more than hear and then sometimes a screech like that you would hear with very squeaky brakes.
    Bianchi C2C - Ritte Bosberg - Cervelo R3
    Strava
  • mattsaw
    mattsaw Posts: 907
    nicklouse wrote:
    got a loose idiot ring on the rear wheel?

    The plastic thingy?
    Bianchi C2C - Ritte Bosberg - Cervelo R3
    Strava
  • The Rookie
    The Rookie Posts: 27,812
    Yes.....it spnds with the spokes but if it's loose can contact the cassette at first gear and grind/rub, have no place on any decent bike anyway.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • mattsaw
    mattsaw Posts: 907
    Yes.....it spnds with the spokes but if it's loose can contact the cassette at first gear and grind/rub, have no place on any decent bike anyway.

    Simon

    I took it off when I got the bike, so that can be ruled out :)
    Bianchi C2C - Ritte Bosberg - Cervelo R3
    Strava
  • bails87
    bails87 Posts: 12,998
    Mattsaw wrote:
    When I'm freewheeling at speed..... sometimes it sounds like it's coming from the BB?
    It can't be the BB if the cranks aren't moving, so you can rule that out.
    MTB/CX

    "As I said last time, it won't happen again."
  • nicklouse
    nicklouse Posts: 50,673
    Mattsaw wrote:
    Yes.....it spnds with the spokes but if it's loose can contact the cassette at first gear and grind/rub, have no place on any decent bike anyway.

    Simon

    I took it off when I got the bike, so that can be ruled out :)
    So that is that ruled out. So rubbing between freebody and the hub or brakes catching. Or even tyre catching frame?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mattsaw
    mattsaw Posts: 907
    I liberally sprayed some GT85 inside the back of the cassette last night, it seemed to solve the issues. :P
    Bianchi C2C - Ritte Bosberg - Cervelo R3
    Strava