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Concerning noise from my Bromptons wheel

Discussion in 'Folding Bikes' started by berylthebrompton, 8 Jul 2016.

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  1. berylthebrompton

    berylthebrompton Active Member

    Hello!



    I am getting this loud, "scratching" noise from my rear wheel. It happens when cycling in any gear, but also when free-wheeling. I can't get it to happen when the bike is off the ground/being worked on. It only happens when I am riding it. I have loosens the brake (incase it was rubbing) and it still happens. Makes me think its the weight of the rider and the sound is the spokes? If I am right I am concerned it may be something that needs to be looked at - as the wheels integrity may be compromised. Thoughts?

    If you agree it is the spokes, how do you go about resolving it?

    Cheers!

    James
     
  2. alicat

    alicat Veteran

    Location:
    Staffs
    It sounds like something is catching on the wheel to me, perhaps something that is nearer the wheel when your weight is on the bike.
     
  3. annedonnelly

    annedonnelly Girl from the North Country

    Anything inside the mudguard? Mine sometimes makes an alarming noise but it's the flap on the front mudguard being blown against the wheel.
     
  4. growingvegetables

    growingvegetables Veteran

    Location:
    Leeds
    +1 on thinking about the mudguard.
     
  5. berylthebrompton

    berylthebrompton Active Member

    Thanks for your replies.

    I got someone to sit on the bike and I checked - can't see anything that would be closer. Likewise, the rear triangle has everything attached to it, so nothing over closer to the wheel when weight is on it - it all moves together. The only thing that moves is the suspension block, but it doesn't sound like the normal "squeak" these can make.

    I checked the mudguard and can't see anything out of place that could be rubbing. Also checked inside incase something was stuck under it - nothing. Likewise, it wouldn't explain why the sound only happens when cycling - the mudguard isn't moving any close when the bike has weight on it, and the noise can't be reproduced by spinning the pedal with the wheel of the ground.
     
  6. Arellcat

    Arellcat Regular

    Location:
    Edinburgh
    It sounds like one of your spokes is much looser than the others. My B's back wheel broke a spoke after about 1000 miles; I replaced it as part of a full rebuild using a new rim and it's been fine for the subsequent 2500 miles. The Brompton wheel build quality is good but it can be better.
     
  7. shouldbeinbed

    shouldbeinbed Rollin' along Staff Member

    Location:
    Manchester way
    Have you played the spokes like a harp to feel for any difference in tension across them just to rule that out or in?

    I've never heard a loose spoke on any bike so loud it ticks to match the Brommy hub tic though. On or off the bike if that loose I'd expect to be able to find it pretty quickly, also I'd have expected those overloaded by such a rattly loose one to have failed already.

    It sounds like its a regular rhythmic tic as if something is hitting the same other thing each wheel turn, which would suggest something on, in or very close to the tyre on the bike given its greater give under bodyweight.
    V close would suggest catching on a spoke stay or the tail end of the mudguard.

    Noting your post above but a stationary sat on bike is different again to one sat on in motion so don't totally discount something catching.

    Could you get someone else to film you while riding; on a clear safe straight bit; as it's hard to see much in your clip that could help diagnose across the web.

    It's not clear if your tyres have a 3M reflective band around rhem, silly aa it my seem but could the end of that, if there, be standing proud and catching?
     
  8. Rohloff_Brompton_Rider

    Rohloff_Brompton_Rider Formerly just_fixed

    Sounds like drive side bearings to me. They are infamously sealed and dry out at the drop of a hat.
    Fiddly to do but easy enough and not overly complicated.
    There's plenty of YouTube videos.
     
  9. chris folder

    chris folder Active Member

    Hi:hello:it sounds like spoke area or mudguard should not be making that noise have you watched wheel in with bike lifted up see if anything rubbing check see if any spokes are loose on wheel and check under mudguard and rails to
     
    Last edited: 10 Jul 2016
  10. berylthebrompton

    berylthebrompton Active Member

    Thanks for all the replies.

    I checked for loose spokes and couldn't see any obvious ones - I slightly tightened one/two and it didn't make a difference. I then cleaned where the spokes join the hub, and behind the black plastic guard that sits between the sprockets and the hub - and this seems to have resolved it! Thinking something may have been caught between the guard/hub/spokes (which moved slightly under weight) and was rubbing and resonating through the spokes - making the sound.
     
  11. chris folder

    chris folder Active Member

    Hi great all ok now then:okay:
     
  12. berylthebrompton

    berylthebrompton Active Member

    The sound had returned! When you say drive side bearings, as in the ball bearings in the hub?
     
  13. SavageHoutkop

    SavageHoutkop Über Member

    When checking the mudguard, did you check the nut that keeps the flap on? That starts rubbing as the thing works loose, and just before it vanishes never to be seen again....
     
  14. Rohloff_Brompton_Rider

    Rohloff_Brompton_Rider Formerly just_fixed

    Yes, they're behind the sprockets.
     
  15. berylthebrompton

    berylthebrompton Active Member

    Okay. I think I agree with you - would explain a) why it happens when free wheeling, b) why it only happens when weight is applied to the axel and c) why it resonates through the spokes. Thing is, the bike is only 10 months old - has ridden less than 1000 miles. Surely the hub shouldn't need servicing already?
     
    dellzeqq likes this.