My bike is making a weird squelching sound from the back wheel. Any idea what it might be? I made a video of the sound, it's at this link: https://drive.google.com/file/d/1zt_DAa2avX9bhJ4E-moLFJ69TSYnb2uC/view?usp=sharing

Summarising comments:

  • the noise is in the rear wheel
  • frequency is linked to wheel/road speed and not chain speed because noise continues when coasting,
  • noise does not change when the rear coaster brake is applied
  • noise only appears when bike is loaded, not walked
  • there is nothing rubbing on the tyre
  • 2
    It's obviously tied to wheel rotation. Could be something as simple as a twig caught in the spokes and hitting the frame. Could be something with the brakes. Could be a bad bearing. May 8, 2020 at 21:53
  • 1
    It appears that you just have "coaster brakes" (backpedal brakes) so they're not the problem unless the hub is hosed. I'd suggest that you walk the bike while examining the rear wheel closely, looking for anything rubbing. May 8, 2020 at 21:56
  • 1
    Does the sound change if you briefly apply, then release the brakes? May 8, 2020 at 22:52
  • 1
    Just today I was out on my cruiser and heard a similar sound. On my wheel is was a couple of untensioned spokes. does this sound happen when you walk the bike? Or only when you sit on it and ride?
    – bradly
    May 9, 2020 at 0:14
  • 1
    Yeah, it could be the tire "scrunching" because pressure is low and the tire isn't properly centered on the rim. Vaguely possible that it's loose/broken spokes, but it doesn't sound like that. May 9, 2020 at 12:41

2 Answers 2


It sounds from the audio like the tyre is rubbing somewhere. The sound is certainly related to the wheel because the frequency speeds up and slows down with bike speed, not pedalling.

You say the tyre isn't rubbing, but the sound doesn't happen when bike is unloaded, so perhaps when it is fully loaded, the frame is flexing enough to cause a rub - is there any point like behind the downtube or close to a mudguard or chain stay where the tyre is close to something? Then when it is loaded up it is able to rub.

It's also making the noise once per revolution of something (the wheel) so something is out of balance. Maybe the wheel isn't true, radially or laterally, or the tyre is bulging at one point on its circumference.


You have a bulging tyre segment and it making the sound when the area scissors on the road.

Look at the shape of the tyre surface.

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