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I have an old two-seater recumbent trike with coaster brakes. One of the rear hubs rumbles terribly when the bike is coasting. When the brake is on, or when pedaling, it doesn't make a noise. I assume it's some bearing giving out, but it just had all the bearings replaced not long ago. Also, it's impossible to tighten up without making at least a slight grumble, so the wheel is slightly loose on the hub. What to do?

I don't know that I have the wherewithal to just replace the wheel... it's a bicycle hub with thick motorcycle spokes and rim and motorcycle tires. 20". I'd likely have to have a custom wheel built from scratch, plus find someone to cut small spokes.

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    There are several different schemes, but basically the coaster brake has two threaded shafts, one that tightens when you pedal, pulling together a clutch that drives the wheel, and one that tightens (as the other loosens) when you back-pedal, to pull together the brake. When you're coasting both the clutch and the brake are "open", but one or the other may be close to touching and hence make some noise. Or, if things are loose (which they should not be) it could simply be rattling inside. You should take it back to where you got the bearings replaced and have them fix it so it's not loose. Jul 29, 2014 at 0:28

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I had an exact same problem and I think I found a cause for it. As it's sold, an inner surface of a hub body on the drive side is smooth. As a clutch jams itself inside of the hub body while pedalling, the serrations on the clutch make grooves on this surface. Then, when You coast, those serrations and grooves spinning around each other make that awful noise. Hope I helped :).

Żelu

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  • But couldn't you find the sweet spot, where the clutch/driver isn't touching anything, by backpedaling a bit?
    – Robert
    Jul 18, 2018 at 22:55
  • @Żelu That's useful, but have you fixed your noisy hub? can you help the OP by offering a way to fix the problem?
    – Swifty
    Jul 19, 2018 at 18:30
  • @Robert Yes I could, but it's not really a solution...
    – Żelu
    Jul 20, 2018 at 8:55
  • Coming to @Swifty - I'm afraid there's nothing You can do about it. Perhaps filing those serrations on a hub body, but that'd be rather hard and probably not worth the cause.
    – Żelu
    Jul 20, 2018 at 8:55

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