New: Take part in the January 2020 BikeRide Giveaway for a HEDKAYSE | ONE bike helmet

Welcome guest! Register or sign in to participate in the cycling discussions.


Loud intermittent metallic clacking from rear hub
#1
I have an Electra Townie 21 with less than 600 miles on it. I clean and lub the chain often. The hub is a Shimano MegaRange Super low 14-34T. About 50 miles ago, an intermittent metallic clacking started coming from the rear hub. Like metal hammering on metal. It would continue during freewheeling or back peddling and the rate increased with speed. It has become progressively louder but still intermittent. A tack-tackity tack-tack repeated. But, it may almost go away on a 5 mile ride or return with a vengeance or it may be there the whole ride, staying loud or getting louder or quieter. I recorded the sound holding a small digital recorder toward the hub. It sounds like a metal striking metal.

The local shop service guy put it on a stand but there was no noise. After a ride, he told me his bike did the same thing and dismissed my concerns. I wondered if it could be a bearing going bad, with the race getting stuck and releasing intermittently. But he told me the bike isn't old enough? My confidence in his assessment is sorely lacking. It is definitely not normal.

When I click on "Add an Attachment" to upload a short m3 of the noise, this window is kicked back to the top but offers no way to add an attachment. It says I'm 'currently using N/A of your allocated attachment usage (Unlimited)'. I have no previous attachments. Does N/A mean not allowed?

A short mp3 of the sound might allow someone to diagnose the problem.

Thanks,
Max
  Reply
#2
Well one of my old bikes does that, but it has a freewheel, not a cassette & freehub. I don't think the wheel bearings could make that kind of noise, there would be more grinding & popping. Maybe the freehub.
Your LBS should have tried harder.
Are you mechanically inclined? You only need a few tools to be able to take things apart back there. Oh, & some grease too.
  Reply
#3
If it only happens when you're coasting, I'm thinking it's a bad bearing/pawl in the freewheel/freehub. If you have a 7 speed "mega-range" gear cluster, I'm pretty sure that's a freewheel, not a cassette. So, I'm voting that you have a bad freewheel. If so, could be fine (but annoying) for years. Or it could suddenly fail and you won't be able to pedal forward at any time.

It could also be a problem in the rear hub bearings. You would expect this to show up when you're pedaling as well as freewheeling, but sometimes these things are tricky. This is a more immediate issue since if it is a bad bearing, it could be destroying your hub meaning you will need to get a whole new rear wheel.

It's tough for any mechanic to diagnose something when the bike refuses to do what it's doing when you bring it in. You may want to pay them to rebuild the rear hub to rule out it being bad hub bearings. There shouldn't be any doubt once they can inspect it visually inside.

Last thing you could try. Lay the bike on it's side, spin the rear wheel, find the border on the rear gear cluster between where the center part rotates and the outer part stays still. Drip some thick oil like car oil in that crack and let it work in for a few minutes. If that changes the sound you hear next time it does it while riding, it probably means the problem is the freewheel.
  Reply
#4
(06-05-2012, 12:34 AM)DaveM Wrote:  If it only happens when you're coasting, I'm thinking it's a bad bearing/pawl in the freewheel/freehub. If you have a 7 speed "mega-range" gear cluster, I'm pretty sure that's a freewheel, not a cassette. So, I'm voting that you have a bad freewheel. If so, could be fine (but annoying) for years. Or it could suddenly fail and you won't be able to pedal forward at any time.

It could also be a problem in the rear hub bearings. You would expect this to show up when you're pedaling as well as freewheeling, but sometimes these things are tricky. This is a more immediate issue since if it is a bad bearing, it could be destroying your hub meaning you will need to get a whole new rear wheel.

It's tough for any mechanic to diagnose something when the bike refuses to do what it's doing when you bring it in. You may want to pay them to rebuild the rear hub to rule out it being bad hub bearings. There shouldn't be any doubt once they can inspect it visually inside.

Last thing you could try. Lay the bike on it's side, spin the rear wheel, find the border on the rear gear cluster between where the center part rotates and the outer part stays still. Drip some thick oil like car oil in that crack and let it work in for a few minutes. If that changes the sound you hear next time it does it while riding, it probably means the problem is the freewheel.

Thanks for the response.

Sorry, I wasn't clear. The noise is there, peddling or coasting. The bike shop repair guy rode the bike and heard the same thing, then dismissed my concerns. It may be my imagination, but it seems the noise is 'felt' through the frame.

I'll try the oil suggestion. And I might take it back where I bought it for a second opinion. The local shop is a couple of miles the Electra dealer 20.
  Reply
#5
sounds like a repair or replace under warrenty to me.
  Reply
#6
Did you buy it new from an authorized Electra dealer?
When did you buy it?
  Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Shimano FH-1055 Rear hub assembly flor1n 0 10,100 10-10-2017, 11:08 AM
Last Post: flor1n
  Rear hub spins to a near stop, then reverses to a stop Gogogordy 2 3,808 07-23-2017, 07:30 PM
Last Post: Gogogordy
  Shimano Deore rear hub and Shimano CS-HG20-7 Sprocket Lighttower 4 7,827 12-04-2015, 12:39 AM
Last Post: Lighttower
  Loud clicking noise when peddling uphill in larger gears khfrekek 3 5,692 07-09-2015, 08:42 PM
Last Post: DaveM
  Shimano wh-6600 rear hub overhaul stdu007 3 12,074 01-26-2015, 06:21 PM
Last Post: eamil
  Help with rear hub pls. igoris.bo 6 6,328 06-09-2014, 06:07 PM
Last Post: nfmisso
  Intermittent trouble with rear gear shifting imaytag 2 4,507 05-18-2014, 06:41 PM
Last Post: imaytag
  Rear wheel hub service problem British Eagle 3 6,832 11-24-2013, 12:58 PM
Last Post: British Eagle
  Clacking noise post-tire change jmbarry 3 4,364 11-20-2013, 08:25 PM
Last Post: jmbarry
  Gipiemme Grecal Rear Hub wesf0711 1 2,878 07-08-2013, 02:55 AM
Last Post: nfmisso

Forum Jump: