Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-05-10, 05:15 PM   #1
Schwinn_Guy
Junior Member
Thread Starter
 
Schwinn_Guy's Avatar
 
Join Date: Nov 2009
Location: Vancouver, WA
Bikes: Gravity Avenue C 43 cm
Posts: 10
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Whistling/rubbing sound

So every time the rear wheel makes a rotation, a sound that strongly resembles brake rub emanates from what I think is the hub. I've triple checked that the brakes weren't rubbing, and removed the fender to rule out the possibility of fender rub on the tire.

Also, a strange knocking sound can be heard when the rear wheel is spun slowly, as if there were rocks tumbling around inside the hub.

Are these sounds related, and what can I do to eliminate them?
Schwinn_Guy is offline   Reply With Quote
Old 06-05-10, 11:41 PM   #2
oldbobcat
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Bikes: '79 Gios, '80 Masi, '06 Felt, early '60s Frejus
Posts: 2,926
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
The whistling sound might a rubber seal over the end of the bearing that rubs against the outside of the hub shell. If your hub has such seals, fold them back and insert a drop of light oil, such as Tri-flow or Boeshield T-9.

The knocking sounds like it might be a bad bearing, either in the main hub or the freewheel section. Does the wheel wobble sideways when you put pressure on a side of the rim? Does the knock appear only when coasting or under power? The sounds have different causes, but they both may warrant replacement of the hubs or wheels.
oldbobcat is offline   Reply With Quote
Old 06-06-10, 09:14 AM   #3
cny-bikeman 
Mechanic/Tourist
 
Join Date: Apr 2007
Location: Syracuse, NY
Bikes: 2008 Novara Randonee - love it. Would have more bikes if I had time to ride them all. Previous bikes: 1968 Motobecane Mirage, 1972 Moto Grand Jubilee (my fav), Jackson Rake 16, 1983 C'dale ST500.
Posts: 6,276
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 34 Post(s)
The knocking sound probably is bearings - does not necessarily indicate damage but most often indicates too little grease, or grease that has broken down. Overhaul the hub, lubricate the seals and then check for any remaining noises.
cny-bikeman is offline   Reply With Quote
Old 06-06-10, 10:38 AM   #4
bikinfool
I have senior moments...
 
bikinfool's Avatar
 
Join Date: Oct 2008
Location: Woodside, CA
Bikes: Many
Posts: 2,152
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Another possible cause of the rear wheel's noise could be a loose bit of metal from the rim manufacturing process, although that'd probably be more of a tick tick kind of sound. If in the hub I'd suspect the freehub if the hub bearings are already properly adjusted.
bikinfool is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:22 AM.