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 04-15-12, 11:54 AM   #1
Myosmith
Lover of Old Chrome Moly
Thread Starter
 
Myosmith's Avatar
 
Join Date: May 2011
Location: NW Minnesota
Bikes:
Posts: 2,548
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Mystery drivetrain squeak

I've got a hard to locate squeak in the drivetrain of my touring bike. When pedaling under load there is a constant, rapid succession of tiny squeaks. I've also noticed that there seems to be a slight drag. The noise is such that it is very hard to pinpoint while riding. Sounds like a half dozen hamsters running on metal exercise wheels simultaneously, but very soft. Here is what I have found out so far:
  • Noise only occurs under load such as accelerating, uphill or into the wind
  • The noise occurs consistently and constantly under those conditions
  • The noise is only present when pedaling
  • The brakes are properly adjusted and have adequate clearance
  • Both wheels have been serviced and the hubs relubed this spring, no play and they spin freely, no lose spokes and tension fairly equal by ping
  • Cassette and chain have been removed and cleaned, neither is badly worn or damaged
  • No visible damage to chainrings and cranks are tight, noise is a rapid series of fine squeaks rather than the intermittent creak associated with a loose crank
  • With the chain off the crank can be spun freely with no grinding or vibration
  • Pedals are brand new and spin freely by hand without noise, still oozing tiny amount of lubricant at the spindle
  • Bike was in minor endo at low speed earlier this spring but passed inspection by the LBS, chrome moly 1989 Trek 700 frame, has been on the stand and inspected by me several times since and can't find any problems, dropouts are straight and aligned, measurements all equal from one side to the other and lines straight by plumb bob and straight edge
The only thing I haven't done is replace the BB which is a Shimano UN54 that was installed last spring and has about 2200 miles on it. The bike was ridden a lot during the winter including a number of days below zero F and on salted roads in MN but bike was kept clean and well lubed. I have been unable to replicate the noise with the bike on the workstand.

Any other thoughts? Am I missing something?

Last edited by Myosmith; 04-15-12 at 12:00 PM.
Myosmith is offline   Reply With Quote
Old 04-15-12, 12:05 PM   #2
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,892
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 232 Post(s)
Even harder to guess 2000 miles away.. ride and ignore..
fietsbob is online now   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 12:58 PM.