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 05-03-10, 01:37 PM   #1
Tony5mlc
Newbie
Thread Starter
 
Join Date: May 2010
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
clunking from front mech

Hi all,

I'm after some help if anyone can...... me and my son are new to road biking, and my sons bike has developed a problem....

I bought his bike second hand, it has worked fine for a few months but has now developed a knocking / clunking noise that seems to be coming from the front mech...... it's not the sound that it makes when it is trying to change gears, it sounds much worse.....
It happens in all gears but only at higher speeds when the bike is under more stress..... he is running shimnano 105 front mech with sora rear...
Tony5mlc is offline   Reply With Quote
Old 05-03-10, 01:46 PM   #2
JiveTurkey
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
Posts: 2,407
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The front deraillaur only touches the chain when shifting (ideally), so if the noise occurs while not shifting and there's no rubbing (such as when in the middle of the cassette/freewheel in the rear), I don't think it's the FD.

My first thought is it could be the pedals. Grab one at at a time and try to move it around against the spindle. Do you feel any play in either?

It might also be the bottom bracket. Grab the end of one of the crank arms and push and pull it toward and away from the frame. Feel any play?
JiveTurkey is offline   Reply With Quote
Old 05-03-10, 02:04 PM   #3
Tony5mlc
Newbie
Thread Starter
 
Join Date: May 2010
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
it's defo not from the deraillaur like you say... and doesn't sound like the chain rubbing at all....

I did a quick check of the pedals too as this was my first idea, couldn't see any play but will double check it 2moro when it is light, and your bottom bracket idea......

If it is the bottom bracket like you mention, can that just be tightened up or will it need replacing.... many thanks for your help buddy, greatly appreciated
Tony5mlc is offline   Reply With Quote
Old 05-03-10, 03:07 PM   #4
JiveTurkey
Low car diet
 
JiveTurkey's Avatar
 
Join Date: Aug 2007
Location: Corvallis, OR, USA
Bikes: 2006 Windsor Dover w/105, 2007 GT Avalanche w/XT, 1995 Trek 820 setup for touring, 201? Yeah single-speed folder, 199? Huffy tandem.
Posts: 2,407
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Depends on the bottom bracket type.

If it is a traditional spindle and cup bottom bracket, then the cups may be able to just be adjusted.

Newer cartridge or outboard BBs should just be replaced.
JiveTurkey is offline   Reply With Quote
Old 05-04-10, 10:42 AM   #5
Tony5mlc
Newbie
Thread Starter
 
Join Date: May 2010
Bikes:
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks for your help jive turkey, you were correct with the bottom bracket being worn, there was slight play in there and this was confirmed by the local bike shop who is now replacing the bracket.....

Many thanks for your advice
Tony5mlc 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 01:56 AM.