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 12-25-07, 06:46 AM   #1
EMT
Senior Member
Thread Starter
 
EMT's Avatar
 
Join Date: Jun 2007
Location: Tokyo
Bikes:
Posts: 392
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Chain rubbing front derailleur cage when backpedaling

Hi--I hope this topic hasn't been covered before endlessly---the search function is not working properly, or else I am failing to use it properly.

As the title of the thread says my chain rubs the front derailleur cage when I backspin the pedals, but not when I actually pedal. Why is this? Is there something I can do about it (besides not backspin in high gears)? Thanks!
EMT is offline   Reply With Quote
Old 12-25-07, 07:21 AM   #2
Stacey
Non Tribuo Anus Rodentum and off to the next adventure (RIP)
 
Stacey's Avatar
 
Join Date: Dec 2002
Bikes:
Posts: 9,161
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Clean & lube chain and adjust the derailer.
__________________
Stacey is offline   Reply With Quote
Old 12-25-07, 09:12 AM   #3
EMT
Senior Member
Thread Starter
 
EMT's Avatar
 
Join Date: Jun 2007
Location: Tokyo
Bikes:
Posts: 392
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Fair enough. Thanks.
EMT is offline   Reply With Quote
Old 12-25-07, 09:15 AM   #4
HillRider 
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Posts: 28,920
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 96 Post(s)
It's not a problem if it doesn't rub while pedalling forward. If it bothers you a lot you could adjust the fd's high limit screw or tighten the shift cable slightly as long as that doesn't mess up the shifting.
HillRider is offline   Reply With Quote
Old 12-25-07, 09:32 AM   #5
San Rensho 
Senior Member
 
Join Date: Oct 2005
Bikes:
Posts: 5,548
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
If it only happens when using small/small combinations, then its likely the chain hitting the pin that connects both side rails of the front der. Check to see that the chain legnth is correct, too long a chain will give too much slack which is only evident when you backpedal.

But be careful if you need to shoten the chain, you have to set the chain legnth to make sure you have enough chain for the big/big combo, if its too short for that combo, you will rip off the rear der.
__________________
Il faut de l'audace, encore de l'audace, toujours de l'audace

1980 3Rensho-- 1975 Raleigh Sprite 3spd
1990s Raleigh M20 MTB--2007 Windsor Hour (track)
1988 Ducati 750 F1
San Rensho is offline   Reply With Quote
Old 12-25-07, 09:51 AM   #6
SoonerBent
<><
 
SoonerBent's Avatar
 
Join Date: Oct 2004
Location: Oklahoma City
Bikes: RANS Tailwind
Posts: 768
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Also, when you backpedal there's no tension on the chain as it passes through the FD cage. That lets the chain flop around more than when pedaling.
SoonerBent 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 08:16 AM.