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 07-30-11, 03:27 PM   #1
greese_monkey
Newbie
Thread Starter
 
Join Date: Jul 2011
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Rear derailleur arm is too high up

Hello,

I recently attempted to do some maintenance on my bicycle which resulted in an unexpected problem. I tried to remove the chain for cleaning by pulling on the rear
derailleur arm to reduce the tension on the chain and make it easier to remove. I eventually had to use a chain tool to remove the pin to get the chain off of the bike. After cleaning the chain and putting it back on the gears, I notice there was a lot of slack in the chain, and that the rear derailleur arm was very high up. It has to swing down (counter clockwise) about 150 degrees or so.

I am not sure how to adjust the position of the derailleur arm so that I can get the correct chain tension again. Does any one have any useful links or suggestions for me?

Thanks a lot
Attached Images
File Type: jpg forum post rear derailler.jpg (84.7 KB, 22 views)

Last edited by greese_monkey; 07-31-11 at 02:05 PM.
greese_monkey is offline   Reply With Quote
Old 07-30-11, 03:42 PM   #2
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 4,743
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 126 Post(s)
greese_monkey: A picture would help but from your description it sounds like you re-threaded the chain improperly. From the top of the front chainwheel it should run over the back of the cogs, over and in front of the upper jockey wheel and behind the lower one before heading to the bottom of the front chainwheel. Google "thread chain trough derailleur image" for some pictures. Here's one way to do it: http://www.livestrong.com/article/48...he-derailleur/
dsbrantjr is offline   Reply With Quote
Old 07-30-11, 04:15 PM   #3
mechBgon
Senior Member
 
mechBgon's Avatar
 
Join Date: Jul 2002
Bikes:
Posts: 6,957
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Based on the description, I'm guessing the arm got past its stop and is now in the part of the swing it would never ordinarily be able to reach. Some people just brute-force the arm back past the stop the other way, but if you want to be kind to your derailleur, you can also do it the "official" way. Park Tool has some helpful pictures here: http://www.parktool.com/blog/repair-...lleur-overhaul Scroll down to Shimano derailleur overhaul and look at photo #4 for the stop I'm talking about.
mechBgon is offline   Reply With Quote
Old 07-31-11, 02:16 PM   #4
greese_monkey
Newbie
Thread Starter
 
Join Date: Jul 2011
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Hi dsbrantjr,

thanks for you quick response. I have added a picture of the rear derailleur as an attachment on my original post. From reading through the webpage that you sent me, it sounds like that is the problem. I'll try that and let you know if it works.

Thanks a lot.
greese_monkey is offline   Reply With Quote
Old 07-31-11, 06:30 PM   #5
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Posts: 4,743
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 126 Post(s)
greese_monkey: Yes, it is definitely threaded incorrectly. The chain is going onto the cog from the wrong pulley in the wrong direction. Follow one of the online procedures and you should be OK. Keep in mind that the upper pulley does the shifting by guiding the chain onto the correct cog and the lower pulley takes up the slack in the chain. Best of luck.
dsbrantjr 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 04:50 AM.