Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

MTB chain slipping off rings

Notices
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.

MTB chain slipping off rings

Old 02-04-08, 01:49 PM
  #1  
Tyrell
Senior Member
Thread Starter
 
Tyrell's Avatar
 
Join Date: Aug 2007
Location: Central TX
Posts: 580
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 4 Times in 1 Post
MTB chain slipping off rings

When I am in my middle chainring and get to cranking up a hill, the chain will sometimes fall off the inside and either wind up on my small chain ring or fall completely off and onto the BB. Doesn't happen all the time but it sucks when it does. I recently had a full drive train replacement and tune including chainrings, cassette, BB, and chain along with all cables. Will a simple front der. adjustment fix this? What else could be the cause?
Tyrell is offline  
Old 02-04-08, 02:28 PM
  #2  
Portis
Banned.
 
Join Date: Sep 2003
Location: Home alone
Posts: 6,020

Bikes: Trek 4300 X 2. Trek 1000, Trek 6000

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
http://www.youtube.com/watch?v=ngm6dr-1na0

Adjust the front der. first then go from there. There could still be other issues, like having the wrong lenght BB put in.
Portis is offline  
Old 02-05-08, 01:15 PM
  #3  
Tyrell
Senior Member
Thread Starter
 
Tyrell's Avatar
 
Join Date: Aug 2007
Location: Central TX
Posts: 580
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 4 Times in 1 Post
Didn't think about wrong length BB. I'll try the adjustment first and see where that leads me. Thanks!
Tyrell is offline  
Old 02-09-08, 02:45 AM
  #4  
z415
Senior Member
 
z415's Avatar
 
Join Date: Apr 2006
Location: Gainesville/Tampa, FL
Posts: 2,343

Bikes: Trek 1000, two mtbs and working on a fixie for commuting.

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Assuming you don't want to change parts, you can try to lose a link or two in the chain to increase tension or fine the screw in the backside of the RD that increases tension. I don't know the official name of the screw, but it is the one that you use when you want to bring your jockey wheels further from your cogs if they rub. If you remove a link, make sure you have enough links to cover the gear range you will use - some say enough to cover big cog/big ring, but I would think you wouldn't need that if you don't cross chain.

I had a similar problem when I went 1x9 on both my bikes, but after doing both those, I have no problems.
z415 is offline  
Old 02-09-08, 09:08 AM
  #5  
bmalmquist
Wrench User
 
Join Date: Nov 2007
Posts: 125
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by z415 View Post
Assuming you don't want to change parts, you can try to lose a link or two in the chain to increase tension or fine the screw in the backside of the RD that increases tension. I don't know the official name of the screw, but it is the one that you use when you want to bring your jockey wheels further from your cogs if they rub.
B screw.
bmalmquist is offline  
Old 02-09-08, 09:21 AM
  #6  
raleighrider75
2 B Frank w/U
 
raleighrider75's Avatar
 
Join Date: Jan 2008
Location: Ottawa,Ontario
Posts: 133

Bikes: 1963,1965,1968 and 1971 Raleigh Sports

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Maybe the new chainring doesn't line up properly with the cassette.Does it happen in high or low gears?Can you hear the chain rubbing on the front derailleur when it happens?
raleighrider75 is offline  
Old 02-09-08, 09:57 AM
  #7  
operator
cab horn
 
Join Date: Jun 2004
Location: Toronto
Posts: 28,354

Bikes: 1987 Bianchi Campione

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 36 Post(s)
Likes: 0
Liked 7 Times in 7 Posts
Originally Posted by z415 View Post
Assuming you don't want to change parts, you can try to lose a link or two in the chain to increase tension or fine the screw in the backside of the RD that increases tension. I don't know the official name of the screw, but it is the one that you use when you want to bring your jockey wheels further from your cogs if they rub. If you remove a link, make sure you have enough links to cover the gear range you will use - some say enough to cover big cog/big ring, but I would think you wouldn't need that if you don't cross chain.

I had a similar problem when I went 1x9 on both my bikes, but after doing both those, I have no problems.
The B-Screw is NOT for adjusting tension. This is NOT it's purpose. If youre tension is off, check the chain length. Other possibility is that the RD springs are worn out or you really are running a huge range of gears, say triple with mega-range back.

http://www.parktool.com/repair/readhowto.asp?id=26
operator is offline  
Old 02-09-08, 11:14 AM
  #8  
mark9950
Senior Member
 
Join Date: Jan 2008
Posts: 439
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
simple solution,remove the front deraillure ,you dont need it.
mark9950 is offline  
Old 02-10-08, 08:21 AM
  #9  
bmalmquist
Wrench User
 
Join Date: Nov 2007
Posts: 125
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by operator View Post
The B-Screw is NOT for adjusting tension. This is NOT it's purpose. If youre tension is off, check the chain length. Other possibility is that the RD springs are worn out or you really are running a huge range of gears, say triple with mega-range back.

http://www.parktool.com/repair/readhowto.asp?id=26
Indeed. Didn't mean to mislead. I was just naming the screw. The B screw is to space the jockey wheel away from the cassette so that there's no rubbing/interference.
bmalmquist is offline  
Old 02-11-08, 08:07 AM
  #10  
Tyrell
Senior Member
Thread Starter
 
Tyrell's Avatar
 
Join Date: Aug 2007
Location: Central TX
Posts: 580
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 4 Times in 1 Post
I don't remember hearing the chain rub anything when it happens. I'll check the chain length too, front der. adjustment is good. Haven't had alot of time to do much wrenching or riding these days as work has been monopolizing the daylight hours. Thanks again, folks!
Tyrell is offline  
Old 02-13-08, 11:15 AM
  #11  
JSellers
Senior Member
 
Join Date: Feb 2008
Location: Mississippi
Posts: 79

Bikes: Gary Fisher Hoo Koo E Koo

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Are you using grip shift?
JSellers is offline  
Old 02-18-08, 10:41 AM
  #12  
Tyrell
Senior Member
Thread Starter
 
Tyrell's Avatar
 
Join Date: Aug 2007
Location: Central TX
Posts: 580
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Likes: 0
Liked 4 Times in 1 Post
No grip shift - Shimano Rapid fire. Still haven't had a chance to give the bike a look...been spending lots of time on the road as of late. I'll report back when I get it sorted out.
Tyrell is offline  

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.