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

Drive Train Skipping Under Load

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.

Drive Train Skipping Under Load

Old 10-18-19, 01:43 PM
  #1  
SuperK
Newbie
Thread Starter
 
Join Date: Oct 2019
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Drive Train Skipping Under Load

I am at a loss here and any help would be much appreciated! I am trying to work on a ~2002 9 speed Ultegra 6500. I have replaced all cables, cable housing, and barrel adjusters. I have replaced the entire drive train (chain, chain rings, cassette, jockey wheels, and bottom bracket), re-aligned rear derailleur hanger, reset limit screws, and seem to have cable tension where it should be. On the surface every thing seems to work smooth if. I ease into things everything is really smooth the system can take any load. However if I start pushing the torque the chain starts to skip on the cassette. Is there anything else I should take a look at?

Thanks!

( !?!)
SuperK is offline  
Old 10-18-19, 03:00 PM
  #2  
dsaul
Senior Member
 
Join Date: Jan 2013
Posts: 1,191
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 299 Post(s)
Liked 72 Times in 56 Posts
Sounds like a freehub problem. What hub is on the rear wheel?
dsaul is offline  
Old 10-18-19, 06:12 PM
  #3  
nomadmax 
Senior Member
 
Join Date: Jun 2018
Location: SW Ohio
Posts: 1,103
Mentioned: 80 Post(s)
Tagged: 0 Thread(s)
Quoted: 471 Post(s)
Liked 352 Times in 198 Posts
Does it slip on one cog or all of them?

Usually:

One cog = a cassette/cog problem

All cogs = a chain problem

Slowly pedal the crank backwards with your hand. Look at the chain near the jockey wheels and look for a stiff link. There are other causes including a bent RD hanger but a stiff link is usually to blame.

Last edited by nomadmax; 10-19-19 at 04:31 AM.
nomadmax is offline  
Old 10-18-19, 06:19 PM
  #4  
Soody
Senior Member
 
Soody's Avatar
 
Join Date: Mar 2015
Location: New Zealand
Posts: 456

Bikes: Gunnar crosshairs, F Moser, Ken Evans, Pete Tansley, Rocky Mountain Summit, Cinelli mtb

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Likes: 0
Liked 19 Times in 16 Posts
It could also be skipping because of your shifting, if your indexing is not set correctly, your hanger is bent, or if there is some friction or something not seated correctly in the line acting like a clutch
Soody is offline  
Old 10-18-19, 07:28 PM
  #5  
Bigbus
Senior Member
 
Bigbus's Avatar
 
Join Date: Mar 2018
Location: Central West Coast
Posts: 375

Bikes: In Flux

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
Liked 32 Times in 23 Posts
It appears that you've already thrown everything at it but the kitchen sink. My first guess is a sticky chain link. That'll cause precisely what you're experiencing if all else is in alignment. But you say you already replaced that too so I'll just scratch my head a little longer here. Oh, wait a minute, you don't mention swapping out the frame...
Bigbus is offline  
Old 10-18-19, 07:32 PM
  #6  
rccardr 
aka: Dr. Cannondale
 
rccardr's Avatar
 
Join Date: Jul 2009
Posts: 5,550

Bikes: Lots. Just...lots.

Mentioned: 163 Post(s)
Tagged: 0 Thread(s)
Quoted: 1107 Post(s)
Liked 85 Times in 63 Posts
I'd vote for a sticking link, or possibly cassette spacers too narrow Sure that's a 9 speed cassette? Sure it's not an 8 speed chain?
__________________
Hard at work in the Secret Underground Laboratory...
rccardr is offline  
Old 10-19-19, 09:34 AM
  #7  
frankenmike 
mechanically sound
 
frankenmike's Avatar
 
Join Date: Jan 2007
Location: Dover, NH
Posts: 1,500

Bikes: Indy Fab steel deluxe, Aventon cordoba, S-works stumpy fsr, Masi vincere, 92 Hardrock commuter, Dahon mu uno, Outcast 29

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Liked 14 Times in 11 Posts
RD adjustment, broken free hub, or stiff chain links.
__________________
frankenmike is offline  
Old 10-20-19, 01:34 PM
  #8  
SuperK
Newbie
Thread Starter
 
Join Date: Oct 2019
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks All! I will take a closer look...
SuperK is offline  
Old 10-21-19, 02:11 PM
  #9  
SuperK
Newbie
Thread Starter
 
Join Date: Oct 2019
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by dsaul View Post
Sounds like a freehub problem. What hub is on the rear wheel?
Don't want to celebrate to early, but going to take a look and hopefully rebuild this week (if not replace). Makes total sense and one of the few things I didn't check! Thanks so much!!! Will report back...
SuperK 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.