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

Gears jumping on fifth & sixth cogs

Search
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.

Gears jumping on fifth & sixth cogs

Thread Tools
 
Search this Thread
 
Old 05-21-09, 05:57 PM
  #1  
Muscle bike design spec
Thread Starter
 
robtown's Avatar
 
Join Date: Oct 2004
Location: Sterling VA
Posts: 3,688

Bikes: 70 Atala Record Proffesional, 00 Lemond, 08 Kestrel Evoke, 96 Colnago Master Olympic, 01 Colnago Ovalmaster, 76 Raleigh Gran Sport, 03 Fuji World, 86 Paramount, 90 Miyata CF, 09 Ritchey Breakaway CX, Bianchi Trofeo, 12 OutRiderUSA HyperLite

Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Gears jumping on fifth & sixth cogs

I was riding my PX10 yesterday and it the chain was jumping only on cogs 5 & 6 (of 6). I believe I've used the freewheel before w/o problems. I'll be checking the chain but - can a stuck link only bother the higher gears? What else should I check? It's friction shifting BTW.

Thanks
__________________
Korval is Ships
See my Hyperlite 411 it's the photo model on OutRiderUSA web page
robtown is offline  
Old 05-21-09, 06:06 PM
  #2  
My bike's better than me!
 
neil0502's Avatar
 
Join Date: Feb 2005
Location: Northern Colorado
Posts: 2,041

Bikes: (2) Moots Vamoots, (1) Cannondale T2000 tourer, (1) Diamondback Response Comp mtb

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Cables/housings -- clean/replace?

Do you have a cable guide, under your BB shell? If so, clean it up well with WD/whatever, and make sure you don't have any friction, there.

Sheldon? Anything else??

https://www.sheldonbrown.com/autoshift.html
neil0502 is offline  
Old 05-21-09, 07:29 PM
  #3  
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 7 Times in 6 Posts
Have you measured the chain? Any 24 pin interval should measure 12 inches. If you let it stretch to 12 1/8th you may have ruined the freewheel, and a new chain will slip on some cogs, usually the smaller ones.

If you suspect a tight link, use your fingers to pivot each link around each pin until you find it. Carefully loosen the tight link slightly with a tool.

Al
Al1943 is offline  
Old 05-21-09, 08:32 PM
  #4  
Muscle bike design spec
Thread Starter
 
robtown's Avatar
 
Join Date: Oct 2004
Location: Sterling VA
Posts: 3,688

Bikes: 70 Atala Record Proffesional, 00 Lemond, 08 Kestrel Evoke, 96 Colnago Master Olympic, 01 Colnago Ovalmaster, 76 Raleigh Gran Sport, 03 Fuji World, 86 Paramount, 90 Miyata CF, 09 Ritchey Breakaway CX, Bianchi Trofeo, 12 OutRiderUSA HyperLite

Mentioned: 1 Post(s)
Tagged: 1 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
Originally Posted by neil0502
Cables/housings -- clean/replace?

Do you have a cable guide, under your BB shell? If so, clean it up well with WD/whatever, and make sure you don't have any friction, there.

Sheldon? Anything else??

https://www.sheldonbrown.com/autoshift.html
Bike's clean and the chain and cables are new. I did put a different wheelset/freewheel on.

Originally Posted by Al1943
Have you measured the chain? Any 24 pin interval should measure 12 inches. If you let it stretch to 12 1/8th you may have ruined the freewheel, and a new chain will slip on some cogs, usually the smaller ones.

If you suspect a tight link, use your fingers to pivot each link around each pin until you find it. Carefully loosen the tight link slightly with a tool.

Chain is new. I was polishing parts for my Soma reubild tonight, but I'll throw the PX10 on the stand to check the chain links. It'd just be odd it runs smooth in the other gears.

Al
__________________
Korval is Ships
See my Hyperlite 411 it's the photo model on OutRiderUSA web page
robtown is offline  
Old 05-21-09, 08:40 PM
  #5  
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,786

Bikes: Several, mostly not name brands.

Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3588 Post(s)
Liked 3,400 Times in 1,934 Posts
A stiff link will complain more on the smaller cogs since it needs to bend more as it travels over them. Watch the chain closely as it passes through the derailleur and over the cogs -- you should be able to isolate the problem link(s). Gasp the chain firmly and flex the problem link(s) sideways a few time to loosen them up. If that doesn't fix it, you may need to use a link spreader such as is found on the old Cyclo chain tools.
JohnDThompson is offline  
Old 05-21-09, 08:43 PM
  #6  
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 24,786

Bikes: Several, mostly not name brands.

Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3588 Post(s)
Liked 3,400 Times in 1,934 Posts
Originally Posted by robtown
Bike's clean and the chain and cables are new. I did put a different wheelset/freewheel on.
This may be your problem. A new chain on a worn freewheel will often cause this problem. You need to use a new freewheel with your new chain.
JohnDThompson 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.