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.

Chain skip

Old 02-02-19, 07:45 AM
Thread Starter
Join Date: Sep 2012
Location: Nanaimo, BC, Canada
Posts: 25

Bikes: Velo Orange Pass Hunter Disc, Marin San Quentin, Rocky Mountain Blizzard

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Chain skip

I bought a new bike frame with vertical dropouts and put my Alfine 11 on the rear. For chain tension I use a Surly Singleator and am experiencing chain skipping over the tensioner, which carries over to the cog and skips a tooth. This only happens with the singleator in push down mode and when I put more power through the pedals. In push up mode it's fine, probably because there is more chain wrap. I did put a new chain on the new bike and a new jockey wheel on the singleator, but haven't changed the cog or chainring there. The singleator was on my MTB in push down mode and never had this problem and I crank harder with a smaller chainring. I am okay with the tensioner in push up mode but like the look of the chain line in push down mode better. I suspect it's because the chainline is out by about 1mm between the chainring and the cog, but I don't think it's perfect on the MTB either.
TwinOaks is offline  
Old 02-02-19, 10:54 AM
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,350 Times in 857 Posts
I have no issues with 2 pulley spring loaded chain tension ers... essentially a short cage rear mech aligned to sit over the single cog,

I fit Tacx Pulleys on them.. so no real rolling Resistance.. to chain passing over them...


Last edited by fietsbob; 02-02-19 at 11:00 AM.
fietsbob is offline  
Old 02-02-19, 04:05 PM
Senior Member
Andrew R Stewart's Avatar
Join Date: Feb 2012
Location: Rochester, NY
Posts: 17,695

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4035 Post(s)
Liked 3,461 Times in 2,098 Posts
1mm of chain line offness should not matter to a "single" chain/cog/ring system.. I also question that the tensioner pulley has anything to do with the skip too. Being spring loaded the pulley only has the spring's force acting on the chain. Now the amount of chain wrap around the cog, from the pulley pulling up or pushing down, very much can affect the chance of skip. I would look at the cog, compare to a new one for tooth profile/shape. I suspect you'll see tooth wear. I also suspect a new cog will clear things up. Ring teeth do also wear but with so many points of engagement, compared to the cog, it takes more wear to get ring skip. Andy
Andrew R Stewart is offline  
Old 02-02-19, 04:40 PM
Advanced Slacker
Kapusta's Avatar
Join Date: Feb 2017
Posts: 6,103

Bikes: Soma Fog Cutter, Surly Wednesday, Canfielld Tilt

Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 2707 Post(s)
Liked 2,462 Times in 1,391 Posts
How old is the cog?
Kapusta is offline  
Related Topics
Thread Starter
Last Post
Singlespeed & Fixed Gear
10-20-21 06:09 PM
Bicycle Mechanics
04-14-21 11:31 AM
Bicycle Mechanics
07-05-15 05:11 PM
Bicycle Mechanics
03-19-15 05:54 PM

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

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.