Took out the motor to pass new gear cable & housing.
I thought I’d clean the front cog (weirdly had accumulated dirt on every other teeth), now it’s jumping on the bottom side !
Like the chain is sucked in.
What am I doing wrong ? Is the cog due for a change ?
Thanks
Front cog : Why is this happening ?
byu/Gullible_Rate_4012 inbikewrench
by Gullible_Rate_4012
8 Comments
Check for some marks or in the manual if the cog is not installed backwards. I assume that shouldn’t be possible because of the grooves layout on the spindle, but I don’t remember now how they look by memory.
I believe that’s a sign of a worn chainring
Looks like a worn cog (chainring).
But I would suggest that you check your chain and casset. Usually not only one worn part on a chain drive!
Chain links have grit in them causing the pull as they don’t slide cleanly. When was chain last lubed?
Worn chainring. Is that a new chain?
Narrow-wide chain … reposition it one link forward/backward on the chainring.
[https://www.bikeradar.com/advice/buyers-guides/narrow-wide-chainring](https://www.bikeradar.com/advice/buyers-guides/narrow-wide-chainring)
First clean your whole drivetrain: chain, cassette and the cog. If the problem persists then most probably it is a worn cog. And in this case, most probably you need also new chain and cassette.
Lack of oil. Or using hair removal wax. Too sticky and covered in pubic hair.