Should i replace my crank or bottom bracket?
Different chain tension in different crank positions
byu/7R8NFR495 inbikewrench
by 7R8NFR495
Should i replace my crank or bottom bracket?
Different chain tension in different crank positions
byu/7R8NFR495 inbikewrench
by 7R8NFR495
9 Comments
Looks perfectly normal to me. I’ve never seen even chain tension on these set ups. There are always tighter and looser spots. Just make sure the “tight” spot isn’t too tight.
Only explanation is length of chain is changing. Bottom bracket is skew somehow, or chainring is oval/bent.
Not sure what else it could be.
I see this all the time on single speed bikes. Chainwheel is not perfectly round.
Chainrings are never perfectly round. At least I’ve never had a perfectly round one. Tension it at the tightest spot.
Chainring not centered on the crankarm.
Chainring and/or cog mount points are not centered.
In my case, the reason was cheap noname rear cog. Upgrading to a better quality one solved the issue.
You’re not supposed to use biopace chainrings on a single speed.
People pay crazy money for chainrings that are close to perfectly round. If you didn’t pay a lot of money for your cranks/chainring, it won’t be as round. But perfectly fine to ride for most people.
Loosen off your chainring and centre chaining on spider should make it way better, won’t be perfect but much better