Originally Posted by
hythamfekry
I already adjusted index and limits as well as , chain is not rubbing or bouncing on sprocket ...
when rotating crank by hand on high RPM , i sense like a vibration , sound is more like something is drivetrain i wiggling/vibrating , rather that the sound of friction/rub when indexing is not adjusted ..
that's only on big ring / smallest sprocket "12 teeth" , it's less on the 2nd smallest sprocket "13 teeth" and not noticed on larger sprockets
What you are feeling is the chain rotating around the small cog. That buzz I think you are referring to gets quieter as you shift up as you described.