Slight skip when peddling

[mdvineng]

Read Post #8

If it skips every other revolution in the same crank position, the culprit could be a chain connector/master link. They have a habit of stretching and then the master link skips off the rear sprocket teeth. Check by measuring across the section with the master link included using a chain wear indicating tool. Compare with other measured chain sections.

 

[jaguargod2000]

I have the same problem on the none drive side, single speed 1950's east german path racer... I've checked cranks bb, cotter pins, pedals (changed for known good 'uns), but didn't consider stiff chain link/s and or worn chain/sprocket teeth. will check and report back..

 

[peetee]

you said when the pedal reaches the top?
Which pedal?
I have a suspicion that one crank has a worn taper allowing it to move relative to the other.

 

[jaguargod2000]

left side (non drive). ive checked: bottom bracket, cotter pins, crank arms, pedal threads, pedal bearings, chain/sprocket/chainring wear, chain link seizure etc, the only thing i can think off is maybe a weird 'freewheel mech problem????

 

[jaguargod2000]

when you say worn taper, do you mean the taper of the bottom bracket spindle???

 

[peetee]

when you say worn taper, do you mean the taper of the bottom bracket spindle???

That interface, yes, but it is far more likely the ‘square hole’ in the crank isn’t square any more.

 

[jaguargod2000]

Solved! It was worn cotter pin shamfer and thread. Only a 1/3rd of part of the thread was missing, but enough to work loose over time. Had hell of a time sourcing a similar item, but eventually found a 'Brompton' cotter with same spec!

 

[averagebiker]

Good news, thanks for posting details of the issue and it's cure