Hi,
I wonder if anybody else has experienced this: while pedaling the crank arm jumps forward, maybe once or like yesterday four times one after another. Quite nasty experience though happening rarely, all suddenly but makes me worried - what’s wrong? This last occasion happened while riding slightly downward sloping way thus no much force on pedaling required. Unfortunately didn’t make mental note on which gear I was riding, likely not on the light gear anyway.
Easy or difficult case to solve and repair? Thanks.
seems that this is a drive issue; your dealer should exchange it.
As far as I know they’ll be sent back to the factory for repairing.
Also should your dealer be able to mount/unmount the beltwheels of the drives if necessary.
There is a special “hook nut” and an electric (or pneumatic) impact wrench required.
There can be a drive (gear drive, that means different speeds) inside of the bottom bracket.
Depending on bottom bracket diameter you can separate these;
inside of the 95 mm bottom bracket you will find only EVO drives (exact name is Sturmey Archer KS3) - the gears are available via backwards pedaling for ~ 120° in this case.
Inside of the smaller (and standard) 60 mm bottom bracket you can install different drives
(but not that of the EVO);
The Schlumpf or ATS two speed drives - shifted by a heel kick sideways.
Soon the efneo 3 speed drive - it has cable shifting.
No, not at all, don’t worry - that has nothing to do with single speed brackets