engagement of motobecane clutch

Greetings all I 'am looking for info regarding full engagement of a 77 motobecane clutch. I bought this machine for 50 bucks it is 100% complete it has not been run since 86. I have checked for spark etc cleaned fuel tank etc.. got machine to run even ides! WOW! have ridden it a bit. However the engagement between pedal drive and full motor drive is not complete I need to get this machine to be fully engaged in motor drive. I can see it not go fully into full drive mode. it does move and ride well but I can feel stress on the pedal crank. the chain has some kinks that are not yet worked out even fron some riding....I think it is too tight any idea's? thanx all you you MOBY riders out there! P.S. 77moby year 77 50v/a!

Re: engagement of motobecane clutch

I would definitely inspect your chain condition or replace it if necessary. I would also check the tension on the rear wheel nuts. When you say that you can see that's its not fully engaging, what precisely do you mean? -What part of the bike are you looking at?


Re: engagement of motobecane clutch

you have a variator clutch (congratulations)

it may be stuck it the closed positiion

learn all about it here


Re: engagement of motobecane clutch

Are you talking about the knob on the driven pulley that disengages the motor for bicycle mode? It can be hard to re-engage that properly. The manual tells you to roll the bike backwards a little while turning the knob back to moped mode. My bike is missing the rubber floorboards, so I like to look through that opening and actually watch the mechanism engage.

Re: engagement of motobecane clutch

the part behind the large belt driven pully I can see it from the right side of the bike. The lever does not go fully into the motor mode or full into the pedal mode. it is SO close but the manual says not to force it so I have not. The chain was rusted solid when I got it but has since been loosend with liqued wrench. It stil has a few small kinks in it but the wheels turn now.

Re: engagement of motobecane clutch

Thanks for the replys...Will try this people have mentioned that the teeth must be aligned perfectly for this to engage..where are these? what shall I look for when the side covers are removed? Can this mech. be lubricated? Thanx! in advance for any info!

Re: engagement of motobecane clutch


Attached is a horrible drawing of what the back of your driven pulley should look like when the bike is fully in motorized mode. The knob on the outside of the pulley moves the lever, which has a cut-out area between two teeth that fits neatly over two teeth on the sprocket. If you try twisting the knob when the teeth aren't all lined up, the lever isn't going to go in. If you push too hard when the teeth aren't lined up, you can pop the spring off the lever (as I did the first time.) I had to watch it engaging for a while, but now I know what it's supposed to feel like. If the teeth aren't lined up right, back the knob up, roll the rear wheel a little as if the bike were rolling backwards, and try again.

Re: engagement of motobecane clutch

Just a tip, replace a rusted chain. A chain is alot easier and cheaper to replace than worn out sprockets.


Re: engagement of motobecane clutch

Thank you all for your info! Very helpful...Does anyone know if the moped junkyard chains that are advertised are the corect lenght? Or does one have to knock links out to make it fit? Thanks again all!

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