Motobecane interchangeability

I am building up a moby 79 50v i just got and am trying to figure out the interchangeability of parts from a av 7 to av 10. From reading I am pretty sure that the variators and exhausts are interchangeable but correct me if I am wrong. I am also wondering if the cranks are interchangable (I think I read this somwhere) as well as the cylinder heads. Also on what mbk bikes have the av10 motor i am assuming the 51 but there aren't any variator listings in that category. Come tho think of it this might make a good wiki addition.


vive le resistance


Re: Motobecane interchangeability

You can use your variator but you have to replace your fixed cheek. You can use your cylinder head, you can use your exhaust but it might break, they don't fit perfectly and i broke mine doing this. the case hardware does not transfer, so you'll need a way to mount the lower engine tension spring and exhaust.

Re: Motobecane interchangeability

the crank swaps, but the av10 is normal thread and the av7 is reverse thread on the magneto side

cylinder heads swap too but not cylinders

Re: Motobecane interchangeability

old AV10s are still points but those are pretty rare, in that case the cranks are the same. Someone told me that the AV10 stock crank is stronger than the AV7 but I'm not sure.

Re: Motobecane interchangeability

For a little clarity the plan was to put a 70 kit and a Doppler av10 exhaust on my av7 which i just picked up from treatshq and i heard that the av7 cranks like to break and was kicking around the idea of picking up a doppler av10 crank when/if it broke and possibly an high compression av10 head and was making sure that was kosher before I threw down the euros.

Thanks for the help

P.S. Elliot you have a sexy ass yellow moby.

Re: Motobecane interchangeability

av10 stock crank snapped.

yes they are stronger but also snap if u don't build right!!! and also stuffed at least the newer ones.

anyways that crank snapped cuz i was running a 2 ball variator setup at high rpms 9000+ over extended periods of time. DONT RUN 2 BALL ON A FAST MOBY!!!

av7 cranks also snapped in the same fasion but sooner with the 2 ball

i still dig 2 ball works great on stock mobys just not super mobys.

i currently run the av7 crank on my av10 setup with no proobs and no snapping has been months of hard riding and no probs. keep that shit in balence and u wont snap cranks!!!

have fun

Re: Motobecane interchangeability

Dear everybody.

Tom is dead serious about mopeds!

You gonna come ride with us thursday night?

Re: Motobecane interchangeability

I'll try Mike i have band practice every thurs but am trying to work around it so I can ride with you guys. Until I work it out any other night I would love to ride with you guys.

Re: Motobecane interchangeability

The picture reminded me, has anyone in the states seen a place selling the replacement bearing set that was in stock seems like everyone's out. Also I gotta say I love all the help I am getting from you guys thanks!

Re: Motobecane interchangeability

Every place I've checked is out. I have a standing order at Treats when they do come back in. Must be the high price of oil affecting availability.

Re: Motobecane interchangeability

ah! my old ass AV10 doesnt have a stuffed crank. what kind of crap is that...

you can use 2 balls on a fast moby just so long as you replace the (normally) standard 3 ball ramp plate with a 4 ball.

Re: Motobecane interchangeability

true and that is a great setup for low bucks

also all the bearings we get now are made in korea if u notice the ones on that stock av10 crank are made in germany, i want some of those not the korean ones, i went to korea, real hot, alot of working overtime, alot of sojun.

Re: Motobecane interchangeability

Anyone try hitting up a bearing house?


Re: Motobecane interchangeability

American bearing distrbutors don't carry the motobecane bearing because it's a variant of a standard bearing that no one else uses. It has a chamfered inner edge on the inner hole. You can get them custom made if you can find someone to do it, but it'll be easier to just order some from europe. Get two and sell one set to someone else, and recoup some of your cost.

Re: Motobecane interchangeability

I have a lot of questions...sorry for the barrage.

Is there a French web-site you get the replacement bearings from, or just ebay?

Are they stronger than the stock bearings? Also do you have a part number?

Re: Motobecane interchangeability

quarterkick and '77 also carry them.

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