Chain snapped on Motobecane

Motobecane Rookie /

Hi all,

I managed to snap the chain on my moped, 1977 motobecane 50v. I believe it was from this chain of events:

-I broke and then replaced the pulley on the moped (this piece -

-While / after repairing the pulley, the chain must've been too loose, and it popped off while riding.

-I adjusted the position of my back wheel (brought it back by a small amount) so that the chain wouldn't pop off again, and after ~2 miles of riding the chain snapped.

My thought is that moving the tire back made the chain too tight, and for that reason it snapped. I did not hit anything while riding at the time of the chain snapping.

My question is - should I be looking into any specific chain for the 1977 motobecane v50, or will a google search for 'moped chain' bring up a bunch of results that will all fit on my moped? I counted the number of links on the chain and it was 54 if i counted correctly, although I'm not sure if I lost any links of the chain when it snapped.

Thanks in advance,


Re: Chain snapped on Motobecane

Trevor "Scraps" Arms /

You've ruined it, better just give it to me

JkJk, Just grab a 415 HD drive chain and a chain breaker for drive chains, make sure to leave a little less than an inch of play when tightening it, also make sure your pulley sprocket and rear wheel's sprocket line up straight.

Re: Chain snapped on Motobecane

I use #41 chain that I got from advance auto,

it was 10ft. with a master link included for less than $20.

I've heard of people using 415, 418, 420 and #41.

You can use a grinder and punch to remove the pin in the link

if you don't have a breaker.

Re: Chain snapped on Motobecane

Motobecane Rookie /

gonna get the 415, thanks for help

Re: Chain snapped on Motobecane

If you can swing it now would be a good time to replace the rear sprocket too. Everything will be new, matched and wear together evenly that way. Then for added insurance get a good chain like a Regina race chain to protect your investment!

Re: Chain snapped on Motobecane

I also use #41 chain from tractor supply. Less than $20 for 10 feet. I can make two chains from it. (edited)

Re: Chain snapped on Motobecane

I have only used #41 chain on Mobys. Check that your sprocket on the rear is not worn pointy tips on the teeth and the scallops are not worn open or the chain will skip and mess up even if it is new.

When you install the chain make sure the rounded part of the C is on the top run of chain and pointed towards the front of the bike or it can get unclipped while you ride.

When adjusting the tension of the chain always start with the motor side and move the wheel back so there is 1/2 inch (12,7mm) total up and down movement of the chain at the center of the top length. Less will wear out the chain and gears, more will wear the tips of the gears and could jump the chain off the sprockets. Make the setting with the bike fully laden - like your ass on the seat and check it - so there is play with the suspension loaded rather than free standing.

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