Swapping a 415 chain for a 420.


Well-Known Member
Jan 5, 2020
Found out what the problem was making the grinding teeth chatter. Something inside I was horsing my bike down the street then all of a sudden sounded like the chain was eating teeth off the sprocket lot of vibration then thud no motor stop dead something inside got chewed up and I know by the horrific sound it's never gonna start again.

I hoped that Bikebury new CDI was going to get in to try and resurrect another motor of two with amazing electric current, but again they mailed it some other address in town after giving me a USPS Track number then canceled the order then ship it FedEx after I paid them $30.00 extra for 2-day shipping now it's been 2 weeks still no dream product hope of resurrecting a dead motor.

When your f*** it just continues to get more f*** up it ain't gonna stop.

I have not taken the motor apart as yet but what in the hell would of gone out like ripping a chain over a sprocket noise?
Just look at where the chain attaches to the motor.


Active Member
Nov 5, 2019
Think I took it off not sure which motor been working on. Helico gears don't know the motor had them what are they?
I think he might be asking about the gears under the clutch cover. Must be a fancy mechanic lol. Do you have any grey coupon, sir? I need some for my corn dog.

Karl Snarl

Well-Known Member
Sep 20, 2019
My chain broke again in 2 different places, because I was too damn lazy to take up the slack. For some reason I put the chain on proper tension the I guess the wheel pulls out of the hub bracket just 1/4" inch which now transforms into 2" of slack.

So, I'm ordering a spring-loaded tension assembly so if it slips it will automatically adjusted. Now, I'm beefing the chain up to a 420 but, they have different lango there is D.I.D, MX, MC other indicators which one do I need? How many links or I guess I got to measure my stock 415 just how long if I can get off my lazy ass.
Also, looking at the pictures the rollers look like they can take a 420 an additional 5mm width but no one gives specks on width anyone have a spring tension know what width?

So, I'm thinking instead of a smooth roller wheel to spend another $10.00 to buy a gear roller that would slide in, any comments on that one?

Also, I would like to keep my chain guard on, but all the pics showing the spring assembly show it without the chain guard on the bike, will it fit, or do I need to buy a tin cutter and little the guard down to make it fit?

Hurry with your answers I need to order right away to get back on the road do so some fart biking.
Hey bro, 420 is always better. Its why I ride a smoker. People think that cloud is from my bike.


I run 420 chain. Just make sure the space is there in the housing for the clutch lever and final drive cog. I use, um RK tasago, i think it's called. Great chain, logo is a big red "RK". Last's for ever and a day, and in 4 years I've never had to replace it from wear, just a smaller sprocket. I save chains, and reuse them when I use tht sprocket size again. Which never happens when I dial a bike in, so i have a bunch of chains hanging up, waiting. lol