# Quick Sprocket Question



## arachnyd (Aug 26, 2011)

I've been researching everywhere where to find the right sprockets.

IT looks like there are really only industrial sprockets available that fit the electric motor hubs, but these don't align quite perfectly with motorcycle chains. All my research says you HAVE to use motorcycle chains.

So that creates a problem. As of now I have 428 chain, which has plenty of strength for an electric bike, and a rear 428 sprocket. For my front sprocket, 40 or 41 ansi SHOULD work, right? Does it matter if I do 40 or 41? is once preferred over the other?

Using Mars/Motenergy ME1003. Thanks!


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## frodus (Apr 12, 2008)

Not sure if it's an option, but ANSI #50 chain (which you can find industrially) is the same width and pitch as 530 motorcycle chain. In fact, it's the ONLY one that fits without modification of the sprocket.

I got my rear sprocket from Sprocket Specialists and my front sprocket from Surplus Center. 

If you have to use 428 chain, you might have to machine something down (so the width matches). Maybe Zero Motorcycles has a sprocket for you?


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## arachnyd (Aug 26, 2011)

frodus said:


> Not sure if it's an option, but ANSI #50 chain (which you can find industrially) is the same width and pitch as 530 motorcycle chain. In fact, it's the ONLY one that fits without modification of the sprocket.
> 
> I got my rear sprocket from Sprocket Specialists and my front sprocket from Surplus Center.
> 
> If you have to use 428 chain, you might have to machine something down (so the width matches). Maybe Zero Motorcycles has a sprocket for you?


I could go the 50 route, but the 428 chain does not need to be machined down. Thats the benefit of the 428 over the 420, as the 420 requires the 40 and 41 to be planed, the 425 and 428 do not. If I go to the 530 route, then I have to deal with the challenge of tracking down a 530 or 50 sprocket that fits the rear wheel mounting. I can go that route if necessary, but everywhere I've read says the 40/41 + 428 works well, I just can't figure out if the 40 or 41 is a better fit to reduce long term chain wear, or if they are completely equal, then I'll just go with the 40 because its convenient! haha.


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## frodus (Apr 12, 2008)

The roller sizes are different on 40 and 41. 41 the width is different. I'd choose 40 over 41.

Look here:
http://www.azusaeng.com/chain/mcyclchn.html


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## RIPPERTON (Jan 26, 2010)

Why cant you just get a 428 front sprocket.
Its just a half inch pitch and is an industry standard.
I would stick with the 428 chain as it would be quieter than the 520/530 and also available in oring (Honda Posty bike).
You get the sprockets with a big shoulder and a small pilot hole.
You first drill a 5mm hole off center as a keyway and then bore it to the shaft size. Then square off the keyway with a file.


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## frodus (Apr 12, 2008)

So they sell 428 fronts? I thought they were all splined for motorcycles... Haven't seen any that are made to fit a motor shaft.... Would be awesome if you had a source!


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## arachnyd (Aug 26, 2011)

frodus said:


> The roller sizes are different on 40 and 41. 41 the width is different. I'd choose 40 over 41.
> 
> Look here:
> http://www.azusaeng.com/chain/mcyclchn.html


More exciting with your source is the discovery that 40 and 425 are identical. I never saw that any other place, but I'd have no problem going to a 425. I think I'll probably go with a 40 and then just move my chain over to a 425 at some point. Thanks for the link- VERY VERY helpful.


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## arachnyd (Aug 26, 2011)

RIPPERTON said:


> Why cant you just get a 428 front sprocket.
> Its just a half inch pitch and is an industry standard.
> I would stick with the 428 chain as it would be quieter than the 520/530 and also available in oring (Honda Posty bike).
> You get the sprockets with a big shoulder and a small pilot hole.
> You first drill a 5mm hole off center as a keyway and then bore it to the shaft size. Then square off the keyway with a file.


Thats an idea worth considering. Since 428 is used on a lot of small bikes, I'm guessing there are 12-14 tooths readily available. Takes some manufacturing, but your right its probably much better than going to the 530... although the 425 has my interest peaked. 



frodus said:


> So they sell 428 fronts? I thought they were all splined for motorcycles... Haven't seen any that are made to fit a motor shaft.... Would be awesome if you had a source!


they don't- you have to bore out the shaft and cut your own keyway.... as explained!

Thank you both!


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## frodus (Apr 12, 2008)

Oh, I guess I just never realized they have "blanks" with only a pilot hole in them. Cool! Good luck!


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## arachnyd (Aug 26, 2011)

frodus said:


> Oh, I guess I just never realized they have "blanks" with only a pilot hole in them. Cool! Good luck!


I think what he was saying was to take a normal motorcycle sprocket, drill out your own pilot hole with a drill, then bore out the center , then file out the pilot hole to turn it into a keyway.

It certainly "sounds" easier than its going to be, but its theoretically doable.


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