Where to begin...?

ElectricBarry

10 µW
Joined
Feb 5, 2023
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5
I picked up a very inexpensive Honda Express 50cc Moped for my son and I to get running while stuck indoors for the winter. After digging into it, it is no longer viable as a gas power rebuild. Instead of scrapping the project, we decided we'd like to try and convert it to electric but we have NO idea where to start (size of motor, other necessary components, etc).

We've read a few posts about similar builds but are still out of our depth. It seems like we can go whole hog and strip it down to the frame and add everything new, but we're hoping to keep some of it's original look in tact (maybe hiding the components inside the block and gas tank). Looking for any assistance/knowledge as to where to begin or at the very least some input about what we can keep/re-use (wiring, cables, etc) vs what has to go.
 
Do you want someone to come help you with this (virtually or physically)? (that's what this Help Wanted & Offered subforum is for) If so, you should post at least your general location to get people near enough to you to help.

Or do you want the forum members in general to help you work out what's needed so you can complete the project yourself? (if so, I can move this to the Motorcycle/etc subforum for you)
 
I suppose we're more looking to complete it ourselves, so the other subforum would be best. I'll come back to this one if we get in over our heads.
 
The main aspects we're trying to determine is what size motor should we be using to max out speed at 35-40mph for this and best options for battery life.
 
The main aspects we're trying to determine is what size motor should we be using to max out speed at 35-40mph for this and best options for battery life.

QS motors is a good place to start. The battery part will be the more challenging part, as it probably will need to be custom built to fit that particular frame.

Add photos so we can see the bike
 
The main aspects we're trying to determine is what size motor should we be using to max out speed at 35-40mph for this and best options for battery life.
Do you already have determined the power requirements for this, on your particular terrain, road, and weather conditions?
If not, you may want to use the ebike.ca motor and / or trip simulators to do this. It will also give you some basic guesstimate of wh/mile so you can figure out what size battery will be needed to get the range you need under those conditions and usage.
 
Here is the bike as of now. We are open to suggestions for type of motor and placement given the existing structure of the bike. I have access to almost any metal fab tools, but we're not trying to create a polished art scooter, so hopefully we can all put our brains together for a way to do this mostly at home.
 

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What is the drivetrain inside the swingarm casing? Belt, chain and/or gears? I've seen people removing the combustion cilinder and attaching an electric motor to the crankshaft.
 
I haven't opened it all back up since last year, but here are some manual clips. Happy to provide more.

Will consider a hub mount also. My metal skills and tool access would definitely be better suited to creating a new swingarm or shock mounting point rather than boring out the entire engine case.
 

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Probably best to disassemble and empty the engine case. Get rid of all the stuff connected to the crank shaft and starter assembly. Then directly mount an electric motor to the "drive chain" in the case. You'll have to work out what the final reduction is to see what gear ratio/sprocket size(s) you want to use for the acceleration and top speed you aim for. I think a simple cheap and cheerful MY1020 motor would do nicely. Get the 72V 3000W version, build everything together and then get or build a battery pack for it.
MY1020 72V 3000W sinewave
 
My two cents just seeing the pics of the bike, you‘ll want a lithium ion pack that could fit where the gas tank is. You’ll get higher energy density than you would with lifepo4 cells, packs are widely available in different sizes and you could even build your own if you wanted to. I myself would opt for a hub motor, being that it’s a small frame and the old drive train is so integrated to the casing that it would require serious modifications anyways to adapt anything. Best imo to remove it altogether and convert the rear wheel to hub motor. That’s just off the cuff from what I can see. Cheers
 
Here is the bike as of now. We are open to suggestions for type of motor and placement given the existing structure of the bike. I have access to almost any metal fab tools, but we're not trying to create a polished art scooter, so hopefully we can all put our brains together for a way to do this mostly at home.
fun little bike....you could put a battery where the rack is...this will be a fun project for you guys...
 
My two cents just seeing the pics of the bike, you‘ll want a lithium ion pack that could fit where the gas tank is. You’ll get higher energy density than you would with lifepo4 cells, packs are widely available in different sizes and you could even build your own if you wanted to. I myself would opt for a hub motor, being that it’s a small frame and the old drive train is so integrated to the casing that it would require serious modifications anyways to adapt anything. Best imo to remove it altogether and convert the rear wheel to hub motor. That’s just off the cuff from what I can see. Cheers
deff would do a hub motor also...
 
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