Hi everyone -
For quite some time I have been a sort of collector of vintage mopeds as I find them very fun. However, these old 2-stroke machines require quite a bit of maintenance and/or tuning, and that's something I have to admit I'm just not very good at. As a result, I have largely given up keeping any of them running and they are collecting dust in storage. I have been thinking for a long time about converting one or more of them to electric and I've decided to start with a '77 JC Penney Pinto.
For those who are unfamiliar, the Pinto looks like this:
The Pinto was a variation of a common design made by Puch, which featured a 50cc single speed engine driving the rear wheel by chain on one side of the bike with pedals driving the rear wheel on the other side of the bike. Given its original design, swapping out the 50cc engine for an electric motor should be a rather simple way to make the conversion possible.
Here's an image of one that has been stripped down:
As you can see, there are a lot of options for where to mount batteries, controllers, etc. I would love to be able to keep the gas tank and perhaps somehow convert it into a battery pack, as the tank provides a major part of the styling of the machine. Otherwise I hope to hide as much of the equipment in saddle bags hanging from the rear rack to keep everything looking as original as possible.
I'm a newbie to all of this, and so I'm hoping to get the input of you more seasoned folks to make sure I'm not thinking about the parts of this project the wrong way. So here's where I'm at:
Requirements
Cruising speed: 30-35 mph (50+ kph)
Top speed: 40-45 mph (65+ kph)
Range: 30 miles/50km would be nice. 50 miles/80km would be great. 100 miles/160km would match the original tank of gas but is probably excessive for my needs. This is less for commuting and more for just riding around for leisure on sunny days.
The rear wheel size is 17" and sprockets are available from 36-60 teeth, so I'm thinking the gearing will be no problem to match with a motor in the 3000-5000 rpm range.
I'm not too worried about the cost of this project, though I don't want to go totally nuts. I'd be ok in the $1,000 range but would shy away from $2,000...
Motor
Right now I'm leaning toward the Golden Motor HPM3000B: http://www.goldenmotor.com/frame-bldcmotor.htm
3kw and a speed of 4000rpm would both work well, and I think it would be trivial to get it mounted to the Pinto's frame.
I'm not well versed on what other options I should consider here, but that motor seems to offer a pretty good value for its specs, and the specs look like a good match.
Controller
This is where I'm pretty clueless. I'm assuming that I would just use the controller provided by Golden to match. What do I need to consider for this?
Battery
My big question here is what capacity battery I should be considering for the requirements I listed above. I was leaning toward doing a 40AH setup, and I'd like to split that into two pieces so that one each can be kept in the saddle bags. I could also just do one pack mounted to the rear rack, but that would raise the center of gravity a bit. I'm guessing that 40AH would not fit in that old gas tank, even if I could figure out a way to get them in there. I'm not sure if I should be looking to build some custom packs or just find something pre-made. Any suggestions?
Accessories
I'd really like to figure out a way to keep the original grips/controls, but those are obviously designed for a cable-actuated throttle. Do I have any hope here?
Is regenerative breaking/deceleration something to even consider?
I know I can find 48v light bulbs to swap into the existing fixtures, but I'm thinking I might want to go with LEDs. Those are not so easy to find in the 48v range. Should I consider a step down so that I can just use standard 12v bulbs/horn/etc?
Thanks in advance for everyone's input. I'm going to keep reading what other threads I can find on related projects, but I'm excited to get some feedback on my plans so far so that I can get started.
For quite some time I have been a sort of collector of vintage mopeds as I find them very fun. However, these old 2-stroke machines require quite a bit of maintenance and/or tuning, and that's something I have to admit I'm just not very good at. As a result, I have largely given up keeping any of them running and they are collecting dust in storage. I have been thinking for a long time about converting one or more of them to electric and I've decided to start with a '77 JC Penney Pinto.
For those who are unfamiliar, the Pinto looks like this:

The Pinto was a variation of a common design made by Puch, which featured a 50cc single speed engine driving the rear wheel by chain on one side of the bike with pedals driving the rear wheel on the other side of the bike. Given its original design, swapping out the 50cc engine for an electric motor should be a rather simple way to make the conversion possible.
Here's an image of one that has been stripped down:

As you can see, there are a lot of options for where to mount batteries, controllers, etc. I would love to be able to keep the gas tank and perhaps somehow convert it into a battery pack, as the tank provides a major part of the styling of the machine. Otherwise I hope to hide as much of the equipment in saddle bags hanging from the rear rack to keep everything looking as original as possible.
I'm a newbie to all of this, and so I'm hoping to get the input of you more seasoned folks to make sure I'm not thinking about the parts of this project the wrong way. So here's where I'm at:
Requirements
Cruising speed: 30-35 mph (50+ kph)
Top speed: 40-45 mph (65+ kph)
Range: 30 miles/50km would be nice. 50 miles/80km would be great. 100 miles/160km would match the original tank of gas but is probably excessive for my needs. This is less for commuting and more for just riding around for leisure on sunny days.
The rear wheel size is 17" and sprockets are available from 36-60 teeth, so I'm thinking the gearing will be no problem to match with a motor in the 3000-5000 rpm range.
I'm not too worried about the cost of this project, though I don't want to go totally nuts. I'd be ok in the $1,000 range but would shy away from $2,000...
Motor
Right now I'm leaning toward the Golden Motor HPM3000B: http://www.goldenmotor.com/frame-bldcmotor.htm
3kw and a speed of 4000rpm would both work well, and I think it would be trivial to get it mounted to the Pinto's frame.
I'm not well versed on what other options I should consider here, but that motor seems to offer a pretty good value for its specs, and the specs look like a good match.
Controller
This is where I'm pretty clueless. I'm assuming that I would just use the controller provided by Golden to match. What do I need to consider for this?
Battery
My big question here is what capacity battery I should be considering for the requirements I listed above. I was leaning toward doing a 40AH setup, and I'd like to split that into two pieces so that one each can be kept in the saddle bags. I could also just do one pack mounted to the rear rack, but that would raise the center of gravity a bit. I'm guessing that 40AH would not fit in that old gas tank, even if I could figure out a way to get them in there. I'm not sure if I should be looking to build some custom packs or just find something pre-made. Any suggestions?
Accessories
I'd really like to figure out a way to keep the original grips/controls, but those are obviously designed for a cable-actuated throttle. Do I have any hope here?
Is regenerative breaking/deceleration something to even consider?
I know I can find 48v light bulbs to swap into the existing fixtures, but I'm thinking I might want to go with LEDs. Those are not so easy to find in the 48v range. Should I consider a step down so that I can just use standard 12v bulbs/horn/etc?
Thanks in advance for everyone's input. I'm going to keep reading what other threads I can find on related projects, but I'm excited to get some feedback on my plans so far so that I can get started.