Hello everyone! I am planning to convert my old Schwinn tandem to an ebike. My wife found it in the trash (!!) about ten years ago, and I have had a ton of fun with it. I got new tires, seats, and added an internal hub three speed, but it is otherwise stock. Chrome fenders, side pull front caliper brake, rear coaster brake. In the summer I take it to the campground, sometimes with an old trailer to pull people and things around. For Holloween, I have zip-tied a six foot home depot skeleton to the back, including feet on pedals, with some battery floodlights, and it looks like I have a skelly as a stoker. My kids are a bit older now - teens and preteens - and I'd like to share with them, but my area is hilly enough to make riding the thing a chore, even for an adult with strong legs.

This will be my first ebike conversion, but I have some bike mechanic skills and am an electrical engineer by training, software engineer by trade. I did have a consultation with Mr Nerd Out himself, about a few topics, but on this one he basically said "any bike can be converted to a mid drive ebike!"

I had planned to use a hub drive front wheel, but am going to give a go at mid drive. If it doesn't work out I will use the mid drive on a more modern, normal bike.

Right now I am considering a Bafang unit. Not sure which size. Bigger is better I suppose but also this doesn't need to be a racer, more of a hauler.

One concern is the bottom bracket(s). I might have to just try to fit it, and be ready to get spacers and such as needed.

I am considering mounting the motor on the rear bottom bracket. The front would be more straightforward, as there is only one chainring, but I would like to keep the stock look as much as possible. On the rear, I might not add any pedals at all, and just have a foot platform. Half the time the rear passenger only pretends to pedal anyway.

For the rear double chainring, I might have to come up with something custom to mount it. I suppose I could have different size chainrings?

Regarding gearing and coaster brake. I should change that out. Would it even work with a coaster brake? The "fancy" model of this bike came with a rear derailleur and was a five speed, so there should be plenty of clearance to add a freewheel or cassette (which are different? but I am not sure how).

I probably want more robust brakes anyway. I wonder if I should try to mount a pair of disk brakes, they are pretty mainstream these days.

That's what I can think of now. Anyone have any thoughts or comments?? :)

Photos show a bike just like mine, and some shots of the service manual, showing the one piece crank, the idler assembly for the front chain, and the two-chainring rear crank. (Maybe I don't use any of those parts and instead use a modern crank assembly with two chainrings?)