TinyBike — Part 2

When I left off, I had a small electric bike. And it worked. It was slow, and only ran for about 15 minutes, but it worked. So I immediately tore it apart.

The insides aren’t bad, really. My only real complaint is the plastic foot pegs. I’ll just have to replace them. Right below the seat there’s a steel panel where the old motor mounted. My new motor is face mount, rather than side mount, though, so a little bit of fabrication is called for.

A little scrap metal later, and I had a motor mount. Man, I really love welders. It’s like a permanent hot glue gun, but for metal. What’s not to love? But moving on.

The fairings are blue. I don’t really do blue, so I sanded them down and replaced the nice, even color of thermoformed plastic with a shoddy paint job. I really don’t want to re-paint it (as I hate painting), so I’ll probably just cover it with stickers.

The bike originally ran off of two 12V 7Ah lead-acid batteries. I wanted 36V. And since my lithium pack is far from ready, I just added in another lead-acid cell. The only problem is that there isn’t any room for it on the frame, so  made a small battery holder out of some angle iron.

It’s really not the nicest thing in the world (and it’s only tack welded in place) but it’s plenty strong and no one will see it anyway.

At this point I did some bench testing of my sketchy Chinese motor and controller, and learned that my motor was awful and broken. So I returned it. And I’m still waiting for the replacement. But being that I’m impatient…

…I put the whole thing back together with the original motor and an upgraded controller.

And it drives! It will do about 29mph peak, and has about a 7.5 mile range. Not to mention that it doesn’t look all that bad, but I do need to paint the last few bits of blue.

Hopefully I can get the brushless motor in place before Maker Faire Detroit (and the associated PPPRS race), but for now it’s alright enough.

Still coming up:

1. Speed trials
2. Range testing
3. Races!
4. MOAR POWER
5. Lithium

How much of this can I accomplish in my last week in Madison? We’ll find out.

When I left off, I had a small electric bike. And it worked. It was slow, and only ran for about 15 minutes, but it worked. So I immediately tore...