Modified Electric Minibike

Motivation

​Freshman year of college meant leaving my beloved cars and most of motor-sports behind. I could have picked up a bike to get around campus, but it seemed more fitting to fill the need with a new project.

The Bike

I picked up a broken Razor electric minibike chassis off craigslist for about $50. Ordinarily these are children’s toy scooters. They have about a top speed of 8mph and aren’t meant to tow around much more than a 100lbs. However the chassis itself is stout enough to support a larger rider and swing arm mounted motor location looked to be able to accommodate a bigger motor without extensive modification.

Build

Being at school without a garage of tools, any serious fab work was out of the question… I would pretty much only be able to assemble an assortment of parts. So I found a motor that looked like it would mount up to the stock bracketry without modification and ordered the following:

• 750W 36V MY1020 Electric Motor
• 48V 50amp LB37 Controller
• 48V Throttle
• 4x 12V/12A UB12120 SLA Batteries
• 48V 3.0 amp XLR Battery Charger

The motor mounted up as expected. Three of the four batteries would have mounted just fine in the stock locations, but trying to cram four into a space meant for three required some “reforming” of the front case behind the front fairing and a couple of large zip ties holding the two upper batteries together. It was a bit kluged for my taste, and if I could do it again (with access to some power tools) I’d fabricate a new cage to hold everything without much trouble. All in all it worked out just fine and I wasn’t worried about anything coming loose or undone, simply that water and condensation might find their way in.

Results

​The bike would hold about 25 mph, was relatively quiet and a single charge lasted just long enough to get me to class and back. It fit the bill perfectly. Picture

Reality Check

​Unfortunately it only took two weeks before my dorm’s residential college director informed me I could not lock up the scooter near an electrical outlet in front of my building. As it turned out, the bike racks were too far away from an outlet and I lived on the 4th story of an elevator-less building. Luckily it only took me a week to sell the bike. I put an ad up on craigslist and heard back from gentleman with an interesting application. He was looking for a gear-less option for his son, who had a bad foot and couldn’t shift. He assured me they’d be taking every safety precaution and made me an offer I couldn’t refuse. I ended up turning a small profit. Seeing how the whole project was really just an excuse to tinker on something new anyways, I’d’ call it a success.