Jennifer Holt, currently a physics grad student at Ohio State, made this motorized mountain bike herself–she even made the frame so it could hold all the components.  Check out her website, JennTech, Science From Scratch, where she’s posted more specifics, pictures of the electronic parts, and will soon post the schematics for the bike with its 48V motor and homemade lithium battery pack. She limited the top speed to 30mph, and admittedly isn’t very good at riding it yet–she’s already fallen off and broken her elbow. Video of it in use (pre-broken elbow) after the break.

Found via Make:Online.


  1. Nice machine, although I worry that people confuse this kind of home brew electric moped with the bicycle path legal electric assist bikes that are limited to 20 MPH. If you can accelerate like she can (without pedaling) it is unrealistic to expect to be legal on bike paths or mixed use trails. Pretty much shouldn’t be legal anywhere an actual moped wouldn’t be legal, like mountain bike trails versus motorcycle trails.

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