It's crazy what you can cook up with an old bicycle, an electric motor off the internet, basic electrical and mechanical know-how, and a lot of guts and patience. Indeed, while rules and regulations surrounding e-bikes are indeed a lot more lax in the U.S. compared to other parts of the globe, what we have here today is certainly not road legal.
Nevertheless, it's a remarkable representation of just how much performance you can eke out from an electric motor. Showcased in a YouTube video by a channel called All Things Electric, this dude transforms his old Trek mountain bike into an electrified machine that's packing some serious power.
As you can see, the bike is thoroughly a backyard build. I mean, the dude even shows us how he fabricates makeshift foot pegs that mount directly onto the rear axle. The bike still has its stock cranks and pedals, but doesn't have a chain. Needless to say, this contraption would make for quite a messy accident should things go sideways. Luckily, the build seems to be going smoothly.
Diving into the specifics, the DIY electric bicycle employs a 5,000-watt hub motor with a peak output of 14,000 watts. That's approximately 19 horsepower—about the same as a 200cc gasoline-powered motorbike. On top of that, the bike runs on a custom-made battery pack, which, judging from how bulky it looks, is probably heavier than the bike itself. The entire system is managed by a Sabvoton 72150, something you can pick up off the internet for little more than $200 USD.
As for the bike itself, it runs on 29-inch wheels, which give it the stability it needs to hit such high speeds. According to the builder, real-world tests have shown a top speed of 56 miles per hour, which is actually pretty terrifying for a bike like this. According to the builder, the bike can hit 74.9 miles per hour when doing static tests.