Citizens of Philadelphia, beware: You may see a grown man whizzing by you on a skateboard, doing 20 mph. That would be PopSci staff photographer John Carnett, and in case you don’t get a good look, it’s a souped-up, motorized board he built from the ground up.
Carnett wanted to create a motorized skateboard that would be superior to commercial models—a fast, hot-looking board that ran on all terrains. He started by cutting a shiny 44-inch-long aluminum deck and bending the ends and side rails. So that it could move easily from pavement to trail, he outfitted it with durable axles and 8-inch inflatable knobby tires.
Then there was the matter of installing a disc-braking system and a 500-watt electric motor. And since no wheel bearings existed that fit both the truck axle and his custom drive system, Carnett had to cobble together and weld an aluminum adapter plate to make everything fit. Then he attached a box to the underside that holds the motor controller and four batteries; when the first two die, the board can go another 8 miles on the backups. Or he can let the board do the climbing work, and then power it off and freewheel downhill. Either way, it’s the sweetest ride on the road—or off it.
How it works
- Dept: You Built What?!
- Cost: $800
- Time: 3 days
The motor runs on 24 volts from two sealed lead-acid batteries, and drives the back wheels with a chain. Carnett plans to upgrade to polymer lithium-ion batteries to shave off about 12 of the board’s 60 pounds.
The rider accelerates using a pistol-like trigger connected to a control box with a wire. The trigger and wire can be coiled and stowed when riding freewheel, so no electric parts get damaged or pose a danger in the event of a crash.
To slow down, the rider squeezes a grip similar to a motorcycle brake held in the other hand, activating a rear-wheel disc brake that can stop the board far quicker than the regenerative-braking systems electric boards typically use.
This story has been updated. It was originally featured in the March 2008 issue of Popular Science magazine.