Hubless-wheel electric penny farthing is a one-of-a-kind masterpiece

Although their advantages over conventional bicycles are debatable, hubless-wheel ebikes certainly look futuristic. Penny farthings, on the other hand, definitely do not. It only makes sense, then, that YouTuber Christopher Terpstra would combine the two in his one-off penn-E-farthing.

Terpstra lives just outside Chicago, and has a degree in Industrial Design from the Milwaukee Institute of Art and Design. He worked as a retail fixture design engineer for 15 years, and first came to our attention back in 2015 when he developed a four-wheel-steering electric off-road skateboard.

Some of his other projects – featured on his Chris Makes Stuff YouTube channel – have included a six-wheeled garden tractor, a plastic-tube electric outboard motor, and a stretched chopper bike.

His latest creation, the penn-E-farthing, is basically a penny farthing bicycle with a hubless front wheel and a motorized rear wheel. It sports a custom tubular steel frame, a custom laminated maple/oak plywood front wheel, plus a 350-watt motor, battery and rear wheel scavenged from a Razor MX350 Dirt Rocket children’s electric motorbike.

The penn-E-farthing’s front wheel passes through three sets of rubber rollers – one set can clearly be seen at the left

Christopher Terpstra

The 52-inch front wheel is unpowered, and is held in place by three sets of frame-mounted rubber rollers which its rim passes through. Its solid rubber tire is composed of cut-apart V-belts (typically looped through pulleys in mechanical systems) which were glued and nailed to the rim.

“I knew that making the wheel in a layered ply construction would be the strongest approach, but I didn’t fully grasp the amount of time it would take to do,” Terpstra told us. “Being an amateur woodworker with dated tools and homemade jigs also added to the fun. After designing it in CAD, I was semi-confident it would work, but you never really know until you hop on and twist the throttle.”

Hop on and twist the throttle he did, though, and the penn-E-farthing worked just as intended. That said, Chris doesn’t plan on making any others like it for paying clients – it was just something that he was drawn to build.

The motor, battery and rear wheel came off a Razor MX350 Dirt Rocket motorbike

Christopher Terpstra

“My inspiration for the bike is a mix of Dr. Seuss creations as well as the movie Wild Wild West,” he said. “In that movie, the main character Artemus Gordon is an inventor who created a steam-powered flying highwheel bike. I always thought that was cool and thought I could build it. Although this one doesn’t fly … yet.”

The build process – and the first shaky ride – are documented in the following video.

INSANE E-bike Penny Farthing – Hubless, Motorized, High Wheel, electric bicycle build


via Hacker News

December 16, 2023 at 10:57AM