One-off Blue Steel hubless-wheel ebike started out as a Schwinn

If there had been ebikes in the movie Tron, it’s entirely possible that they would have looked something like Blue Steel. The futuristic creation boasts features such as hubless wheels, full suspension and a single-sided front swingarm, although it has the soul of an old Schwinn.

If the design of Blue Steel seems kind of familiar to some readers, that’s because the bike was created by Christopher Terpstra, whose hubless electric penn-E-farthing we covered last December. Terpstra is an Illinois-based YouTuber with a degree in Industrial Design, who previously brought us a four-wheel-steering electric off-road skateboard.

He started this latest project by buying a 1960s (or possibly 70s) women’s Schwinn touring bicycle for just $10.

The handlebars, bar clamp, head tube, rear brake/lever, wheel rims, and part of the fork all made their way over to Blue Steel, along with some bits of its tubular steel frame. Chris built the rest of the ebike’s frame from scratch, out of 1-inch DOM (drawn over mandrel) steel tubing.

The hubless wheels utilize pretty much the same mechanism used in the penn-E-farthing, in which the wheel is held in place by three sets of nylon rollers which its rim passes through.

Two more rollers are used in the spring-loaded friction drive mechanism, which is spun up by a mid-mount 2,000-watt motor powered by a 48-volt/20-Ah lithium battery. That mechanism presses up against the rear tire, causing the wheel to rotate along with the mech’s powered rollers – it’s not unlike the commercially available Rubbee ebike conversion kit,

Christopher Terpstra

Both the battery and the electronic control unit are housed in a custom-made steel box with polycarbonate panels. Those panels are sanded on one side to make them translucent, and illuminated from within by strips of blue LEDs. More of those LEDs are located on the underside of the seat to light up the rear end of the bike – after all, it is called Blue Steel.

Coil-over shocks salvaged from Terpstra’s off-road skateboard link the front and rear swingarms to the frame, each providing roughly 3 inches (76 mm) of travel. That part of the design, however, proved to be particularly challenging.

“The hardest part on this build was constructing the front swingarm and steering linkage to minimize the amount of bump-steer as the suspension would travel,” Chris tells us. “I believe I went through five iterations before getting an acceptable layout.”

Christopher Terpstra

Blue Steel took Terpstra roughly 400 hours to build, and cost him about $975. The bike weighs 129 lb (59 kg) and has a top speed of approximately 30 mph (48 km/h), after which the friction drive starts to slip against the rear tire – a stiffer tensioning spring should take care of that problem.

And yes, because there are no pedals, the vehicle isn’t technically an ebike. Whatever it is, riding it definitely sounds like an … interesting experience.

“The bike has a seating position that is less than comfortable, being stretched out in a superman flying position,” says Chris. “The suspension does a good job of absorbing the large bumps. The steering itself is quite natural, similar to a traditional-style bike. The play in the rear guide wheels on the rim does translate to vibration at speed, though. Stopping the bike using only one of the original Schwinn brakes on the rear wheel is more of a hopeful suggestion than a confident halt.”

You can see Blue Steel in superman-flying action, in the following video.

If there had been ebikes in the movie Tron, it’s entirely possible that they would have looked something like Blue Steel. The futuristic creation boasts features such as hubless wheels, full suspension and a single-sided front swingarm, although it has the soul of an old Schwinn.

If the design of Blue Steel seems kind of familiar to some readers, that’s because the bike was created by Christopher Terpstra, whose hubless electric penn-E-farthing we covered last December. Terpstra is an Illinois-based YouTuber with a degree in Industrial Design, who previously brought us a four-wheel-steering electric off-road skateboard.

He started this latest project by buying a 1960s (or possibly 70s) women’s Schwinn touring bicycle for just $10.

The handlebars, bar clamp, head tube, rear brake/lever, wheel rims, and part of the fork all made their way over to Blue Steel, along with some bits of its tubular steel frame. Chris built the rest of the ebike’s frame from scratch, out of 1-inch DOM (drawn over mandrel) steel tubing.

Christopher Terpstra

The hubless wheels utilize pretty much the same mechanism used in the penn-E-farthing, in which the wheel is held in place by three sets of nylon rollers which its rim passes through.

Two more rollers are used in the spring-loaded friction drive mechanism, which is spun up by a mid-mount 2,000-watt motor powered by a 48-volt/20-Ah lithium battery. That mechanism presses up against the rear tire, causing the wheel to rotate along with the mech’s powered rollers – it’s not unlike the commercially available Rubbee ebike conversion kit,

Christopher Terpstra

Both the battery and the electronic control unit are housed in a custom-made steel box with polycarbonate panels. Those panels are sanded on one side to make them translucent, and illuminated from within by strips of blue LEDs. More of those LEDs are located on the underside of the seat to light up the rear end of the bike – after all, it is called Blue Steel.

Coil-over shocks salvaged from Terpstra’s off-road skateboard link the front and rear swingarms to the frame, each providing roughly 3 inches (76 mm) of travel. That part of the design, however, proved to be particularly challenging.

“The hardest part on this build was constructing the front swingarm and steering linkage to minimize the amount of bump-steer as the suspension would travel,” Chris tells us. “I believe I went through five iterations before getting an acceptable layout.”

Christopher Terpstra

Blue Steel took Terpstra roughly 400 hours to build, and cost him about $975. The bike weighs 129 lb (59 kg) and has a top speed of approximately 30 mph (48 km/h), after which the friction drive starts to slip against the rear tire – a stiffer tensioning spring should take care of that problem.

And yes, because there are no pedals, the vehicle isn’t technically an ebike. Whatever it is, riding it definitely sounds like an … interesting experience.

“The bike has a seating position that is less than comfortable, being stretched out in a superman flying position,” says Chris. “The suspension does a good job of absorbing the large bumps. The steering itself is quite natural, similar to a traditional-style bike. The play in the rear guide wheels on the rim does translate to vibration at speed, though. Stopping the bike using only one of the original Schwinn brakes on the rear wheel is more of a hopeful suggestion than a confident halt.”

You can see Blue Steel in superman-flying action, in the following video.