Bicycles

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

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The one-of-a-kind Blue Steel – which we realize is technically not an ebike
Christopher Terpstra
A close look at the friction drive mechanism
Christopher Terpstra
Both the battery and the electronic control unit are housed in a custom-made steel box with polycarbonate panels
Christopher Terpstra
The one-of-a-kind Blue Steel – which we realize is technically not an ebike
Christopher Terpstra
This ebike has got the blues
Christopher Terpstra
Blue Steel's one-sided front swingarm
Christopher Terpstra
Blue Steel offers about 3 inches (76 mm) of suspension travel
Christopher Terpstra
Blue Steel has foot pegs instead of pedals
Christopher Terpstra
Blue Steel took roughly 400 hours to build
Christopher Terpstra
Christopher Terpstra sizes up the original $10 donor bike
Christopher Terpstra
View gallery - 9 images

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 sizes up the original $10 donor bike
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,

A close look at the friction drive mechanism
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."

Blue Steel's one-sided front swingarm
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.

View gallery - 9 images
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4 comments
Expanded Viewpoint
No motor wires would have needed to be reversed, if the sprocket was just put on the left hand side of the frame instead of the right side. Duh. A guy I knew many years ago put a weed whacker engine on a little scooter, but he didn't listen to me and put the engine on backwards! Rather than reweld the brackets and do it like I told him to, he just threw everything in the trash can.
BlueOak
Totally impractical solutions to a problem that did not exist are the coolest thing. Kudos to this guy!
Thony
There doesn't seem to be anything left from original bike
AWF69
Thony, осталось - руль и резина :)