Put this StepTwin bike under the category of wacky bicycle inventions that are oddly entertaining to watch, maybe even something you’d actually want to try – if only to see what it feels like to ride. But what you end up with is a small wheel folding bike with a unique method of propulsion that you stomp down on like a StairMaster!
StepTwin folding bike with alternative pedaling motion
The developers of the StepTwin call it the first ‘bionic’ folding bike. I’m not sure really how it augments or enhances the body of the rider and more than a regular bike would to get the bionic label, but it certainly is different from most bikes we come across in our daily life. Much different from other folders with its independently two-sided drivetrain, and much more compact than other stepper bikes we’ve seen (and jeered at.)
StepTwin bionic folding bike, in the details – How does it work?
Basically the idea is to stomp down with either foot, and a lever attached independently to each crank arm transfers power to a chain that drives the rear wheel and then automatically comes back up when you unweight the pedal.
Drivetrains exist on both sides, and you can pedal/stomp with any combination or right and/or left foot inputs, even at different cadences. All that works thanks to a special rear hub with independent freewheels & a replaceable track cog on each, and the unique multi-arm cranks.
In fact, there are actually five speeds available through a shifter that alters the leverage ratio of the crank lever, and you can adjust the two sides separately – ie. you can pedal in an easier gear with one leg & harder gear for the other. The rationale is that this contraption can be useful for people recovering from injury, or even for more specialized training.
The Step Twin bike can be ridden with or without a seatpost – they say “you sit, you walk, you ride.” And of course it is a folding bike, so things like the seatpost & handle bar are easily adjustable, and it collapses down tool-free in less than half a minute for transit. The bikes come in one size only, but the telescoping design is said to fit a huge rider size range – for people from 130-210cm tall (4’3″ – 6’10”).
There’s no denying that this thing is wild-looking. And the Dutch developer can be a bit hyperbolic talking about the StepTwin: “The ultimate bike for ALL your needs!” But is certainly is interesting.
StepTwin bionic folding bike – Pricing & crowdfunded Availability
The StepTwin is currently being offered as a pre-order through a flexible goal crowdfunding campaign on IndieGoGo (remember, that means they get your money and promise to deliver whether or not they meet their funding target.)
The one-speed StepTwin Sport with a hi-ten steel frame (still dual-sided drivetrain but without the adjustable gearing) has an early backer’s price of just $150 and a 10.6kg (23.3lb) claimed weight.
The $190 StepTwin Street sticks with a hi-ten frameset, but upgrades to the independent 5-speed drivetrain for $190 and a claimed 9.2kg (20.2lb) weight. Opt for the StepTwin City with aluminum frame & 5-speed for $250 7.8kg (17.2lb).
And yes, there is also a StepTwin Country that actually gets a titanium frameset & the 5-speed setup for $380 and a claimed weight of 7kg (15.4lb). StepTwin has already finalized the drivetrain setup & manufacture, and is moving into finalized production over the winter. They expect delivery of complete bikes to IndieGoGo backers to ship out in March & April of 2019, with an online progress tracker available to backers to see live updates of their bike’s progress.