Contortionist: cleverly designed full-size folding bike


August 10, 2009

The Contortionist folding bike with its unique styling and chainless drive

The Contortionist folding bike with its unique styling and chainless drive

Image Gallery (4 images)

Folding bikes make a lot of sense for the urban commuter, and at Gizmag we've been busy keeping up with a steady flow of impressive designs that look to marry the convenience of a small folded footprint with the usability of a full-size bike. Some of our favorites include the Switch Commuter Bike, Airnimal, Mercedes-Benz folding bike, IF MODE and Onyerbike, and we can add the Contortionist prototype from 24-year-old UK inventor Dominic Hargreaves to this list of ‘shrinking’ bikes.

The Contortionist is 24-year-old Dominic Hargreaves’ entry in the UK sector’s James Dyson Awards, an international design award that “celebrates, encourages and inspires the next generation of design engineers.” So far he’s made the shortlist.

“The brief I set myself was to create a folding bike where all the parts fit in between the circumference of its 26-inch wheels when it is folded up. Once folded, the bike cannot fold back on itsself while riding. The wheels rotate when folded up so the folded package can be wheeled along rather having to be carried.”

The result is a bike that folds down to a size similar to that of a collapsible wheelchair and can be dragged along behind, as the video demonstrates.

What’s more, the bike doesn’t have a chain that can foul or leave grease on clothes or skin. Rather, this prototype will feature an internal hydraulic system that uses oil pumped through tubes in the frame to power the back wheel. And being a full-size bike (26-inch wheels) the ride is designed to feel similar to a regular bike. Hargreaves says it can even be taken off-road, hence its mountain bike tires and aluminum frame.

To help it fold the front and back wheels are slightly offset which Hargreaves says doesn’t affect the ride of the bike.

The inspiration was that the current range of folding bikes on the market seemed to be too much of a compromise, or just didn't fold small enough for day-to-day use on public transport.

Hargreaves says he has been approached by strangers who tell him how good the unfolded bike looks and are surprised when they find out he designed it himself. He says they’re even more surprised when he shows them how quickly and small it folds down.


The video doesn't really show much footage of the bicycle being ridden, I can't see the design being at all stable or nice to ride. Ok so ja it folds up, in a very clever way, but what is one suppose to do with it folded up? I can see it taking up just as much space as a normal bicycle.


In my experience on a folding bike there not very stable due to not having the middle bar. In comparison this does look very stable, my major worry would be the one prong folding forks ???

James Tereszczak

In general there is not much that can beat a standard diiamond frame when it comes to rigidity, stiffness and strength. I think this frame will be suffering from too much softness and looseness in the hinges, not that it will be unrideable, but a bit of softness is what I would expect. The drive system is also a big "if and how", since a hydraulic drive system is almost inevitably going to have too low efficiency to be favoured by cyclists. I did notice that on the video there was very little real pedalling, so it is possible that this is only a show version without a fully working drive system..

But I really did like the concept and hope to see something like this on the streets someday


How efficient is the oil drive system? I would think you would see this in autos by now if it was efficient.

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