4StrikeBike lets cyclists' arms in on the action
By Ben Coxworth
April 29, 2013
Although cycling is a great form of cardiovascular and lower-body exercise, it doesn’t do a whole lot for the upper body. Over the years, various arm-and-leg-powered bikes have been developed, such as the Raxibo. Now, however, retired surgeon Lex van Stekelenburg is hoping to get his own such vehicle into production, in the form of the 4StrikeBike.
Van Stekelenburg came up with the idea for the 4StrikeBike after years of standing bent over in an operating room left him with back and shoulder problems. Over the course of five years, he and a number of volunteers tried out several prototypes. He recently got in touch with Dutch design firm TSG Essempio, in hopes of getting his concept polished up and ready for production.
The new 4StrikeBike concept has a conventional leg-powered drivetrain, although it also has a set of arm-powered pedals/grips in place of regular handlebars. These are turned in circles as is done with a crankset – the Raxibo, by contrast, has the rider “rowing” both arms forward and backward in unison.
A belt drive runs from the 4StrikeBike’s handlebars down to the bottom bracket, where the rider’s arm input augments the power from their legs. A freewheel mechanism allows both drivetrains to be used simultaneously, or either one to be used on its own.
The handlebars are reportedly able to turn from side to side without interfering with the belt drive, plus an integrated “steering stabilizing mechanism” helps keep the hand-pedaling movement from sending the bike off the road. Additionally, both of the hand pedals can be locked into their highest position, allowing for a more stable stance while riding using leg power alone.
TSG Essempio product designer Jan Willem Zuyderduyn told us that at the present time, his company doesn’t have an estimated price or weight for the commercial version of the bike. Industrial partners are currently being sought, and can contact Lex van Stekelenburg via the link below.