4StrikeBike lets cyclists' arms in on the action
The 4StrikeBike concept would see riders pedaling with both their legs and arms, for a more complete workout and greater power
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.
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
Wouldn't it be easier to just drive the front wheel with the hand cranks.
I can't ride it anyway I have short arms and a long body with the handlebars that low I not able tilt my head high enough to see where I'm going.
I can see using an exercycle built like this, at least. No worries about weight, maneuvering while cranking arms, etc. in that case.
I would be interested to see data about kw generated to the ground compared to regular drive. Since there is force with movement on the handlebars in almost all riding situations, transferring(?multiplying) the torque applied to the foot bell crank, the arms are supplying "work". I suspect that it is a problem of lack of energy advantage, rather than difficulty in engineering a process to involve the arms in propulsion, that explains the lack of adoption of any of the leg+arm propulsion mechanisms.
Been doing this on my Schwinn Airdyne for more'n 25 years now.
I've built HPV's, hand-cycles and, yes, a handle-bar power attachment for bikes. There is a physiological limit to the concept. My handle-bar drive mechanism is efficeint and intuitive, but only renders benefits over brief bursts of power with gains of about 20 percent. Prolonged use leaves the rider sucking wind. It definitely has its place for attacking hills (especially while towing a kiddie trailer!!!) and for well-rounded workouts.
Good luck, my friends.
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