Changeable Cycle

By Sara Ferris

Imagine cycling 50 miles, stopping at a convenience store to refuel, and having no way to get inside. This frustrating scenario prompted a trio of handcyclists—–whose machines were too big to get into the store and whose legs couldn’t carry them—to invent their own solution: the morphing handcycle.

A handcycle is a three-wheeled vehicle powered by the arms. In lowrider position, the morphing handcycle takes on a stable and aerodynamic profile. Users can ride it as far as any bicycle at roughly the same speed. When it morphs into high-rider position, it gains a wheelchair’s agility for navigating doorways and aisles. It also raises the rider to eye level with standing persons.

The Morphing Handcycle easily coverts to a more vertical configuration for navigating tightspaces.

Rory McCarthy, Bill Warner, and Graham Butler used SolidWorks (Concord, MA) to design the morphing handcycle as a project for McCarthy and Warner’s nonprofit Move With Freedom organization (Cambridge, MA). McCarthy is a longtime electrical engineering designer, and Warner is founder of digital media creation tools company Avid Technology.

“Any CAD software lets you design and assemble parts,” said McCarthy, who has cycled the globe on a handcycle. “SolidWorks software, however, made a big impact on our design by letting us experience the assembly in motion. Graham,  our product designer and SolidWorks expert, was able to turn my high-level designs into detailed virtual prototypes. This was critical in conceiving and refining the four-bar linkage and the crankset/steering assembly, which needs to turn smoothly in both low- and high-riding positions. As a result, we’ve got a highly functioning physical prototype ready for user feedback.”

The morphing handcycle uses no electronics. To morph into high-riding position, the rider sets the brake and rolls the rear wheels forward, as with a wheelchair. The 24-speed cycle employs twin mechanical gas shocks, specified for the rider’s weight, that assist in the lift. That allows the user to switch to high-riding mode with single-hand force. Other components are standard bike parts.

McCarthy embraced SolidWorks from the onset of the project two years ago. “I’m a longtime AutoCAD user, yet SolidWorks immediately proved to be a great tool and a more intuitive and logical way of designing,” he says. “When it’s time to build, most of the questions have already been answered. We took care of the trial and error on the screen.”

The morphing handcycle embodies Move With Freedom’s commitment to easy and natural mobility for all. Rather than commercially protect it with patents, the company intends to donate the finished design to the public domain so that others can customize it for their own needs. Move With Freedom’s next project is a morphing wheelchair, which would make it easy for users to surmount a curb without risking a backflip.

“We’ve seen many instances where SolidWorks improves business performance,”  said Rainer Gawlick, vice president of worldwide marketing. “It’s inspiring in this case to see improved human performance and a direct positive impact on quality of life.”

Click here to listen to a podcast interview about the Morphing Handcycle.

Click here to see Rory McCarthy demonstrate the Morphing Handcycle.

Sources: Press materials received from the company and additional information gleaned from the company’s website.