We’ve been seeing a trend in bicycles that provide a drive train that utilizes arm as well as leg-power. The 4StrikeBike and the Raxibo Hand-Tret-Velo both offer hand cranks in addition to the typical pedal cranks.
Now Varibike looks to feature both a traditional drivetrain and a handlebar stem-mounted set of cranks that the rider turns with the arms. This power is transmitted from down to the main drivetrain via a rubber-sheathed chain. The advantage of this system is that it could allow riders to use just the arms, just the legs or both. This lets riders “vari” their workout.
httpv://youtu.be/dxsPBjiPyYE