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. Video after the jump