You might not have noticed at first glance, but the handlebars of the 4 Strike Bike are actually a second set of pedals. Unexpected, isn't it? Lex van Stekelenburg came up with the concept as a means to assist with posture and strengthen the muscles of the back. This idea was further developed by TSG Essempio, who turned it into the sleek and intriguing piece of equipment that you see here.
The chain of the 4StrikeBike leads from the foot pedal gears, up the frame of the bicycle and towards the front. It winds around another gear that connects to the rotating hand pedals, enabling the work to be distributed between the legs and the arms. The handlebars of the 4 Strike Bike can also be locked in place if you'd like to ride it normally.