Bicycle or Quadricycle: Deploying the Roots of El Arbol

The 6' wide 'roots' of El Arbol stabilize it at low speeds, when stopping, for use as a 2-person Pedal Power generator, and for getting on and off. The mechanism that deploys that roots is a lever on the head tube. It yanks a Porsche transmission cable through a pulley and then down through fat cable housing to the underside of the rig, where it splits and pulls the two roots out. Concealed springs in the rear swingarm handle the retraction when the lever is released.

The lever is foot-actuated, meaning the both hands of the rider can stay on the grips and brakes for safety. The roots are anchored using headset bearings, designed for the types of side loading that happens when deploying them on uneven terrain. See photos of the welding and metalwork: http://www.flickr.com/photos/rockthebike/sets/72157603775437749/with/5259114595/ The wheels are 7" pneumatic razor scooter wheels.

Previous to this design, designers of tall bikes faced the basic challenge of how to stop and start safely. California Vehicle Code Section 21201 specifically prohibits tall bikes, saying "No person shall operate upon a highway a bicycle that is of a size that prevents the operator from safely stopping the bicycle, supporting it in an upright position with at least one foot on the ground, and restarting it in a safe manner."

Many owners of tall bikes would counter by saying they can stop safely by jumping off to the side. To restart in a safe manner, they run alongside the rig and hop up when they have a little momentum.

With the roots of El Arbol, there is no need to put your foot down or hop off. The stops and starts shown in this video are safe and effective.

Category:

Science & Technology

Tags:

• bicycle design
• tall bike
• quadricycle

[cellojoe]

yo! i love the new framing of the rest of the tree!