The plywood velomobile design

The plywood velomobile is a true monocoque consruction of 1.5 mm aeroplane plywood (although no aircraft grade was used). Watch this vimeo for a short introduction.

This power point was presented on the 2012 velomobile summerlab (Link to the original keynote version). It gives some info about how I started, why plywood is an interesting material and detail pictures of the proto.

The rear wheel with Rohloff hub is mounted directly to the body. The front wheels are suspended with a Mc Pherson linkage.

Mc Person suspension in the plywood velomobile

To my knowledge Bart Verhees was the first to apply this suspension to the velomobile in his Alleweder. Interesting detail is the four bar linkage in the top view. The links (dashed lines in the picture) create a virtual point of rotation. In an automobile hollow wheels are used to allow the fusee axle to cross the tyre-road contact without to much camber. With a virtual point of rotation we can use bicycle style wheels (The four bar linkage McPherson was applied to automotive cars too). The PU foam spring is made of closed cell foam from BASF Elastogran. In this spring the functions of spring, damper, silent bloc and fusee bearing are integrated. I use Vaseline between the aluminium strut and the PU spring. I think one could argue that a McPherson suspension is not the best for a velomobile (See my post of december 2010 ).

This post describes the mass distribution of the prototype. I think we can loose some extra kilo grams. The McPherson struts have a wall strength of 2.5 to 5 mm now. Can be less. Maybe someone comes up with a nice deux chevaux like front wheel suspension. The plywood thickness could be reduced to 1 mm. There is an aluminium tube at the sheet edges on top and at the foot hole. These tubes measure 22x1.5 mm. The foot hole should be eliminated. The size of the opening at the top should be decreased and maybe the tube can be reduced to 20x1 mm.