A trio of 451mm wheels and several piles of folded sheet metal and machined parts have accumulated in piles around the place as I anxiously await the frame to arrive. I’ve been hesitant to release too many details as the design evolved since it seemed to only encourage more confusion than clarity (have you ever tried to explain what a velomobile is to the unfamiliar in the first place?) but since the prototype is being built up this is a good time for a summary.
But first, here’s a picture of the chassis CAD model.
The structure is made from a bamboo plywood/balsa core sandwich structure which, once hot-press laminated, is cut out by a CNC router. No tooling, no welding, no coping of strangely angled tubes.
All three wheels are independently suspended, which sounds like a great idea until it comes time to buy three mountain bike shocks at retail price that, pound for pound, must be more expensive than Formula 1 Konis. They don’t cost nearly that much to OEMs, which I’ll take advantage of next round.
One of the features I’m most proud of is the tilting mechanism. The front shocks are connected to a linkage that allows the rider to control the tilt of the vehicle independently of steering angle. Steering is reacted trhough the rear wheel, freeing up room at the front of the vehicle and allowing a much tighter turning circle than if the front wheels turned.
Since the electronic transmission idea got shelved (a story for another time) I looked for a system that would allow a wide speed range, could be shifted at rest and had enough speeds that the desired cadence could be dialed in perfectly. The closest mechanical analog turned out to be a NuVinci CVT combined with a Shlumpf MountainDrive, which give an overall gear range of more than 6.
In other news, Smokey the inverter has been nursed back to health and will be heading stateside in only a few days!
