Velomobile Kit? or Retro-fit?

With the Veloci Velomobile method of body construction it will possible to scale it to fit a wide range of different recumbent trike chassis.

This is already been done by other manufacturers with the Borealis velomobile as well as the Ocean Challenger .These are both fine examples of fitting bodyshells to existing recumbent trikes. The drawback is that they are quite heavy (32-36kg) and still relatively expensive.

Veloci Velomobile would weigh in at 20-23kg depending on the trike used as the chassis. This would be a great option for someone who already owns a trike and wants to have a cost effective way of converting their recumbent trike to a velomobile. The estimated cost for a retrofit to an existing trike chassis would be $US = 1000 or Euro = 780.

This is only one option as a custom designed chassis would have less compromises and maybe even be lighter! I have built three recumbent trikes - two with rear suspension, with the lightest being 13.5kg and the others 15-17kg so in theory Veloci Velomobile could be as light as 18-20kg complete!

Velomobile safety and drag co-efficient

There has been a few cases of late of cyclist being hit by cars with major injuries or death being the result. I still think it prudent that some sort of passive safety is designed into Veloci Velomobile. I really like the construction method used on the eco-car TREV It is lightweight, reasonably easy to construct but very strong and with the foam as a core would have some energy absorbing capacity.
For Veloci Velomobile I will design a semi-monocoque with the monocoque being where the rider sits while the suspensions and crank boom are attached to the monocoque. I believe this would be the best approach to keeping it lightweight and having some crash/impact protection.

In addition to the crash protection of Veloci Velomobile I have been redesigning the bodyshell to make it a little more slippery and make the forward vision for the rider a lot better. I now have the Cd figure down to 0.20 thus the CdA= 0.45 x 0.20 = 0.09 which is really good and better than the Quest velomobile now. 

Veloci Velomobile drag co-efficient now 0.20

June 2013 Veloci Velomobile latest shape rendering

Velomobile excellence!

"Any intelligent fool can make things bigger and more complex... It takes a touch of genius --- and a lot of courage to move in the opposite direction."

 - Albert Einstein

A great quote from a great mind.

My goal for Veloci Velomobile is to make a velomobile which is practical, functional but yet elegant in it's design. Having ridden a couple of other 'hard shell' monocoque velomobiles (AeroRider & a home build fully enclosed similar to the AeroRider) I found both these machines too heavy and being fully enclosed too claustraphobic. To keep thing lightweight I will be using a space-framed chassis with suspension on all wheels and mounting a non-load bearing lightweight shell made of coroplast/corflute.

I really like John Tetz's work with velomobiles and he has produced a one-off velomobile that is lightweight, fast & practical.

Velo-Excellence! - John Tetz Foamshell Velomobile

CdA Calculations & Visualisations

Using the virtual windtunnel it was calculated that the shape of veloci velomobile has a drag co-efficient of 0.27 using this information to calculate the cdA which is cd x A (frontal area) = cdA.
Knowing that the frontal area is 0.45m2 X 0.27 = 0.1215 cdA which I believe to be pretty slippery. The Quest velomobile has a cdA of 0.09 but this is not confirmed as accurate or in what configuration. So for a velombile that will cost a quarter of what a Quest will be nearly as aerodynamically efficient. It was also interesting to note that a lowracer such as the M5 has a cdA of 0.14 which is  very good and is due to the very small frontal area and the tailbox, the great thing with these bikes is that they are so light (claimed 8.5kg) . This has made me think about the suitability/practicality of velomobiles as a lowracer can get pretty close aerodynamically and weigh a lot less than a velomobile. This is why I believe a lightweight velomobile (under 20kg) would be very effective as long as its cdA is low (0.10-0.08 would be optimal).

CFD that velomobile - virtual windtunnel

Veloci velomobile in the virtual windtunnel

After getting the basic shape and dimensions it was time to see if the body shell was aerodynamic! After all what is the point of putting a body shell on a human powered vehicle if it does not make it more efficient? The added weight of a body shell needs to be offset by the improved aerodynamics to make it worthwhile.The information gathered from using  a virtual wind tunnel has already led to me 'tweaking' the design to let it slip through the atmosphere with ease.

Velo Chassis / Test Mule

Now that I have finalised the body shape/dimensions I need to build a chassis for everything to attach to! I thought about using an commercially available tadpole trike but there are too many compromises. So I designed my own!As this is experimental I wanted to design it so changes can be made easily. I decided to make it out of 9mm ply as a semi-monocoque design with the seat being part of the load bearing structure. I like working with wood so this construction technique suits me. The pictured design is the chassis backbone and seat which still needs the boom, front suspension arms and rear swingarm. Pictured chassis weighs 3kg. I estimate the rolling chassis will weigh 15kg plus another 6-7 for the body shell giving my target weight for this velomobile of 20-22kg.

Modelling in 3D - Velomobile Crash protection?

Modelling in the 3D environment is quite easy. The basic steps are to create polygons, lay out basic dimensions and then modify the polygons to get a rough shape. From this rough shape filters can be applied to smooth the shape.

Another consideration when designing this velomobile is the matter of crash protection! Unfortunately there are drivers of automobiles who are not attentive enough when it comes to their driving. I have seen a few collisions (and been involved in two myself) while on a bicycle. All these collisions involved the car driver not being carefull or considerate to the rider.

So how do we make bicycling safer? There is no easy answer. How do we make velomobiles safer? Well my thoughts are to have some sort of roll over protection and in the case of Veloci velo to have side intrusion bars fitted to the chassis. These would only have to be strong enough to not bend when hit by a force equal to the mass of the velomobile and it's rider.

I really like Trisleds Rotovelo which is a rotary moulded monocoque which is strong (but a little heavy). Maybe the answer is not to get hit by becoming more visable eg. bright colours for the bodyshell and using flashing LED's even when riding in daylight. Some riders use flags, I like the idea of a aero mast which would be painted in a fluro safety colour and also have a flashing LED's on top for 360 degree visability.