The case against Carbon Fiber!

https://www.outsideonline.com/2261721/dirty-secret-hiding-your-high-end-mountain-bike?utm_content=buffer12110&utm_medium=social&utm_source=twitter&utm_campaign=tweet

Open wheel Velomobile

On my previous post "F1 inspiration" I tested a open wheel design which surprised me with it's aero efficiency. I decided to model this up a bit more in detail with some of the renders below.

What I really like about this design is its simplicity, ease of construction and ingress and egress would be very much easier than a wheels in design.

I can see many benefits especially I think this type of velomobile design would be more accepted by the general public as still being a "bicycle".

F1 inspiration

I have been looking at single seat race cars for inspiration and although F1 cars have really bad CdA figures that is in part due for the need to have huge downforce and air intakes to cool a high output power plant.
The F1 tub by itself has to protect the driver but also allow the smooth flow of air to the wings, foils and intakes. If we take away these downforce/cooling aids (by the way they are not aerodynamic aids!) we are left with the tub/driver pod.
I quickly modelled up a velomobile with similar design to a F1 tub and put it through the CFD. It made for some astonishing results.
The frontal area calculated out to be 0.32m2 and the Cd was 0.28! put these two together and I got a CdA of just 0.0896 !!!

Although this figure is higher than my older design which had a CdA of 0.07. It really is an interesting comparison and with this "Open Wheel" design it could be made a lot lighter and easier to produce and also have a smaller turning circle. This could be a great design for a practical everyday velomobile.

Simplify and add lightness

Colin Chapman's quote "Simplify and add lightness" should be the catch-cry of anyone designing a velomobile or human powered vehicle. One of my favourite designs which has been designed along this mantra is Bob Stuarts Car-Cycle X-4 https://microship.com/bob-stuart/

This is a fine example of integration of parts to make a simpler vehicle. The use of different materials such as fibreglass for the chassis and coroplast for the body is using the correct material for the job. The fibreglass chassis incorporated the hinges for suspension so in fact the chassis IS the suspension. The coroplast body is tough and resilient to bumps and knocks as well as being lightweight.

Another consideration I see in this design is the cost factor with no real "exotic" materials used.
Too often Carbon fiber is seen as a miracle material and used inappropriately or used in a way that does not utilise its specific properties (i.e.. stiffness with low weight). Read about this wonderful vehicle from the link above.

Full size mock-up of Velomobile chassis

Mockup of velomobile semi-monocoque to test size and entry/exit. Will have to tweak the design a little. Very easy to get into but a little tight around the shoulders. Will revise.

Velocivelo semi-monocoque ©2017

Practical City Velomobile

I see a need for a velomobile that can integrate well with city traffic. This would mean a higher seat height and room for a child and/or groceries in the back. Again the design must be lightweight and aerodynamic. I really like the Mochet Velocars of the 20's, 30's and 40's . Below is what I see as a possibility.

Length = 2400mm   Width = 1000mm   Height = 1050mm  Weight = 45kg

Wheels out velomobile

Here is a render with exposed wheels on Veloci Velomobile. Advantages of this design is the ability of  a tighter turning circle and ease of changing a tyre. I like the look of such velomobiles with the only downside being loss of aerodynamic efficiency (this would be quite small).