Mobility engineering, done right

Posted on April 4, 2010


Most people don’t get why I’m building the DiffTrike. As the Cradle To Cradle guys put it, there’s “doing things right”, and then there’s “doing the right things“.

Mr. Amory Lovins and his Rocky Mountain Institute team have taken the time and effort to compile a very realistic overview of all that’s wrong with the cars we drive every day, and how to fix it. By “we” I’m referring to the American and European and Asian populations. But better than just bashing our addiction to Petroleum fueled vehicles, he puts forward the practical solutions to the over-spending problem – which right now in the automotive market means make lighter cars.

The smart thing to do, in terms of energy efficiency, is to start at the end of the supply chain: the consumer. The reason why is because each one percent reduction at the end of the energy distribution pipe will directly cause a several percent reduction along the whole chain (because of all the losses along the way), and so the consumer has the more “bang for buck” power.

This slide pretty much says it all about cars:

Lovins has shown us we could save 97% of the Oil we now use by making ultralight hybrid cars that run on E85 ethanol. We now know that ultralight cars can be cheaper to make and operate, much safer, and much more performant – and as a side benefit, they can make less pressure on the environment. What’s not to like? 🙂

On my part, I’d go even further and lose the internal combustion engine altogether. If a small 35kW hydrogen fuel cell is able to power a 900kg ultralight hybrid SUV (25.7 kg/kW), then there is no reason why 0.3kW human legs can’t power a 100kg commuter tricycle and load (333kg/kW) with the help of a smart hybrid-electric power train. See for yourself the pioneering work of Andreas Fuchs from Switzerland.

A German designer, Ulrich Sommer (also fond of recumbent trikes, apparently), is launching a standard-sized four seater that follows the Lovins mantra to the letter and employs light steels and extremely well integrated design into a 450kg Loremo available in Diesel, Gasoline, and Electric variants. This 3 liter car (78mpg) isn’t even a hybrid… its just a well designed regular car. Make it a hybrid, and get a whopping 156 mpg.

Yet another German creator, Stefan Gulas, is putting in the market something disruptively new: the e-Rockit human hybrid motorcycle. It’s got pedals like a bicycle, and it won’t budge unless you actually pedal, but it can take you to 80km/h speeds. It is beautiful in many ways, but in the end it is still a regular EV: you have to charge it on a power plug at the end of the day – that is the price to pay for such “super-human” sensations as taking a “naked” upright-sitting bike to high speeds with “just” your leg power: you can’t, not without some outside Lithium-Ion help. 🙂 But this is one genius implementation…

Alright; we’ve got weight, materials, aerodynamics, hybridization and electrification on our list of Right Things To Do. To which I add: size. Small is beautiful, and for several reasons.

Take the Tango EV, for example. Yes, it’s a kit car super toy, excessively powerful and noisy and ridiculously heavy, but the tandem seating concept is something so clever I never forgot. Putting 2 cars side by side on the road where only 1 car fits now is a genius idea; not only the roads instantly double their capacity, they also become more fluid – just like any one in bicycle-ridden Asia knows. And with that Nascar roll cage, it’s like riding a superbike, but in total safety. 🙂

I only recently discovered the French Lumeneo SMERA, which is like the Tango, but done the right way. 😉 It has 2 tandem seats, it tilts, and it is a fully Lithium powered EV that will get you across 150km with just 1 EUR of electric energy… and with the fun of a scooter. This is actually a production car, it can be bought right now in 2010 for around 25.000 EUR. A bit steep for my pocket, but considering it has the same range as the Nissan Leaf, one third of the weight, it costs 10.000 EUR less, and it tilts and cuts through traffic, I’d say it is a no-brainer choice. 😉

What’s more incredible about all these aspects is that they have been thought about and described in the technical literature for quite some time now. Take Robert Q. Riley’s great book “Alternative cars in the 21st century – A new personal transportation paradigm”, which defends the (heavier) Trike as a smarter replacement of the 4-wheeled car; and it’s been around since at least 1994…

This is a great book, be sure to a least peruse the pages at Amazon or a real life bookshop.

Putting all these aspects together, along with my personal views on electric serial hybrids, I came up with a requirements list for my next personal vehicle:

  1. very light frame, 1 or 1.5 or 2 seater tandem
  2. low and narrow (recumbent) aerodynamic body, preferably convertible
  3. serial hybrid-electric transmission, in-wheel motors
  4. 3-wheels only, no mechanical parts

Here’s a Lego frame concept I made a few months ago, when I first started the DiffTrike project out of a suggestion from John…

The model is obviously limited by the availability of the standardized Lego parts, and it only cares for the under frame, but for 20+10 EUR of spending, this turned out to be a really cool rapid prototype, and it does make people look twice. There are some secrets revealed in this Lego concept, but you’ll have to dig them out yourself for the time being. 😉

As I said before, the main innovative feature I want to implement in my Trike is the differential traction and steering system, which marries very well into an electric serial hybrid vehicle. I plan to make it distinctive by not having either a mechanical transmission or a mechanical steering; everything is “drive by wire”. This in turn opens up new possibilities, like the implementation of electronic stability programs. To my knowledge, this has never been done at the level of a human-powered light vehicle. 😉

So, to sum it up, I want to solve the problem of personal transportation in cities with a radically new and possibly cool Trike design, and to me this means rejecting the path most traveled of the heavy mechanical vehicle, and helping start an era of small yet elegant mobility solutions.

And now for a more philosophical thread of thought…

Most people today are still concerned with doing things right; domain specialization and optimization is the de facto standard in education and industry. I don’t like this current state of things. It makes it very difficult to talk about innovation and sustainability, because these are cross-domain preoccupations. In fact, innovation and sustainability themselves are almost seen as foreign objects, treated like some mysterious dark art or Utopian dream by most industrials and entrepreneurs.

I couldn’t disagree more. Whoever thinks like that belongs in a dungeon of the Dark Ages and should not be allowed access to more than bread and water until they repent. 🙂 This is quite evident to anyone who visits TED or a FabLab: We all have the power to dream and the power to make dreams come true; so why do most people settle with just chasing their next meal – even those who have their meals assured?! We need better integrated designs, designs that actually solve problems, and we need them now. Never mind if the industry is geared for bulky off-the-shelf components with more-or-less standard interfaces that result in inefficient and sometimes ineffective designs; let’s show them how to do it right. Let’s celebrate cross-domain integrated thinking.