BMW's wild concept trikes

Pushing the envelope in terms of 'personal mobility' – the new catchcry for ultra-compact vehicles – BMW is toying around with the idea of three-wheeled vehicles.

Two concepts, one named 'Simple' and the other 'Clever' (Ed: I prefer 'Ernie' and 'Bert') both vehicles are light (compared to cars), have three wheels, weather protection and room for a passenger to sit behind the rider/driver.

And like motorcycles, both concepts tilt through corners thanks to fancy suspension systems.

BMW Simple Concept
Powered by a 48hp combustion engine, it can accelerate from zero to 100km/h in "under 10 seconds" and has been designed to have minimal drag coefficient of just 0.18.

BMW reckons it would use just 2lt of fuel for every 100km travelled if it was paired with an electric motor. Not bad that.

Interestingly it "rides like a motorcycle" says BMW "and, beyond natural gravity and gyroscopic forces, requires no energy whatsoever to lean into a corner." It only uses hydraulic forces when the vehicle is stopped, to keep it upright.

Future mode of transport? Motorcycle buyers would probably shun it for being too expensive and car buyers might view it as a 'dangerous' motorcycle. Another potential issue with 'leaning' trikes is their low-speed manoeuvrability – tight U-turns could pose problems.

Either way, the Simple does look like a lot of fun, especially with a lean angle of around 45 degrees. Anyone who's ridden the Piaggio MP3 will probably keep an eye on proceedings.

BMW has not showed any intent to push such concepts from 'prototype' to 'production' status, but such concept vehicles are popping up more and more often. Nissan's upcoming Land Glider is an example.

BMW Clever Concept
The second concept design from the German bike and car company looks like something out of '80s sci-fi flick Tron. Boasting an angular design complete with gull-wing doors, the Clever is heavier and safer concept says BMW.

Powered by a 230cc single-cylinder combustion engine running on natural gas, BMW's second concept car weighs around 400kg. With 17hp channelled through a CVT transmission, it can accelerate from standstill to 60km/h in around seven seconds.

It features a pair of 1.7kg gas cylinders to hold the compressed natural gas (CNG) fuel that provide a range of some 200km and a top speed of about 100km/h. BMW claims it would therefore cost about one Euro ($A1.55) for the vehicle to travel 100km.

The Clever Concept also makes use of F1 technology (which is interesting considering BMW will exit F1 at the end of 2009) to improve occupant safety.

BMW explains: "As in a Formula One racing car, the main frame - weighing just over 60 kg - constitutes the survival cell, while the front wheel and steering ensure a deformation path of some 35cm to absorb sufficient energy in an impact."

In other words, it's much safer than a motorcycle in the advent of a smash. It also comes with special seat belts and is claimed to be 'secure' in a 56km/h frontal collision.

While the Simple and Clever concepts are certainly intriguing, and may see the light of day in the distant future – perhaps with revised designs – demand for such vehicles may be hard to find.