The word "exo" is of course an abbreviation of the word "exoskeleton" or "exoskeletal". Meaning "skeleton on the outside" Looking back in history it is likely that we need to go back to nature to discover when the term may have been used originally, probably with reference to animals or insects. Look at a grasshopper or scorpion and use your imagination and you may see a car. Maybe not but you may see a building, or did an architect look for inspiration in the direction of nature back in 1880? That was the year in which the first exoskeleton building was created, namely the conservatory at Schobrunn palace in Vienna.
Since then many buildings have been developed with exposed structures, some to make a statement and others to save space. A more recent well known building being the Gerkin in London built in 2004. Also worthy of note is the bridge in Ripoll Spain built in 1989. I wonder if car designers of the past also looked to nature for inspiration or possibly architecture? Maybe, back in 1955 the Cooper/Brabham featured a space frame chassis that looks very similar to the MEV approach of using curves and bends but in the case of the car in question it did have a body covering that delightful chassis so perhaps it was actually an endoskeleton (skeleton on the inside)
Moving forward we see engineering on show as a radical design step for Harley Davidson. Here is a quote from the design team who completed the creation of the VRSC in 2001.
"Part of the design brief for the V Rod was to create a frame that was a work of art as well as of engineering. This led to an external frame design with pipes bent into radical shapes using an innovative technique involving ultra high pressure water - the only way to get steel into the necessary form without creasing. It remains a key visual element of the bike." Of course exposed frames or chassis have been around for many years. Look back at the sand rails for early exo examples even if they were a little rudimentary. Maybe an earlier example of exo can be found under the somewhat weird looking Velorex produced from 1953-1971. It has curved tubes but thank fully that is where the similarity ends in relation to MEV's!
On the M1 near London a structure was erected many years ago for attaching adverts to. It has an inner meaning, this shape was apparently intended to resemble the "all seeing eye" of Christ but folded in half. There have been many EXO cars on the market including Atom, Deronda, Velocity, SDR, RCR to name a few. Some are more successful than others for various reasons. In 1996 the American LSV (Light Strike Vehicle) Chenoweth was first put in to use.. MEV have always been at the forefront by designing and developing several EXO vehicles in the last few years, here is a list. ROCKET ATOMIC TR1KE MEVABUSA EXOCET BATTMOBILE ECO-EXO E-TRIKE MISSILE EXOLEADER
An interesting coincidence is the comparison with the number of MEV "endo" designs, 10 of each in the same period, namely; TREK R2 R3 SONIC MEVSTER MONSTER CHARGER MEVX5 SUPERLIGHT REPLICAR
There have been a few design experiments that failed to gain support. Martin Aveyard carried out the work below which appears quite successful from certain angles although structurally flawed with it's curved diagonal "brace" tubes.