Our story the other day about the Ev-0-rr electric motorcycle designed by Mark Wells, mentions the composite monocoque chassis. One of the comments asks:
This implies those may not be fairings, but are in fact the chassis. Any confirmation on this? What prevents a ICE motorcycle from doing the same? I know there are perimeter frames, so it doesn’t seem impossible.
Mark Wells, was kind enough to leave a lengthy comment in which he says:
The carbon-fibre monocoque chassis that the Ev0-rr will run is an evolution of the planned Lotus superbike, which was seriously considered by the Norfolk firm in the late 1990s, designed by legendary racer and engineer Peter Williams. The bodywork for the Williams-designed motorcycle is made from two parts of carbon fibre, which clamp together around the engine. Once they are bolted together they form a stiff shell, providing all the rigidity the motorcycle needs. Based around an eggshell design, it is split vertically down the middle with an aluminium section to hang the electric motors and batteries from.
Think about the possibilities of using this method of construction. Although we are used to seeing frames providing the strength in motorcycles, sometimes in conjunction with the engine itself for mounting various pieces, the automotive world has long used the monocoque chassis to great advantage. Now 2 wheelers, instead of using fairings that simply cover the sometimes untidy mechanical components, can use them to serve both exterior design functions and as chassis, too.
However, with different components to work with, electric motorcycles are under less constraint in the design process and sometimes, designers try to emphasize the difference. What happens, though, is traditional motorcyclists are less enthusiastic and sometimes put off. As Mark says:
We really feel the trick with zero emissions vehicles, at this stage in their development, is to give motorcyclists (and petrol heads in general) what they know and more importantly love. This is why the illustrations we have made for the EV-0RR are very ‘MotoGP’ in proportion and stance.
In a way, by designing an alternative power motorcycle in such a manner that design doesn’t become an issue itself, attention can return to the actual powertrain and whether or not it works as intended, winning converts, one motorcyclist at a time.
Whether the monocoque chassis becomes more common in motorcycle design will depend on other factors beyond function, cost will be a big issue, ease of working with the material and the different knowledge necessary to form a strong and safe chassis among others. All will come in time, but efforts like the Ev-0 rr show us it’s possible.
There will always be a strong attraction to exposed metal and mechanical function but this monocoque composite construction represents some very interesting design and engineering. I like it.