I especially like the thought about c of g on a motorcycle “needs to be ‘where it needs to be’”, not necessarily low as possible.

“Centralizing mass” should not be confused with lowering the mass too far.

Hello hoyt, I’m still around. Just to clarify: I’m a long-term bike guy who happens to work designing systems for cars.

On to the subject: it always entertains and frustrates me in equal measure when people expert in one discipline apply their “skills” blindly to an alternative task. Sure it’s good to see things from a different angle, but it makes no sense to apply concepts blindly before understanding the essential basics. Cars and motorcycles are dynamically very different. They work in different ways and have different requirements. Here are some initial thoughts:

Front end: the non-telescopic front end is technically superior, and good luck to them in pursuing it’s application. In the real world (i.e. road bikes) the barriers are cost, aesthetics and customer conservatism. Well done BMW. In racing the barrier is the risk of failure when departing from known solutions.

Centre of gravity: unlike a racing car where a low centre of gravity is almost always a good thing, the centre of gravity of a motorcycle needs to be “where it needs to be”. The C-o-G is determined jointly by the bike and the rider and hence can be dynamically altered and optimised by the rider according to dynamic circumstance (accel, decel, straight-ahead, left corner, right corner). The riding position here demonstrated seems to restrict the rider movement excessively, and hence will restrict the dynamic adjustment of the motorcycle.

Aerodynamics and rider position: as has been previously noted, top speed is not an issue. Most top road bikes can crack 170mph and racing bikes can touch 200 mph. Who needs / wants more? The crouch forced by this design is ergonomically difficult and something of a one-trick pony. Vision, manoeuvrability, hand and foot control will all be difficult.

Rider retention / reaction: when engaged in steering (…I guess everyone is familiar with the term counter-steer…) the force imparted to the steering is derived from and reacts against the mass of the rider’s torso. The rider’s torso is anchored to the bike by mass, gravity and lower-body grip. The lower body grip is mainly derived from friction against the seat and thigh / knee grip against the “petrol tank”. Hence the petrol tank area design is very important in consideration of rider retention and steering reaction. The design here demonstrated seems to completely ignore this fundamental requirement.

Radiator and exhaust position: seem to be an after-thought?

Swing-arm: to retain the required level of stiffness in the narrow “waist” section (between the riders feet) will be very, very costly. I agree with the previous comment about excessive frictional losses in the four-sprocket drive-train.

Stressed engine (i.e. suspension fitted directly to the engine): nice in theory but consider… a) heat transfer to suspension, fuel, and rider, b) engineering required to over-come thermal expansion at system joints, d) difficulty of changing the vehicle geometry once the engine castings are finalised, e) sub-assemblies still required to mount rider and fuel tank which probably means expensive carbon-fibre components, f) standard frame assemblies allow for relatively easy changes to geometry and re-package of mass for modification of dynamic characteristics, g) standard frame assemblies allow for relatively easy accident repair.

Overall: nice ideas from race car design blindly and inappropriately applied to motorcycle design.