Is the in-line four cylinder motor about to become the most developed engine for performance motorcycles? BMW’s choice for this platform and Yamaha’s development of their cross-plane crankshaft engine are two obvious points. What if either of those manufacturers combine their strategies with something similar to the Horex’s staggered piston arrangement? The Horex 6 cylinder engine head cover is under 17 inches across. Would a similar reduction be achieved with a staggered four, resulting in an engine more narrow than a triple?
How about mass centralization? Bott Power’s Moto2 bike has tremendous mass centralization (see photo). Its gas tank is primarily underneath the rider’s mass when the rider holds the clip-ons. This is arguably more centralized than Buell’s approach. The torque advantage of the cross-plane crankshaft, the staggered piston arrangement of the Horex, and the mass centralization potential of an in-line configuration could be difficult to beat on the street and on the track.
The twin cylinder engine could be developed to the point where manufacturers begin to dwindle the amount of chassis used by strengthening the heads as structural connection points, but at this time, that seems to be very costly (e.g. Ducati’s patent for a “frameless” motorcyle using carbon fiber sub frames attached to the engine). What other areas can the development of the sporting twin be taken?