The Bergman 650 ABS is a dream machine with the exception of two minor deficiencies: It is at least 150 pounds overweight and it lacks sufficient engine assisted braking. Fix those two items and leave everything else alone for the remainder of the century. Side note: ABS has to be the greatest innovation applied to motorcycles since the abandonment of the suicide clutch. Krusty would have given his right leg for ABS on his CB350. First the fat problem. A 300 pound (dry) motorcycle, with an extra low c.g., that carries a payload of 300 pounds is very doable and will feel more like a moped than an XLH to the rider's delight. Replace the piston engine with a fuel efficient turboshaft engine, ganged planetary and CVT. Problem solved. Details: A 40 hp. turboshaft is no larger than an automobile starter motor and weighs no more, including the reduction gear. It is so simple and has so few parts, it makes you wonder why its taking so long to build it into motorbikes. Contrary to popular belief, a gas turbine is not a fuel hog if its run at a constant speed. The Chrysler Turbine Car was a gas hog because it was run with a throttle and hooked up to a TorqueFlite. A CVT is able to couple a constant speed engine to the rear wheel from zero to 100 mph. I calculate a 40 hp turboshaft will use no more than one gallon per hour in normal riding, about the same as the 650 twin used currently. The entire power train should weigh no more than 80 pounds, saving at least 100 pounds of weight. Another 50 pounds can be saved on the frame and accessories by using chrome moly, aluminum, titanium, and carbon fiber. Next the braking. At speeds below 30 mph, leave the braking system as is. But, above 30 mph, the CPU can do some wondrous things for this bike. The turboshaft normally runs at a modest 40,000 rpm. With a 10 or 20 pound flywheel on its mainshaft to add some rotational inertia, regenerative braking can be back-coupled through the CVT to boost this to 80,000 rpm. This extra stored energy under your seat can be controlled by the CPU and used again for acceleration. During the regenerative phase, the bike will feel exactly as a BSA 650 when the throttle is rolled off and that is reassuring. On very long downhills, or from repeated braking, the rpm will be limited to 80,000 and excess energy can be absorbed in the turboshaft compressor, bled off to the atmosphere, fuel cutoff and exhaust choked. The whole process will be seamless and the bike will slow down as if by magic. Regenerative braking has the beneficial effect of boosting economy; in stop and go traffic, the engine may never even light up. A very important point is to utilize CPU logic to control regeneration in conjunction with ABS and accelerometers to make it feel as though the engine is doing all the work, with no surges of extra power or sags of lost power. Smoothness is everything. No one is interested in coupling an 80000 rpm flywheel suddenly to the driving axle and exploding the tire in blue smoke. A few more embellishments are notable. A turboshaft is one of the cleanest engines around. Its exhaust is so benign, it can be routed to exit at the rider's feet so as to provide a gentle warm fresh air flow for comfort on those chilly morning rides. A turboshaft also needs no muffling at all and this saves weight and expense. All it emits is a subdued whine which riders will soon appreciate as the whine of power and prestige. A turboshaft may cost nominally more than a piston engine, but lets not forget the Burgman is not cheap; quality costs and conaseurs of the better things in life are all to happy to pay for it. Given an efficient aircleaner, good lubricants and an oil filter, this engine, unlike piston engines that wind up to 8000 rpm will last forever and a day. Expect no depreciation on a Bergman Turboshaft. Reciprocating engines are more than a hundred years old. They were great on the Constellation, the most beautiful airliner every created by Man, but they are obsolete in today's jet age. Yes, its possible to keep doctoring them up with turbos, fuel injection and eight valves, DOHC, and what else they can dream up, but its time to switch. They are a dead end and nothing better illustrates that than the unparalled transformation coming soon to your Honda dealer in the form of gas turbine power.
