Anyone know how to compare the parasitic loss of a counterbalance shaft vs a second rod on a thumper?
Uhmmmm maybe a DYNO?
But the Duc's advantage is NOT power, but how the power is put to the ground, which cannot be measured on a dyno. the only REAL way to measure it's effectiveness is on the race track, where it is head and shoulders above anything else out there. They don't make MORE POWER, they make the power more tractable, makes the bike easier to ride.
Sorry Mike. It's kinda obvious you don't appreciate how special the Ducati NCR motors were, but it was why a 85 hp 900SS could keep up with or beat a 140 hp Honda of the day, or why a 500cc two stroke can pace or beat a 1000cc four stroke. The magic of the Ducati twin is they have convinced the "L" twin bike it was a single
Let's try this: A crankshaft does not rotate at a constant speed, it speeds up as the piston goes down, maximum speed when the crank pin is at 90 degrees, slowest just before TDC and BDC, where it STOPS, eats a whole bunch of inertia, then slowly starts to speed up again. Every time it hits TDC or BDC it stops the tire and the tire deforms and loses traction and the tire slides a bit. On a 4 stroke I4 this happens twice for every crankshaft rotation, a triple 1.5 times, a twin once and a single every other crankshaft rotation.
A counterbalance shaft stores inertia, it pulls inertia off the crank at a more or less constant rate and throws that inertia when the crank pin is at 90 degrees, and the crank reacts like it got another power pulse, it BANG speeds up, like if it had another piston firing 90 degrees opposed.
The Super mono pulls inertia off the crank, but in a MUCH smoother pull. When the pin is at 10 degrees ATDC the fake rod is pulling next to nothing, and it ramps up to pulling it's maximum at 90 degrees, then tapering off to next to nothing at just before BDC. The "fake" rod is pulling inertia at a rate that is 90 degrees opposed to the real rod. That rate of inertia goes up and down as the crank rotates, It smooths out the power pulse, being easier on the tire.
If you were to graph the power at the output shaft, the line would be very "peaky". There is no single motor that has a smoother power/time graph. A single with a counter balance would have exactly the same peaky line as a twin. A super mono line looks more like a sine wave.
The "new" 270 degree twins try to do the same thing BUT use another piston. I put NEW in quotes cuz there's nothing new about this. We've been "phasing" twins as long as I can remember and this is what a "big bang" motor is all about. The R1 "big bang" motor came about because there were a couple of guys racing BSB that "phased" their R1s and were spanking the field... so they banned the motors. NEXT year Yamaha had a "big bang" R1
TL/DR: A DUC super mono will spin/slide the tire less on corner entry and exit, compared to any other design we have so far, all things being equal
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