In most motorcycle engines, your crankshaft will rotate in the same direction as your wheels — they’re linked by a chain and a transmission, after all. But MotoGP mills are different, their engines spin backwards relative to the wheels. Race teams aren’t traditionally in the habit of adding complexity for complexity’s sake, so there must be a reason for making the motors rotate in reverse, and it turns out the explanation is all pretty simple: It’s all to counterbalance the gyroscopic effect of the wheels.
Most motorcyclists or bicyclists know about the gryoscopic stabilizing effect of spinning wheels. It’s a reason our forms of two-wheeled transportation get more stable as they speed up — a spinning wheel wants to stay upright, which would make it very difficult for the attached vehicle to go tumbling. But this stability, this desire within the bike to stay upright, can impede the quick side-to-side cornering required on tight MotoGP tracks. By reversing the rotation of the engine, MotoGP engineers can use the movement of the crankshaft to cancel out some of the stability that comes from the wheels, and make their bikes a touch nimbler than our roadgoing machines.
It’s all physics
Riding a bike without that crankshaft stability isn’t just for the top tiers of MotoGP riders, though. You can actually do it right at home with any of the modern bevy of electric motorcycles currently zipping through American roads. Just today, I rode a Can-Am Pulse back-to-back with my own similarly-sized Suzuki GSX-8R, and the difference between the two is genuinely staggering. I won’t spoil a whole upcoming review, but electric motorcycles are nimble in a way that feels closer to bicycles than motorbikes.
Reverse-rotating crankshafts make MotoGP bikes that little bit faster to turn in, that slightest touch nimbler in the corners, and those minute differences can add up over the course of a race. These added levels of complexity are worth it for top-tier race teams, but they’re not necessary for the bikes you and I ride every day. If your daily happens to be electric, though, you’re a step closer than the rest of us.