The first time I saw Yamaha’s YZR-M1 MotoGP engine, I noticed the cam-chain tensioner was on the front, a dead giveaway the engine was backward rotating. Why would Yamaha do that? You have two big gyroscopes on a motorcycle that want to keep on spinning. When you steer the front wheel and try to lean the motorcycle over, those big gyros—the wheels, tires, rims, and brake discs—resist that with a precession force. So does the crankshaft. If we rotate the crank backward, its precession force will cancel some of the precession force from the wheels and the motorcycle will roll over more quickly. For a long time, Yamaha had the only reverse-rotating engine in MotoGP. Now others are doing it too.