Instead of compressing a spring to push the valve open and then waiting for the spring to return the valve to its starting position, a desmo rocker arm that opens the valve works in conjunction with a forked counterpart that rides against an inverse cam profile to pull the valve back against the seat. There’s no energy wasted compressing a stiff spring, and there’s no need to wait for the spring to close the valve. In fact, according to Ducati CEO Claudio Domenicali, that’s the desmo’s main advantage. “It’s not only the resistance,” he said when asked about desmo technology. “The way you can open the valve is far more aggressive. You are more efficient in terms of fluid dynamics.” More aggressive cam profiles result in more gases making their way into and out of the combustion chamber with each revolution, and more mixture means more power from the engine.