In 1923, two Italian engineers, Piero Remor and Carlo Gianini, designed an inline four-cylinder motorcycle engine that was mounted transversely. It was an important moment, for from that beginning have descended all of today’s inline-four motorcycle engines. Technical Editor Kevin Cameron and Editor-in-Chief Mark Hoyer talk about the origins of the modern in-line four sportbike from Rondine to Gilera to today. Illustration by Jim Hatch/Hatch Illustration.