Guest Blog: Mat Oxley - The Yamaha MotoGP bike you never knew existed is delighted to feature the work of iconic MotoGP writer Mat Oxley. Oxley is a former racer, TT winner and highly respected author of biographies of world champions Mick Doohan and Valentino Rossi, and currently writes for Motor Sport Magazine, where he is MotoGP correspondent. We are featuring sections from Oxley's blogs, which are posted in full on the Motor Sport Magazine website.

The Yamaha MotoGP bike you never knew existed

Almost two decades ago Yamaha built a single-crank new YZR500 to beat Honda and Valentino Rossi to the final 500cc title. The bike remained a secret, until now…

Yamaha has won plenty of MotoGP titles since the four-strokes arrived 16 years ago, but the factory had a miserable time in the final years of the 500cc World Championship. Yamaha was defeated nine years in a row, mostly by Honda, which is why its engineers built an all-new bike for the final 2001 season of 500s, when Honda and Valentino Rossi would be their greatest rivals.

This bike was tested in Europe in the summer of 2000 by Marlboro Yamaha riders Max Biaggi and Carlos Checa, less than 18 months before the final 500 GP, but never raced. And somehow, Yamaha managed to keep the project secret. Until now.

Yamaha engineers were so desperate to win again that they cribbed the bike’s most vital performance feature from Honda’s NSR500, winner of seven of the last nine 500 championships.

The battle for supremacy between Yamaha and Honda V4s had been the big deal in the premier class since the mid-1980s. The two machines were similar, but for one crucial difference: the NSR500 used a single crankshaft, while Yamaha’s YZ500 used two contra-rotating cranks.

During the first decade of this technology duel, Yamaha’s twin-crank engine seemed the better solution. The two cranks rotated in opposite directions, cancelling out torque reaction and crankshaft inertia for friendlier handling and power delivery. So much so, that Honda built a twin-crank engine in the late 1980s but never raced it because HRC hated copying rivals. After all, a twin-crank NSR would’ve been like Yamaha building a V4 MotoGP bike for 2018, or Ducati building an inline-four.

By the late 1990s, it was Yamaha doing the copying. Biaggi and Checa, who had both joined from Honda in 1999, became convinced they needed a single-crank YZR500 if they were to win the historic final 500cc crown.

Read the rest of Mat Oxley's blog on the Motor Sport Magazine website.


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Comments it even possible to have TWO crankshafts? I once read about Aprilia's 250 having two of them, but I thought it was a misprint. Educate me, David!