First stunning stripdown pictures of Yamaha’s M1

SOME said it was going to be nothing more than a R1 engine bolted into a 500 GP chassis. But these first stripdown shots of Yamaha’s M1 four-stroke prove that couldn’t be further from the truth.

Exact details of the M1 are still sketchy, with Yamaha still only saying the bike is under the 990cc capacity limit and weighs a little over the 145kg (319lb) limit for the engine configuration.

Power output is fractionally up on the current YZR500 GP bike, making around 200bhp at 15,000 rpm, but according to the men involved in the project the M1 has a higher torque output and a greater spread of power.

It can clearly be seen from the pictures that the main spars of the Deltabox-type aluminium frame are a similar configuration to the YZR ridden by Max Biaggi and Noriyuki Haga in GPs.

But the M1 spar section is much beefier to cope with the huge forces that over 200bhp will place on the chassis.

The suspension and brakes are also closely related to GPs, with forks that appear identical to those on the YZR, and massive, radially- mounted Brembo calipers gripping carbon discs.

What still remains a mystery is the cone-shaped black structure on the rear hugger. A 2D datalogging sensor can clearly be seen attached to it, but what purpose it serves has not yet been revealed.

We do know that the M1 uses a familiar trait of five-valve heads, a six-speed cassette-type gearbox and a dry clutch.

These pictures reveal exactly how compact the new engine is – it makes road-going motors like the R1’s 998cc four look massive. It’s dwarfed by the huge radiator needed to shed the enormous amount of heat it generates, and even the carbon-fibre airbox looks almost as big as the engine it feeds.

More details of the M1 are expected to be released later this week.