Introduction
Three years after making its racing debut Yamaha’s YZR-M1 clinched the riders’ title at the hands of multiple MotoGP World Champion Valentino Rossi. In what has been considered to be the most significant and memorable victory in the championship’s illustrious history, 2004 was a culmination of the gifted Italian’s superhuman ability and the technical ingenuity of Yamaha’s Technology Development Division. The latter, headed by 52-year-old Masao Furusawa, provided the foundation – or menu as Furusawa likes to describe it – for Rossi to refine the M1 into a package capable of claiming no less than nine victories from 16 starts in 2004.
Rossi’s ‘menu’ was decided well before the 25-year-old Italian signed with Yamaha for 2004, but the selection process and the development of the bike that followed began in earnest the first time Rossi tested in Sepang, Malaysia in January 2004. It was here the flamboyant Italian chose the direction for both the M1’s Deltabox aluminum chassis and its 220-plus horsepower engine – having initially had four of each to choose from. Based on these decisions the M1 found a new lease of life and continued to make significant inroads during pre-season testing before clinching its first unexpected win at the opening race held in Welkom, South Africa.
Engine
Engine type: Liquid-cooled, in-line, 4-cylinder, 4-stroke with 16-valve DOHC
Displacement: 990cc
Ignition: Magneti Marelli with adjustable mapping - NGK spark plugs
Carburation: Fuel injection
Lubrication system: Wet sump - Motul Oils
Data recording: 2D
Maximum power: More than 230ps
Maximum speed: Over 330 km/h
Transmission
Type: 6-speed cassette-type gearbox, with alternative gear ratios available
Primary drive: Gear
Clutch: Dry multi-plate slipper clutch
Final drive: Chain - DID
Chassis and running gear
Frame type: Twin-spar aluminium frame, multi-adjustable steering geometry, wheelbase, ride height, with aluminium swingarm
Front suspension: Fully-adjustable Öhlins inverted telescopic forks
Rear suspension: Braced aluminium swingarm with single Öhlins shock and rising-rate linkage
Front/rear wheels: 16.5 inch front, 16.5 inch rear, available in a variety of rim widths
Front/rear tyres: Michelin, 16.5 inch front, 16.5 inch rear, available as slick, intermediate, wet and hand-cut tyres
Front brake: Twin 320mm carbon discs with radial mounted four-piston Brembo calipers
Rear Brake: Single 220mm ventilated stainless steel disc with twin-piston Brembo caliper
Weight: 148kg, in accordance with FIM regulations
Fuel capacity: 22 litres, in accordance with FIM regulations
Yamaha YZR M1 -
06/05/2005, 16h16
Mode linéaire
