Yamaha WR 450F 2-Trac Dakar

Yamaha says that the WR450F is the most successful 450cc machine in the Dakar.  In the hands of David Frétigné, the machine won the 450cc class in 2005 and 2006, while Helder Rodrigues finished ninth overall with the bike in 2006.

As renowned innovator Yamaha pioneered with the WR450F in 2004 against the big capacity 1000cc twins.  The light and nimble machine performed above everybody’s expectation and won three stages in 2004, finishing seventh overall, a year later the WR even finished fifth overall.

Traditionally the WR450F is equipped with a high-performance DOHC 5-valve mono cylinder engine that is tuned to deliver remarkably strong power in the low to mid range.  The engine is mated to a steel semi-double cradle frame, making the 2006 WR a proven concept that combines high reliability with winning performance.

In the punishing Dakar rally a bike not only needs to be fast, but also be predictable, give ample feedback to the rider, and most important, be forgiving when the rider makes a mistake.  All these qualities the WR offers in abundance and make it to one of the preferred weapons of choice.

What makes the WR450F truly unique is that it can be equipped with Yamaha’s revolutionary "2 Trac" two-wheel drive system.  This system provides drive to the front wheel and improves traction and increases stability. 

Developed by suspension company Öhlins, 2-Trac uses a hydraulic pump located on top of the gearbox to force hydraulic fluid into the special front wheel hub.  The hub contains a hydraulic motor, which is set in motion through the pressure of the fluid, to provide drive to the front wheel.

The pressure, and consequently the pulling power on the front wheel, varies depending on the amount of rear-wheel spin.  Sensors allow the system to regulate itself and apply the most appropriate ratio of power between front and rear.  The system gives the rider great benefits in the deep desert sands where 2 Trac delivers unrivalled traction and stability.

The motorcycles in the Dakar can compete in different specifications, either in "Marathon" or in "Super Production" guise. 

The first category are standard machines that only have the essential modifications done to survive in the rally, while the latter super production category are heavily modified prototype bikes.

Every team will make their own modifications, but many Yamaha WR riders opt for the "Kit Afrique" that Yamaha Motor France offers as a base to work from. This kit looks after all the standard modifications (shown in the photo above) necessary for desert racing such as:

• Double front fuel tank with enlarged capacity and double rear fuel tank with a total capacity of 45 liters 

• Vacuum fuel pump
   

• Fairing with screen for rider protection at high speeds and double xenon head lamps
   

• Instrument panel including GPS system, tripmaster, roadbook holder with lighting
   

• Carbon fiber skid plate for engine protection with integrated tank for drinking-water
   

• Special low slung exhaust system
   

• Raised triple clamps and handle bar
   

• Modified disk brakes front and rear for higher performance
   

• Modified rear shock settings

Source  web Bike World