|
Yamaha
WR 450F 2-Trac Dakar
|
Make Model |
Yamaha
WR 450F 2-Trac Dakar |
|
Year |
2004 |
|
Engine |
liquid cooled,
four stroke, single cylinder, DOHC, 5 titanium valve per cylinder. |
|
Capacity |
449 |
|
Bore x Stroke |
95
x 63.4 mm |
|
Compression Ratio |
|
|
Induction |
Keihin FCR 38/41mm |
|
Ignition /
Starting |
YRRD Computer adjustable CDI |
|
Max Power |
41 hp |
|
Max Torque |
|
|
Transmission /
Drive |
5 Speed / chain |
|
Front Suspension |
48mm Upside-down forks |
|
Rear Suspension |
Monocross
with Factory
Kayaba gas shock
absorber |
|
Front Brakes |
Single 270mm disc |
|
Rear Brakes |
Single 245mm disc |
|
Front Tyre |
20/21 inch |
|
Rear Tyre |
19 inch |
|
Dry-Weight |
112 kg |
|
Fuel Capacity |
2 x
16 Litres & 2
x 6 Litres |
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 |
