2 STROKE POWER TUNED FOR OFF ROAD
Nearly every functional part of the engine is new — from the cylinder body, cylinder head, piston, piston pin, connecting rod, crankcase and expansion chamber, to a revised cylinder port shape and updated cylinder port timing. It's a change that is immediately apparent at the first crack of the throttle and throughout the entire rpm range.
YZ BASED FRAME
A race-proven, highly developed aluminium semi-double cradle frame is engineered to provide the perfect balance of rigidity and flex for competition-ready handling character and composure. Removable aluminium rear subframe is constructed of square-section tubing for reduced weight.
The YZ125X comes equipped with an 18-inch rear wheel, larger rear sprocket, side stand, sealed O-ring chain, new headlight, reserve fuel petcock, and newly adopted scraper between the fork's dust and oil seal, all adding up to exceptional off-road performance.
A racy ‘gripper' type seat and narrow fuel tank combine with a tapered aluminium handlebar and adjustable mounts to create greater freedom of movement and more comfortable ergonomics for riders.
ENDURO-SPECIFIC WHEELS AND TYRES
Cross-country-spec Dunlop Geomax MX33 tyres front and rear are ready to head straight to the races. An 18-inch rear tyre has a taller sidewall to improve comfort and reduce pinch flats.
INDUSTRY-LEADING KYB FORK
Industry-leading, fully adjustable KYB spring-type fork with speed sensitive damping uses piston speed to control damping force for super-precise handling and a smooth ride, with minimal wasted stroke or abrupt shocks for the rider – all tuned for the demands of off road racing.
HIGH EFFICIENCY ANGLED RADIATORS
To ensure that the new more powerful engine runs efficiently in all conditions, Yamaha's engineers have developed radiators that are angled to directly face the incoming air. By maintaining a consistent airflow, this angled radiator layout delivers effective engine cooling for winning performance. A thermo fan cuts in to keep the fluid cool when the going gets tough.
TOUGHER WIDE RATIO 5-SPEED TRANSMISSION
The WR450F's robust 5-speed transmission is built to handle even the most aggressive left foot. The specially-developed gears feature a large surface area that spread the load, and third and fourth have received a surface treatment to increase durability. In addition, the shift drum and selectors now give improved feel and a shorter stroke when shifting gear. Ratios are ideal for enduro riding with lower gearing from first to third gear and taller-geared fifth compared to YZ450F.
MASS-CENTRALISED WRAPAROUND EXHAUST
A key feature of the WR450F is its mass centralised design, in which major components are located as close to the bike's centre of gravity as possible. One example of this is the wraparound exhaust that snakes around the cylinder - this design also enables the fitment of a muffler that is mounted close to the bike's centre. The WR450F runs a YZ450F exhaust with WRF specific muffler to achieve the goal of increased power with control. Combined with the rearward-slanted cylinder, the exhaust centralises mass and contributes significantly towards lightweight and dynamic handling performance.