Power to the people

YMA is pleased to announce the release of the 2011 YFM450 Grizzly Auto 4×4 that features some major changes including the fitment of electronic power steering.

Engineered, tested and built tough, the key enhancements include a lighter one-piece frame, redesigned wet brake system, higher AC generator output and a more durable rear gear assembly.

These changes result in an overall weight reduction and improved ergonomics for a more comfortable and agile riding experience.

The Grizzly 450 has been a popular choice of professional and recreational riders since its introduction in 2005. It combines the versatility, durability and pulling power of a utility ATV with the handling and comfort that trail riding demands.

This year’s model retains the renowned features that set its predecessors apart from the competition. Like Yamaha’s push-button On-Command┬« drive system, which ensures solid driveability over varied terrain by allowing riders to rapidly switch between 2WD, 4WD or 4WD with differential lock. And, fully independent double-wishbone suspension at front and rear that maximises wheel contact over ruts and bumps to allow more traction and a smoother ride.

2011-yamaha-yfm450fap-power-steer-grizzly-auto-4x41Like its big brother Grizzly 700, the Grizzly 450 incorporates the Ultramatic┬« transmission system. Yamaha’s Ultramatic┬« transmission uses both a centrifugal and a sprag (one-way) clutch. This configuration minimises belt slippage by keeping the belt tight at all times, which increases the life of the drive belt. It also provides superior engine braking, allowing riders to tackle steep downhill gradients with confidence.

Yamaha’s engineers have made several enhancements to the chassis that give the Grizzly 450 a sportier feel without compromising durability. The new one-piece frame increases rigidity and strength while reducing weight by 2.7kg. The stabiliser bar has been shortened and its stiffness has been increased with 20% to match the new frame dynamics. The rear gear assembly has been completely redesigned, switching from a two-point mounting system to a three-point system. This to add extra structural strength to the rear chassis as well as improving force deployment while accelerating, riding over rough terrain or braking.

The Grizzly 450’s SOHC, 2-valve engine is known for its workhorse reliability, providing plenty of low-end torque for tough jobs around the farm or steep climbs on the trail. The engine benefits from a new high-output AC generator assembly with new rotor, stator and regulator, resulting in 39% more output at 3000 rpm.

With a maximum output of over 320W, a full battery load is guaranteed and plenty of power is available for operating winches or other electrical equipment. Combined with today’s battery technology it eliminates the requirement of a pull start device, effecting in a weight reduction and offering more space on the footboard.

The multi-disc sealed rear wet braking system has been completely redesigned. In its new configuration it moved from its lateral position and is now connected to the pinion gear, resulting in a firmer brake feel with better feedback. The new configuration supports an in-line brake adjuster for easier maintenance. Coupled with dual hydraulic discs up front, the rear wet brake provides consistent stopping power in all kind of conditions.

The 2011 Grizzly 450FAP Auto 4×4 brings a number of refinements that make handling more nimble and long journeys more comfortable. The steering column receives a new column bearing with a larger surface area to provide smoother handlebar movement. Constructed from newly developed TPU (Thermoplastic Poly-Urethane), the bearing is a two piece design with integrated seals that retain grease better and make servicing easier.

The new Maxxis tyres – the MU13 (AT25x8-12) at the front and the MU14 (AT25x8-12) at the rear – take 2 kg from the Grizzly 450’s unsprung weight. The modified tread pattern improves overall handling.

The seat has a new ergonomic shape with a special PVC cover that is more puncture resistant and flexible in low temperature environments. And, like its bigger siblings the Grizzly 550 and Grizzly 700, sections of the Grizzly 450’s rear fender have a textured finish that offers extra scratch protection from the unavoidable rider’s boots.

Grizzly 450 EPS: A world first
Introduced to the ATV market by Yamaha in 2006, Yamaha’s EPS system has now been brought to the mid-sized ATV segment for the first time in response to feedback from Yamaha customers. This speed-sensitive system greatly reduces the physical effort demanded of riders, lowering fatigue levels on long working days or expeditions.

In addition to easing the steering effort, the EPS system dampens any steering kickback. The Grizzly 450 EPS uses the same system as the Grizzly 700 EPS, but with a new mapping to suit the unique riding characteristics of the Grizzly 450. The new AC generator assembly delivers sufficient output to power the EPS system under any conditions.