YFZ450X Test

[Midwest Trail Rider]

Although you can’t please all the people all the time, Yamaha is making every effort to do just that. Team Tuning Fork unveiled the all-new, trail-friendly 2010 YFZ450X to compliment its existing motocross-aimed YFZ450R. The YFZ450X replaces the carb-fed YFZ and improves Yamaha’s ability to please the vast majority of 450 sport customers.

“[It’s] almost impossible to cover this market with one model,” explained Travis Hollins of Yamaha’s ATV and SxS product planning division. “That’s why both the YFZ450R and YFZ450 existed for 2009.”

Hollins said the R and X models now give Yamaha the best coverage for this segment of the market. And we wholly agree. While neither YFZ comes “race ready” (read: nerf bars, race tires, kill switch, etc.), they are designed for extended comfort, improved handling and each excels in its specific niche of the market.

The YFZ450X was made for the forest and trail riders. It’s narrower than the R version and has numerous other tweaks to improve its handling between the trees.

We told readers about the YFZ450X in the last issue, but now we’ve had a chance to test it on the Big Buck Racing course, which is located in South Carolina’s Piedmont Region. A full day of seat time gave us quite an impression of this new woods warrior.

Proving Grounds


The 2010 YFZ450X uses the same frame geometry as the YFZ450R but has a shorter axle, A-arms and shocks.
Not any old forest would work as the proving grounds for the YFZ-X. If you’re going to offer a high-performance sport quad for the woods, you may as well test it in its intended environment. The Big Buck property is just such a place.

Having made weekend heroes out of dirt bike and ATV racers the past 13 years as part of the Grand National Cross Country (GNCC) series, the 600-acre Big Buck has a reputation as a rugged woods course. Mother Nature should be proud of this natural-terrain obstacle course, complete with ruts, rocks, slick clay, a creek jump, gullies, dense tree sections and high-speed pastures.

Yamaha took it a step further and hired GNCC course designer Buren Hamrick to cut a virgin trail and provide the test editors with even narrower corridors through the forest.

“I told them that I wanted the tightest stuff you got,” said Pat Biolsi of Yamaha’s testing department. Then, Factory Yamaha’s Bill Ballance and Traci Cecco tested the 10-mile course before we arrived to ensure it was up to snuff and would challenge man, woman and machine.

Model Changes
Clearly the new YFZ-X model is narrower than the YFZ450R version but it also is 5 pounds lighter thanks to altering the axle and front-end design and shocks. At 46.1 inches wide, it is a full 2.7 inches skinnier. Biolsi describes it as “confidence-improving width” for woods riders. That’s the same width as the old YFZ, but the X version has longer A-arms (+23.4mm), 4 degrees of caster and a 50mm narrower axle. The rear hubs, with 20mm less reach than the R, were carried over from the original unit.

Yamaha used a new Wide-Arc A-arm configuration and says it improves ground clearance as well as handling. How? It has to do with the YFZ’s narrower chassis and frame rails. With closer A-arm mounting points, the A-arms are longer and reduce camber during the suspension travel. The end result is less bump steer and improved steering. The machine’s trail has dropped by 3mm, too.

The front shocks have the same adjustments as the YFZ450R, with a threaded body for easy preload changes, plus low- and high-speed compression adjustments through the clickers. The shocks also feature improved cooling and increased size.

Compared to the old YFZ, the new X model has longer, thicker shocks with 2mm more stroke. However, the YFZ450R and YFZ450X shocks differ ever so slightly. The shocks have a different leverage ratio, slightly less travel (and the first spring, K1, is a bit stiffer). They’re also shorter and have a tapered body to reduce friction and scratching.

Basically, like the YFZ450R, the YFZ-X version is all-new and shares only a few parts with its predecessor, the standard YFZ450. Only the Pro Taper handlebars, grips, clutch lever, perch, parking brake system and lever, rear brake caliper, front master cylinder, lever and front calipers, discs, pads and air filter element were reused.

Test Ride

The X benefits from the R arriving first. They share many engineering designs and comfort levels. Aside from being skinnier than the 450R, the


With a narrower width and reconfigured suspension package, the Yamaha YFZ450X is designed to dominate in the woods and compliment its MX-ready brother, the YFZ450R released last year.
YFZ450X feels very similar to its motocross-ready brother.

However, you have to remember to compare the 450X to the old YFZ450 platform to understand the real benefits of the new machine. The ergonomics package alone is enough to like the 450X better than the original; however, we also love its handling, suspension and power. Electronic fuel injection is huge, too. We can no longer complain about the YFZ’s tiring thumb throttle, as the new mechanism, thanks to EFI, is very smooth.

The new seat, which debuted on the YFZ450R, offers an entirely different feel than the YFZ’s old-school platform. Where the old seat was thin and had uncomfortable inner seat rails, the new one is plush enough for all-day comfort and features an ideal design for performance riders. The inner seat rails are less noticeable (good news for your tailbone) and the rear seat flares offer improved comfort for aggressive cornering. Yet, it retains a low-profile and narrow shape up front for improved tank hugging. Perfect!

The improved ergonomics also include wider and longer foot pegs, good news for your feet. Complete with up turns, these 65mm pegs provide a more comfortable platform for standing and sitting and ensure your boots stay on the pegs. And for those riders who need to fine-tune the ergonomics, Yamaha engineers added a four-position handlebar mount. At 6-foot tall, we found the bars’ stock location to be fine, but a few taller riders moved the Pro Taper bars forward and rotated up a few degrees.

You’d think the narrow design would create a less stable platform, but the YFZ tracks true and isn’t tippy. In fact, when we were on the gas, the YFZ450X felt like a slot car on some of the curvy sections in the woods. To dice through the trees, we simply had to shift our weight and maintain a steady throttle and the Yamaha danced and skirted around and between the trees with expert precision.

A few locations at Big Buck featured off-camber and rutted hills that tested the machine’s stability. The YFZ surprised with its nimble quickness. The suspension — which may be the best stock setup in the industry — is huge when it comes to trail handling.

Big Buck also featured a rutted and rough open section complete with whoops, odd divots and high-speed sweepers. A section like this was an ideal location to thoroughly test the stock KYB shocks. We’ve ridden other stock setups in similar situations and have been bounced silly. However, the Yamaha’s shocks provided a very controllable ride, even at higher speeds. Its ability to maintain traction while pounding through this rough section made the YFZ easier to control and the ride far less fatiguing.

Speaking of control, the YFZ450X EFI mapping was slightly altered from the MX model. The X was changed to accommodate a throttle control, Yamaha engineers described as “blipping.” Unlike MX riders, woods riders blip the throttle or repeatedly press and release the thumb throttle for optimum torque or to improve a machine’s ability to lug a taller gear.

The pine section at Big Buck showcased this exact skill. This portion of the course was the narrowest of all and was filled with several super-tight, slow-speed chicanes that forced us to lug it in second gear or rev out in first. The new fuel mapping and reconfigured frame and suspension made the new YFZ easier to manage in these technical areas than the old machine.

Smooth Mover


A full day of seat time gave us quite an impression of this new woods warrior.
Yamaha is offering a Bill Ballance edition YFZ450X ($8,799) in honor of its multi-time GNCC Champion. The model features a blue chassis, gold DID chain, silver wheels, blue side panels, GYTR front grab bar, Ballance Racing graphics, quick-release fasteners and darker gold shock bodies.

The more we rode the YFZ450X, the more we appreciated it. The first lap on the brutal Big Buck course was tiring, but it wasn’t the Yamaha’s fault. Once we got used to the machine and knew what to expect from the woods course, we found the X to be an ideal performer. The new width is perfect for carving through the trees. The engine and EFI produce a great mixture of a smooth throttle control (unlike the old YFZ!), usable traction and acceleration in the open fields. Yamaha now has two performance 450s that can cater to any type of rider and terrain.

Yamaha YFZ450X Specs

$8,499 (Available in Team Yamaha Blue, white/red)

Engine: 449cc liquid-cooled (w/fan), four-stroke single

Bore X Stroke: 95mm x 63.4mm

Fuel Delivery: Yamaha Fuel Injection, 42mm

Starting: Electric

Transmission: 5-speed manual clutch

Drive: 2WD; sealed O-ring chain, eccentric adjustment

Suspension, front: Independent double wishbone w/Kashima coated piggyback shocks, high/low speed compression, rebound and threaded preload adjustment, 9.4 inches of travel

Suspension, rear: Cast aluminum swingarm w/piggyback high/low speed compression, rebound and threaded preload adjustment, 11 inches of travel

Brakes, front: Dual ventilated hydraulic disc, twin piston

Brakes, rear: Wave-style ventilated hydraulic disc, twin piston

Tires, front: AT21×7-10 radial

Tires, rear: AT20×10-9 radial

L x W x H: 70.7 x 46.1 x 41.9 in.

Seat Height: 31.9 in.

Wheelbase: 50.0 in.

Ground clearance: 4.5 in.

Fuel capacity: 2.6 gal.

Wet weight: 400 lb.

[xzpolskix]

Good to see stuff going FI. God do I HATE carbs!

[Midwest Trail Rider]

It makes tuning possibilities basically endless and makes for a MUCH more manigable powerband...

[kingofhill21]

Dyno Jet has a commander V programmer for the YFZ450X you can get the option for an auto tuner where it tunes its self useing the exhaust o2 sensor.

[Midwest Trail Rider]

I know its much easier than jetting and it's gotta have way better power gains but those things a freakin expensive. I guess the more tech the bikes have the more we pay. The YZ is even beter though and come with a tunner. I watched the mechanic at my local dealer change the fuel curves and the powerbands on one of those things about a month ago...