2010 Yamaha YFZ450X

Leaner, Meaner and Fits Better In-betweener

Yamaha has been living proof of the age-old adage “the rolling stone gathers no moss” these days.  No sooner does the proverbial dust settle on news of the new-from-the-ground-up YFZ450R motocross-ready ATV, Yamaha follows up with another 450cc entry for 2010; this one designed specifically for the rigors of trail riding/ GNCC-style competition.  Enter the YFZ450X, Yamaha’s latest sport/ performance quad that in following in the footsteps of brands like KTM and Can-Am, takes into consideration the fact that XC racers and woods riders have different needs than their motocross counterparts.

The Lineup

Before we take a look at the new model, let’s establish where the YFZ450X sits in Yamaha’s model line.  For 2010 Yamaha has decided to remove the time-proven “standard” steel-framed YFZ450 (originally introduced in 2003) from their lineup.  Rather than flood their potential 450cc customer with options, this year Yamaha will have two models based on the new aluminum-framed architecture: the 450R & 450X.

As the name-codes suggest, the R version has closed circuit/ motocross competition in mind while the X introduces a host if innovations designed specifically for woods riders, XC racers, and GNCC competition.

What’s New

If you want to be technical, everything on this model is “new” on account of the fact that it is based on the YFZ450R platform that was just introduced a few months ago for the 2009 model year.  A more accurate question would be “what’s different between the two?”  The answer can be summarized as decreased width (46-inchs apposed to 50), slight weight reduction, specifically tuned (softer and shorter) suspension, tweaked steering geometry and a reprogrammed fuel map.

While it is true that the X works from the same weld-less aluminum frame that was designed specifically for the R, it should be noted that the bottom portion has been swapped out in favor of a high-strength steel section built to withstand the type of bashing that comes with straddling roots, rocks, and stumps.

The power plant is essentially the identical 449cc titanium 5-valve DOHC liquid cooled single that powers the R with the notable exception coming in the form of the factory fuel mapping.  Rather than metering its power spread for maximum top-end hit (which is essential for drag racing down straight-aways and clearing big jumps), the X’s power curve places more of the meat down low where it can be used to conquer technical trails, steep hill-climbs, and mud pits.

From a glance it may appear that the geometry is basically the same as the standard YFZ450 that was dropped from the line but careful examination reveals that nothing if further from the case.  To achieve the same 46-inch width as the old YFZ, Yamaha designed a new front end (with shorter A-Arms) and took 50mm from the R’s rear axel.

The all new front and rear wheels have been beefed up for rock dusty and the aluminum seams have been inverted to keep from filling with trail-goop.  In all the YFZ450X manages to lose five-pounds over its R equivalent and comes in at a dry weight of 400 pounds.

 

The Ride

Saddling up on the new Yamaha 450X reveals an immediate sensation of nimbleness even before you touch the electric-start button.  The entire package simple feels more maneuverable, compact, and softer than a comparable MX-specific 450.  The machine fires up with only the slightest depression of the bar-mounted button and reveals a steady exhaust hum that’s neither overly loud nor barky when revved.

The differences in the fuel mapping are immediately apparent as the 450X offers gobs of usable low-end.  Riders will find themselves short shifting through the gearbox on long straights or vast fields but ridiculously comfortable with 2nd or 3rd gear once the going gets tough and technical.  Power is abundant enough to keep the machine percolating at idle in nearly any gear with an impressive surge of torque at the rider’s beckoning call with merely a little more throttle application.

As such we never once found ourselves in an ugly situation on the rugged east-coast trails that demanded a panicked downshift or an early up-shift to avoid revving out.  If the powerband of the YFZ450X can be summarized in a single word, that word would be “usable”.

The suspension is also much more trail-friendly than the 450R (or any of the motocross-oriented 450s for that matter) with much more small-bump compliancy especially early on in the travel.  Rather than deflect off or skip over the rough stuff, the 450X’s shocks remain extremely active, absorbing terrain imperfections while keeping all four of the wheels on the ground.  While we hadn’t an opportunity to sample the suspension’s big-hit absorbing capabilities, the few step-ups and drop-offs that we encountered on the muddy trails revealed no spikes or harsh bottoming tendencies.

Especially welcomed was the inclusion of 20-inch rear tires (opposed to the 18’s that come standard on the MX machines) thanks to increased ground clearance and less of a inclination to spin-out or break free when getting on the gas.  Surprisingly enough (or maybe because of it), the YFZ450X’s hardy low-end seems to work really well when a rider keeps on the throttle then brakes hard and late.  It’s been our experience in the past that smooth-trail motors usually like to be finessed with flow and careful line selection to carve fast laps but the 450X isn’t afraid of a little slam-and-jam style either.  The machine’s light weight coupled with a rigid chassis and active suspension all add up to an ATV that carries speed through even the roughest corners.

Conclusion

The all-new Yamaha YFZ450s are spectacular testaments to the company’s commitment to the performance ATV scene.  Woods riders whose typical loops include tight double track, silt, mud, stones, roots, and mud will absolutely adore the 450X.  XC racers and GNCC competitors will appreciate not having to spend big bucks modifying their 450cc MX quad to be competitive.

It’s a pretty safe bet to say that YFZs are going to be spotted on trails around the globe in 2010 but it’s the competition that’s going to be feeling blue.

Specs

Engine Type: 449cc, liquid-cooled w/fan, 4-stroke; DOHC titanium 5-valve Bore x Stroke: 95mm x 63.4mm

Compression Ratio: 11.6:1 Fuel Delivery: Yamaha Fuel Injection (YFI), 42mm

Ignition: TCI (Digital)

Starting System: Electric

Transmission: 5-speed manual clutch

Drive Train: 2WD; Sealed O-Ring Chain, Eccentric Adjustment Front

Suspension Front: Independent Double Wishbone, 9.4”. Kashima Coated Piggy Back Shocks, High/Low Speed Compression, Rebound and Threaded Preload Adjustment

Suspension Rear: Cast Aluminum Swing Arm, 11.0”. Piggy Back High/Low Speed Compression, Rebound and Threaded Preload Adjustment

Front Brakes: Dual Ventilated Hydraulic Disc, Twin Piston

Rear Brake: Wave Style Ventilated Hydraulic Disc, Twin Piston

Front Tires: AT21x7-10 Radial

Rear Tires: AT20x10-9 Radial

Length/Width/Height: 70.7 x 46.1 x 41.9

Seat Height: 31.9 in

Wheelbase: 50.0 in

Ground Clearance: 4.5 in

Fuel Capacity: 2.6 gal

Curb Weight: 400 lb

Lighting: 30W Krypton Multi-reflector Headlights and 3.9/0.5W LED Brake light

MSRP: ,499

http://www.yamaha-motor.com/sport/products/modelhome/635/0/home.aspx