2016 YAMAHA YZ450FX ELECTRIC-START MXA RACE TEST: EVERYTHING YOU NEED TO KNOW

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MXA test rider takes the YZ450FX through a corner

The 1960s gave us a decade that changed America. JFK was president (until he was shot in 1963). Martin Luther King influenced the civil rights movement (until he was shot in 1968). The Vietnam war burned a scar in our history (with 58,000 American soldiers killed). The Russians positioned ballistic missiles in Cuba and started the Cuban Missile Crisis in 1962 (they blinked first). Malcolm X broke away from the Nation of Islam (until he was shot in 1965). Presidential candidate Robert Kennedy was shot by Sirhan Sirhan in 1968. But, the ’60s weren’t all gloom and doom. This was the age of Aquarius and flower power. Through the thick fog of cultural change, a pioneer by the name of Torsten Hallman came to America to spread the gift of motocross to the restless youth of a nation on edge.

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The sport of motocross spread like wildfire in the USA. Millions of American teenagers jumped at the chance to ride dirt bikes. The motorcycle world exploded. The manufacturers from Japan, Germany, England and Sweden rushed in to fill the demand for motocross bikes, trials bikes, enduro bikes, desert bikes, trail bikes, play bikes and any kind of bike that could be ridden in the dirt. Within a few short years, the manufacturers were selling 1,000,000 dirt bikes a year. Motocross bikes led the technical charge, with most of the cutting-edge development going into race bikes and then trickling down to the offroad market. As unique as the demands of offroad riding and racing were, most of the enduro models were heavy bikes with choked-down engines, kickstands, oversize tanks and a headlight. This formula worked well for the weekend warrior riding in the desert or woods, but hard-core offroad racers wanted more than leftover parts. Serious offroad racers eschewed the manufacturers’ enduro models and opted to take the high-end motocross versions, spending extra money to customize them into purpose-built offroad machines. The more this happened, the smaller the offroad market got—and one manufacturer after another dropped its offroad-specific bikes.

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The basic bones are YZ450F, but with major changes to the mapping, tranny, crankshaft and clutch. The exhaust is the same.

Then, a decade ago, KTM put the pieces of the offroad puzzle together. KTM decided to give offroad racers the lightweight, powerful, well-suspended bike they needed. It was basically a KTM motocross bike with only the absolutely necessary changes for offroad riding. The KTM XC line caught on fast with offroad racers. But, instead of rising to the KTM challenge, the bean counters at the Japanese firms shrugged off KTM’s sudden rise in the offroad world as small potatoes. They declared that the offroad market wasn’t big enough to justify building bikes for it. Gone were the PEs, ITs, RMXs and KDXs, with KTM rushing in to fill the vacuum.

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NOW, THESE MANY YEARS LATER, ONE JAPANESE BRAND HAS ELECTED TO STAND UP AND FIGHT THE ORANGE CRUSH.

Now, these many years later, one Japanese brand has elected to stand up and fight the Orange Crush. Last year Yamaha developed the YZ250FX offroad racer. Earlier this year Yamaha introduced the YZ250X two-stroke offroader. Now the company has completed the Yamaha triumvirate with the 2016 YZ450FX offroad racer. The simple fact that any Japanese manufacturer would release three completely new dirt bikes in a 12-month span is mind-boggling, especially given the doldrums they have been in since 2007. Better yet, Yamaha took the business model that was working for KTM and reproduced FX and X models that are comparable to KTM’s XC line. No harm done. KTM welcomes the competition.

Motocross can be an intimidating sport for new riders with its big jumps and high speeds. Most riders didn’t start their riding careers on a Supercross track. They rode in the woods, farm fields, vacant lots and desert. They had fun playing on their bikes and covering ground for the thrill of it. For them, Anaheim Stadium was not the ultimate destination. They looked towards the National Enduro, GNCC, AMA Hare Scrambles, AMA Cross-Country, SRA GP and WORCS series as the places to be. These races can draw over 1400 entries a weekend. Yamaha realized that these riders represented one-third of the dirt bike market, a third that it wasn’t reaching with its overweight and under-powered WR250 and WR450 machines.

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Will it do endurocross too?

FIRST GEAR ON THE YZ450FX IS 14 TEETH LOWER THAN ON THE YZ450F. SECOND GEAR IS EIGHT TEETH LOWER. THIRD GEAR IS TWO TEETH LOWER. FOURTH GEAR IS IDENTICAL AND FIFTH GEAR IS FIVE TEETH TALLER.

Enter the YZ450FX. It’s new, but in truth it’s newer in intent than in hard parts. Here is a quick comparison between the 2016 Yamaha YZ450FX offroad bike and the 2016 Yamaha YZ450F motocross bike.

(1) Price. The YZ450FX costs $8890 and the YZ450F comes in at $8590. The $300 difference comes down to pieces added to make the FX more offroad-worthy.

(2) Engine. The engines are virtual carbon copies, with the same rearward slanted cylinder (including camshaft profile, titanium valves and piston), rearward exhaust ports, down-draft straight intake and front-mounted airbox. The crankshaft balance factor has been changed from 88 percent to 100 percent to lessen vibration. Additionally, the crank diameter has been increased to mate with the larger generator. Total inertia was increased by 2 percent to produce a more controllable power delivery.

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(3) Electric start. Without an electric starter, Yamaha had no chance of competing with KTM. An electric starter is a valuable asset in root-strewn woods, on mud-bogged enduro courses or on the side of Rocky Mountain singletracks. A larger-capacity generator was installed (14v 95w/5000 rpm to 14v 160w/5000 rpm) for the electric push-button starter (there is a kick starter also). Although electric starting adds weight because of the larger generator, battery and starter motor, most offroad riders will love that they don’t have to kick the bike over. We hope to find electric start on the 2017 YZ450F. We can dream.

(4) Clutch. With the slower speeds and tighter riding of cross-country races, the clutch takes more of a beating. Yamaha’s goal was to lessen lever-pull resistance by 10 percent while increasing durability. Yamaha did this by replacing four of the eight plates with 0.4 mm-thicker plates, adding a judder spring to preload the pack and reducing the actuation arm length by 5mm.

(5) Transmission. The YZ450F’s wide-ratio five-speed transmission suits a broad range of offroad speeds and different terrains. It has a 30-percent-wider range. Each gear of the five-speed transmission is different from the YZ450F’s motocross tranny (save for fourth gear). The primary ratio has stayed the same between the two models at 2.61, although the final ratio has changed from a 13/48 to a 13/50. The easiest way to explain the different ratios between gears is to give you the approximate rear sprocket difference between each gear. First gear on the YZ450FX is 14 teeth lower than on the YZ450F. Second gear is eight teeth lower. Third gear is two teeth lower. Fourth gear is identical, and fifth gear is five teeth taller.

(6) ECU. Technological advances with ECUs in the last few years have made tweaking an engine’s power curve a breeze. The powerband of the YZ450FX is distinctly different from that of the YZ450F. Most of the difference comes from the FX’s mapping curve. We are big fans of GYTR’s easy-to-use Power Tuner. For under $300, the Power Tuner gives you an array of different adjustment points for both fuel and ignition. You can make your own personal powerband.

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(7) Exhaust system. The wraparound pipe and muffler are identical on both models.

(8) Frame. The YZ450F’s aluminum-beam frame is unchanged for the YZ450FX, although the front and upper motor mounts are 2mm thinner to reduce rigidity.

(9) Radiators. The radiator fin pitch was increased from 3.5mm to 4mm. This ensures stable cooling performance at both high and low speeds. The radiator shrouds on the YZ450FX have been lengthened by 30mm to capture more air at low speeds. For improved low-speed cooling, Yamaha offers an easy-to-install radiator fan kit for $69.99.

(10) Suspension. The Yamaha YZ450FX offers the same class-leading Kayaba SSS suspension as the YZ450F, but with a few small refinements to the settings and spring rate. For a plusher feel, the fork spring rate was reduced from 5.0 N/m to 4.5 N/m, and the internal shim stack was lightened up. The rear spring remains the same; only the shim stack is altered to be softer. These changes allow the fork to run lower in its stroke and improve cornering.

(11) Rear wheel. The 18-inch rear wheel is a must-have for offroad riding. The large air volume helps prevent pinch flats, while the bigger sidewall grip absorbs rough terrain better than the lower-profile, 19-inch rear wheel.

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The YZ450FX got the 270mm front rotor. This is a must-have for any offroad rider from the desert to the woods.

(12) Front brake. We were elated that the 270mm oversize front rotor from the 2016 YZ450F comes on the YZ450FX.

(13) Skid plate. Another must-have for offroad conditions is a skid plate. The YZ450FX comes with a simple plastic skid plate that protects the cradle of the frame and slides smoothly over anything it comes in contact with. Many riders will want to upgrade to an aluminum skid plate for more protection.

(14) Odds and ends. Other differences between the two models are the aluminum kickstand (most racers take off), D.I.D O-ring chain and offroad-specific Dunlop AT81 front and rear tires.
As with the YZ250FX and the YZ250X, the YZ450FX is a machine that can be competitive in offroad racing. But given that the YZ450F is one of the heaviest motocross bikes you can buy in 2016, the YZ450FX is doomed to be on the heavy side as an offroad bike. The inherited genes of the YZ450F have both pluses and minuses—and weight is on the negative side of the equation. We have to admit that the Kayaba SSS suspension is plush, and overall the YZ450FX setup allows it to turn better than its motocross brother. The engine is extremely torquey and stays connected in all but the roughest conditions.

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THE INHERITED GENES OF THE YZ450F HAVE BOTH PLUSES AND MINUSES—AND WEIGHT IS ON THE NEGATIVE SIDE OF THE EQUATION.

Since the MXA gang is motocross-minded, we also rode the YZ450FX on the motocross track. It handled most track obstacles fine, but it was heavy in the air. If we had to rate Yamaha’s three new offroad entries by their overall usability as both a trail bike and motocross bike, we’d pick the YZ250X two-stroke as a slam-dunk machine. It is light, agile and blessed with the ability to be ridden offroad or raced in motocross. It’s a great bike, but hampered a little on a motocross track by the gap between third and fourth gears. The YZ250FX is second overall. It benefits from a detuned version of the YZ250F’s brilliant powerband but suffers on a motocross track because of its wide-ratio gearbox and tall seat height (to make room for the electric starter’s battery box). While that leaves the all-new YZ450FX third in the Yamaha cavalcade of offroad models, we still think that it represents a viable option for offroad racers looking for a 450 with awesome suspension, usable power and refined handling. But, it wouldn’t be a viable choice as a motocross race bike because of its weight. The YZ450F motocross bike is heavy at 238 pounds, the 247-pound YZ450FX is really heavy.

Yamaha deserves credit for fighting back against KTM’s dominance—and these three bikes will most likely open up riding possibilities to new clientele, which could translate into more people riding, racing and having fun.

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