Yamaha WR 450F

The perfect combination of YZ250F-based suspension and 450F power makes for the ultimate trail machine...

The Yamaha WR450F offers 3 main advantages over its competition; an easy to ride demeanor, unparalleled reliability, and the versatility to win in a number of different racing disciplines. Featuring a proven 5-valve engine design, the biggest WR also sports a Keihin fuel injection system, a lightweight aluminum Bilateral Beam frame and YZ based suspesion.

YZ250F Style Chassis plus a 450 Fuel Injected Engine equals Perfection

The Yamaha WR450F features a powerful and reliable, high revving, five titanium valve engine with fuel injection, YZ250F bred advanced aluminum frame, latest generation YZ forks and shock and slim bodywork with updated headlight design gives the 2013 Yamaha WR450F an aggressive, tough stance. Plus it's green sticker approved for California.

You might not know where the trail will take you, but with the WR450F, you know that you'll get there and back again.

Yamaha's WR450F is ready to tame the roughest single track or attack a Hare Scrambles course with its adjustable YZ based 48mm Speed Sensitive System fork and fully adjustable KYB piggyback shock. But the YZ connection does not stop there; the YZ250F inspired Bilateral Beam aluminum frame provides light, nimble handling while the YZ250F bodywork means fast, easy rider movements. Oh yeah, the YZ based brakes with wave -style rotors stop things in a hurry too. The WR450F, designed to deliver winning performance on the track and all day versatility and fun on the trail.

Yamaha WR450F Key Features

Fuel injected, 5-valve, 449cc powerplant

Compact Bilateral Beam frame and YZ Speed Sensitive 48mm fork

A YZ-bred advanced aluminum frame—carefully engineered forgings and extrusions—enhances handling while retaining legendary Yamaha feel and characteristics.

Highly evolved five-titanium-valved engine starts with the push of a button.

Highly functional digital enduro computer offers speedometer, clock, tripmeter, etc., in basic mode—or pace management functions such as timer, distance-compensating tripmeter, average speed, etc., when switched to race mode.

The WR450F is green sticker approved for California.

Yamaha WR450F Features and Benefits

Engine:

•Fuel injected, liquid-cooled, 449cc, DOHC, 5-valve, 4-stroke powerplant with super light titanium valves. Selected items such as camshafts, exhaust and ECU settings are specially designed for enduro type riding.

•Super convenient electric starting means fast, sure starts and is backed up by a manual kick starter.

•Hassle free automatic decompression system ensures fast restarts in any gear.

•Magnesium cylinder head cover helps reduce weight.

•Optimized cylinder inclination angle (4.5 degrees) to centralize mass and bring the center of gravity closer to the rider for mass centralization and light handling.

•Optimized intake port shape increases the velocity of the incoming charge for more complete cylinder filling and more power.

•Titanium valves and load-reduced springs decrease weight by more than 40% over a conventional steel valve train and reduces reciprocating mass for faster-revving and smoother-hitting power delivery across the rev range.

•The lightweight aluminum cylinder features a ceramic composite coating which is applied directly to the aluminum, eliminating the need for a heavy iron sleeve. The ceramic coating insures faster, more uniform heat dissipation, reduced friction and a longer service life.

•Cylinder design features cutaways that allow the air trapped under the piston to enter a side chamber (or cutaway) to reduce horsepower-robbing "pumping losses."

•The crankcase also utilizes cutaways to reduce "pumping losses". The crankcase cutaways match the cutaways in the cylinder.

•Crankcase design features an integrated dry sump oil tank inside the front area of the engine cases. This design centralizes mass and reduces the centre of gravity for improved handing and a lighter feel.

•The crankcases features a "tri-axis" design layout for the crankshaft, main and drive axles. This tri-axis design keeps the crankcases more compact while also centralizing mass for better handling. All of the shafts are positioned as low as possible in the cases to maintain a low centre of gravity.

•Special cam shaft profiles provide outstanding low to mid range power well suited to enduro style riding. The WR450F offers a wide spread of linear torque from low to peak rpms.

•Ball bearing style lightweight crankshaft provides fast throttle response.

•Engine balancer shaft optimizes vibration for excellent rider comfort and reduced fatigue during long rides.

•Lightweight, short-skirt, forged piston offers great durability and reduced weight for fast engine response.

•Piston oil cooler utilizes a pinpoint nozzle that directs oil to the desired portion of the cylinder and piston, to reduce piston, cylinder and rod temperatures for excellent durability.

•Oil volume in engine has been optimized to reduce weight and oil "drag" related power losses.

•Compact automatic cam chain tensioner reduces maintenance and mechanical engine noise.

•Keihin 42mm throttle body fuel injection system. This is an open loop system and features a throttle position sensor (TPS).

•The 12-hole fuel injector maximizes fuel atomization for more complete combustion and great power output.

•The fuel injection system has been designed with a capacitor, which allows hardcore riders the option of reducing even more weight by removing the battery and starter motor if desired.

•The benefits of fuel injection include optimum fuel - air ratio regardless of outside air temperature or altitude. Other benefits include excellent starting with no choke to fuss with, improved throttle response, reduced fuel consumption and reduced emissions. There is a conveniently located idle adjusting knob on the side of the throttle body.

•Compact, lightweight in-tank electric fuel pump

•High capacity ACM (alternating current magneto) is used to power the FI system and other electrical components

•Lightweight, compact, high powered 32 bit ECU. The ECU controls the fuel injection process and ignition timing.

•Lightweight direct ignition coil is integrated into the spark plug cap to reduce weight and complexity

•Wide ratio 5-speed transmission features gear ratios designed for enduro type riding and that match the torquey, linear, engine power characteristics of the WR450F engine.

•Heavy-duty multi plate wet clutch.

•Quick-access, lightweight magnesium outer clutch cover allows fast, easy access to the clutch.

•Lightweight dual radiators with special design louvers direct cooling air into the rads for maximum cooling.

•Washable, dual-stage, foam air filter can be accessed without tools via "Dzus-type" fasteners.

• Lightweight exhaust system features a stainless steel header pipe with titanium heat shield and an aluminum muffler. The exhaust features a resonator canister which helps create a more efficient exhaust pulse effect for improved low to mid power.

•Lightweight aluminum muffler features a "serviceable", screen-type spark arrestor which prevents sparks from exiting the exhaust.

•Oversize race-type "barrel adjuster" for easy, on-the-fly adjustability of clutch lever free play.

Chassis and Suspension:

•Compact "Bilateral Beam" aluminum frame centralizes mass for exceptional handling and incredible cornering ability. This frame consists of forged, extruded and panel aluminum parts. This frame is more compact than the last generation and offers significantly improved rider - machine communication" (a.k.a. feedback).

•The rigidity balance of this "Bilateral beam" frame has been optimized for enduro type riding. It contributes to a feeling of lightness, agility and traction.

•The head pipe (steering head), wheelbase, caster and trail dimensions are optimized to accentuate the engine and frame characteristics. The benefit is quick, direction changes with good stability.

•Removable rear sub frame is constructed of square-section, lightweight aluminum pipe. Its detachable design allows easy access when servicing rear suspension components.

•Lightweight, tapered, aluminum swingarm is produced using "hydro forming", a special method that uses high pressure water to form shapes. The swingarm design provides great overall chassis "balance" for precise cornering and a light handling feel.

• 48mm, adjustable inverted, Kayaba cartridge fork provide excellent suspension performance. This fork is based on the current YZ series with different setting specifically for enduro type riding. These forks feature a twin-chamber design which means the damper unit is in a separate structure which prevents aerated fork oil from entering the inner damper assembly and reducing its damping abilities. Since the inner damper is pressurized, it also eliminates bubbles forming in the oil. This fork design also features a Transfer Control Valve (TCV). The TCV enhances the damping force from mid to full stroke and improves bottoming characteristics. The benefit of TCV is more precise control throughout the full suspension stroke. The TCV is located on the upside of the spring and its function is controlled by piston speed, not piston position … hence the term "Speed Sensitive fork".

•Front wheel travel is 300mm (11.8").

•Front fork adjustments include: 20-way compression damping and 20-way rebound damping. Optional fork springs are available through Genuine Yamaha parts.

•Large plastic fork protectors wrap around the fork tubes for increased protection against dirt, mud and stone chips. These fork protectors are self-supporting to reduce friction for smoother fork operation.

•Cast aluminum upper and forged aluminum lower triple clamps reduce weight while providing excellent strength.

•Adjustable forged handlebar mounts allow the handlebars to be moved 10mm rearward if desired.

•Monocross rear suspension system features a fully adjustable, Kayaba piggy back style shock with separate adjusters for high- and low-speed compression damping. Rear wheel travel is 294mm (11.6").

•Shock adjustments include: spring preload, 20 clicks of low-speed compression damping, 2 turns of high-speed compression damping and 20 clicks of rebound damping.

•Link-type rear suspension provides a rising rate (progressive) suspension function. The linkage design is virtually the same as YZ-F series of MX bikes.

•250mm fully floating front disc brake with "wave style" rotor is squeezed by a twin piston Nissin caliper fitted with lightweight, aluminum pistons provides excellent braking performance.

•"Shorty style" adjustable front brake lever

•245mm rear disc brake with lightweight wave style rotor is squeezed by a compact single piston Nissin caliper. The rear master cylinder is an integrated design (fluid reservoir is integrated into the top of the master cylinder to reduce weight) and delivers strong, progressive stopping power with excellent control and feel.

•Rugged, Excel 21" front and 18" rear rims provide exceptional durability and help reduce unsprung weight for optimal suspension performance.

•High tech, lightweight digital meter assembly. This compact meter features: speedometer, dual tripmeters, odometer and a clock in the basic mode. Or in the "race mode", pace management functions such as timer, and distance compensating tripmeter.

•YZ250F inspired body work. This "slim line" bodywork allows fast, easy rider movements and a lighter overall machine feel.

•Stylish slim design headlight offers 35 watts of lighting power. The headlight beam is adjustable up and down.

•Slim design compact LED taillight is tucked out of the way to prevent damage

•7.5 litre black plastic fuel tank is designed to allow easy rider movements. The tank features a special "fluorination surface treatment" which reduces fuel permeation for improved environmental protection.

•Lightweight aluminum kickstand is designed to allow lots of Ground Clearance.

•Heavy duty one piece resin plastic engine guard. Only 3 bolts hold it in place for easy removal when washing the bike.

•Extra wide 55mm stainless steel foot pegs provide excellent grip.

Additional Features:

•Low fuel warning light on main on / off ignition switch

•Tapered steering head bearings for durability

•Serrated rear brake lever and folding shift lever tip

•Rugged, plastic, lower rear disc and rear caliper protectors

•Sealed, low-maintenance battery is gel-filled type to prevent leaks in the event of a tip-over.

•Waterproof starter button and engine kill switch are handlebar-mounted.

•Lightweight chain guide / support helps reduce chance of chain derailment. Also helps protect rear sprocket damage too.

•Heavy duty "O" ring chain for durability

Review

Yamaha certainly pushed me out of my comfort zone last week at the launch of their new WR450F in spectacular mountainous territory around Dorrigo (NSW). Enduro bike tour company, Coffs Harbour Detour, were tasked with setting the course, and it was a doozy.

A lot of the terrain is regularly covered with their tour groups, but due to the level of riders on our launch quite a few ‘special test’ style sections were added in to satisfy the Pro level riders amongst us. Riders present included; Finke Desert Race winners, a NZ Hare Scrambles Champ who surely is the result of some Kiwi microbiology experiment fusing mountain goat DNA with that of a human, and dirtbike legend Stephen Gall who seemingly floats on a higher plane above the machine and controls it by telepathy rather than human movements; demonstrating the effortless grace and perfect technique that enabled him to rule Australian motocross tracks for so long, and coach virtually every top Australian rider in recent times.

I was more than a little out of place amongst such greatness. Devoid of fitness or talent I nonetheless muddled through and ‘eventually’ conquered every obstacle in my path, largely thanks to the brilliance of the new Yamaha.

After two days of riding together I questioned Boris and Luke from Coffs Harbour Detour Tours about the general level of skill among their regular clientele in comparison to mine. They noted my level was about the same as their average customer, who generally would not be taken on a few of the more testing tracks we traversed, but is exactly the target market for the new WR450F. Thus my feedback is likely to be more relevant with what those at that average level of enduro bike experience. We may stick mcnews.com.au resident fast gun Mark Willis on a WR for more pro level feedback at a later date.

Experts chose a hard hitting map for much of the route, (a level of tune I also sampled for the grass track loop and much of the first day’s challenges) I, wisely opted for a softer map for the rigours of day two due to the slipperier nature of the surfaces and the more extreme ascent and descent gradients encountered. Mapping changes done in a matter of seconds via a hand-held tuning unit renders old style clip, needle and jet fettling to the dark ages. Good riddance I say.

There is nothing quite as exhilarating as a finely tuned flat-slide carburettor when on the gas, but in every throttle opening, except wide open, the latest electronic trickery wins hands down. On the WR450F a manual adjustment is still provided for the idle - which I adjusted a couple of times before finding the sweet spot as the engine loosened up - and like the mapping, is easily adjustable for rider preference and the conditions.

The fuel injection system provides crisp fuelling with a smooth pick-up from closed throttle. This particular Yamaha system, first introduced on the YZ450F last year before graduating to the WR450F for 2012, is absolutely ace - I couldn’t fault it. Smooth off the bottom to help find the elusive last skerrick of traction where there is none, it builds into a wide torque-laden mid-range with added pep up top, and graced with a generous amount of over-rev it was simply flawless. Effortless starting is provided via button with the trusty back-up kick-starter provided should your battery go flat. The machine can also be used without a battery should you want to save weight, thanks to a larger magneto fitted to power the fuel pump and EFI system.

The first time I thought of the clutch was at the post ride debrief when filling out a questionnaire on the bike for Yamaha Japan WR450F project leader Masaki Kamimura, who also rode with us on the first day of testing. It was only then that I remembered just how faultless the take up and engagement of the clutch had been throughout the ride. The clutch allows for effortless restarts halfway up snotty hills even after looping out. The gearbox was also fuss free with engagement very positive and false neutrals rare. Likewise the braking performance was predictable with good feel at the lever.

The superb chassis was developed in conjunction with the nimble YZ250F motocross machine and is graced with vastly improved new 48mm twin-chamber forks and a well damped shock, making the new WR450F a class package.

Despite my, ahem, widening girth, the new forks worked brilliantly and shrugged off the worst of my timing mistakes over obstacles, and with the shock preload wound on to provide 90mm of sag it was easy to keep the front planted when required.

The nimble steering geometry allowed me to easily change my line of attack on rutted sections while retaining enough stability to prevent me darting all over the track as I strayed over odd shaped rocks, or slipped over gnarly tree roots that were seeking to bring me undone. Due to my well-honed sense of self-preservation and caution, deflection is one trait I can’t abide on the trail. Thankfully the WR450F was rock-solid in the stability stakes at low speeds. Over the two days, only one brief section of track saw higher speeds reached, thus I can’t make a definitive call on the stability of the WR450F at speed, but certainly encountered nothing to suggest that this might be a problem. I would expect wide-open desert racers to fit a steering damper as a matter of course.

The standard foot pegs offered great purchase for my boots and the long, slim seat worked well ergonomically. I am not a doyen of body positioning by any means, but I never felt in the least bit restricted and never heard any complaints from the more animated riders amongst us.

Shorter riders will rejoice loudly at a welcome feature of the new WR450F. Seat height has been lowered to 960mm as a consequence of Ground Clearance being reduced to 335mm. I never bottomed out either end of the machine and only once struck the lower frame rails while making a judgement error negotiating a downed tree. At a short legged 178cm, I found the reduced reach to the ground, for a quick dab of the boot to regain front traction, quite reassuring.. The reach to the bars is also 10mm shorter.

Reliability was also a high priority for Yamaha engineers. Larger radiators, wider big-end bearings to cope with the low speed chug loads made possible by EFI, a piston oil-jet sprayer to help cylinder cooling and a myriad of other changes were introduced to improve serviceability. The dry sump engine retains the five-valve layout of the previous WR450F, a top-end design with an unparalled record of reliability in recent years. This record will help endow confidence in prospective purchasers, a very important point in the world of high-performance enduro machines in regard to ongoing ownership costs and an area where Yamaha has the runs on the board.

The standard machine ships with Bridgestone Gritty rubber. Our launch bikes were fitted with a Dunlop D952 rear hoop and a Metzeler Six Days Extreme up front, a combination that worked extremely well across all surfaces encountered.

The only thing the WR450F did wrong during my time with it was to sometimes take a few stabs of the starter button to fire, and a muffler bolt worked loose on another machine. The lack of any ignition key or physical security demands that a cable lock be carried for overnight stops.

Dynamically the only slight flaw I found was that, despite the agile handling and slim profile, the WR felt a little heftier than would be preferred. While no scales were present at the launch, Yamaha staff claimed the machine is 114kg dry in enduro trim with ADR road gear removed, or 129kg with its 7.2 litre fuel cell full and all ADR accessories in place.

The modest 7.2 litre fuel cell is a restriction for many but Yamaha are only weeks away from introducing an optional larger main tank and auxiliary rear tanks for more long-distance adventures. A warning light on the instrumentation illuminates when two liters are remaining in the standard tank. Obviously standard range is largely decided by your wrist, and we didn’t run the machines dry, but guesstimates are: an average 100km range; reducing to 80km for fast aggressive riding; or extending perhaps as far as 120km in more moderate use.

Clearly, the WR450F is no lightweight motocross machine, nor is it designed to be, but for most weekend warriors and enduro riders the WR will pose no problems and will be forgiven if the new WR450F lives up to the rugged reputation earned by its recent predecessors.

The expected reliability along with the tractable engine and excellent suspension make the $12,999 WR450F my preferred option in the big-bore enduro market. Incorporated in that price is a competition kit valued at $650 inclusive of a new front master cylinder, braided brake line, handguards, GYTR muffler tip, LED tail light and plate holder, brake snake, 13/50 sprocket set and wiring for the optional ($399) power tuner.

- Pictorial - Yamaha WR450F Image Gallery

+ Positives
- Smooth tractable engine
- Easy EFI tuning
- Throttle response
- Excellent suspension

- Negatives
- A little heavier than ideal
- No security
- Three month parts only warranty par for the course in this segment but still not generous enough

Source mcnews.com.au