2021 Yamaha WR450F Review (18 Fast Facts From the Trail)

August 17, 2021

The 2021 Yamaha WR450F represents a rethinking of its placement in the marketplace. No longer submitting to California’s onerous and pointless Green Sticker regulations, Yamaha has pumped up the motor and revised the chassis. The new WR450F is still quiet and has a USFS-approved spark arrester, so it’s United States Forestry Service friendly, making it an ideal trailbike. While there’s a racer’s heart beating underneath the civilized exterior just waiting for appropriate mods, we tested it in stock condition for non-competitive off-road riding.

Yamaha worked over the WR450F powerplant for 2021, and not without a significant result. It gets more aggressive cam profiles directing valves at a steeper angle, plus a higher compression piston and longer connecting rod. The headpipe connector and the air filter are flowing more air. Although all of this is bad news for Californians— they voted for the people behind the rules—Yamaha traded Green Sticker compliance for increased performance a few years ago, and Yamaha doesn’t appear to be going back.
The 2021 Yamaha WR450F’s motor has a triple personality—all of them are enjoyable. The results of the rethinking of the WR450 powerplant are inescapable. The motor has an ultra-wide usable powerband from about 2500 to 11,000 rpm. However, the power isn’t delivered linearly, so it’s a matter of deciding which part of the rev range suits what you want to do.

In the lower rev range, the WR450F is happily docile. From idle to about 5000 rpm, the DOHC motor puts out torquey power that makes quick work of the most technical trails. Nothing happens in a hurry, so you don’t have to worry about ultra-precise throttle control when you’re battling a brutal trail. The EFI fuels impeccably, so you can work through the hard stuff without worry of unexpected stalling, even at basement rpm. Throttle response is subdued, so the WR450F won’t leap out from under you without warning. It’s a sweet, torquey pleasure that invites taking on those trickier and more challenging trails that rely on your wiles rather than your wildness.

Once you hit 5k, things start to happen quickly. Give the titanium-valved motor some throttle, and acceleration happens at a much faster pace. It’s still easy to control the motor, as it’s not jumpy, but you definitely need to be paying attention. You are hurtling down the trail at a much faster pace in the midrange, and it’s a blast. While not a brutal 450-style hit, it has undeniably more muscle than a 250. It’s not just the horsepower that’s increasing at 5000 rpm—the torque is also muscling its way into the proceedings. You don’t have to be an A-class enduro rider, but this is not a portion of the powerband for beginners on a single-track.

By 8000 rpm, the gain tapers off and you are left with a magnificent overrev. The power flattens out over 8k, but don’t let that fool you. The motor is cranking out over 45 horses at this point and knocking on the door of 50 horsepower at its peak, and there’s no letting up until just before the 11k redline. It is far above my paygrade to be riding the WR450F on a woodsy single-track in this rev-range. Still, some serious hillclimbs are available with that flexible motor. On an open road or across the desert, the motor is flat-out hauling, and the bravest among us will be wishing for a sixth gear in the tranny.

A capable motor such as this requires a top-notch chassis, and Yamaha did not let us down. Yamaha reworked the flex of the twin-spar aluminum frame, along with changing the top triple-clamp, the front axle, and the engine mounts—all inspired by the YZ450F motocrosser. Without an older WR450F to compare head-to-head, all I can do is tell you that the chassis feel is flawless.

The 2021 Yamaha WR450F is absolutely comfortable changing direction on the trail. Big bore four-strokes can get demanding when the going gets tough. The front end doesn’t push or dive into corners, so its behavior is utterly predictable. The chassis and motor are both highly forgiving.

I’m big on line selection and the ability to put the motorcycle where I want it to be, and I can do that on the WR450F. The combination of the motor and the frame allows for precise handling in the woods without feeling like you’re having to wrestle an unwilling motorcycle. Although the WR450F is no lightweight at 262 pounds and the big motor can pack a strong punch, I was still able to ride it exactingly when I needed to. Even on challenging trails where a trials bike would have been more comfortable, the WR450F refused to overwhelm me. The pull from right off the bottom inspires all kinds of confidence, and the cable-pull clutch effortlessly modulates the power.

On unrestricted terrain at high speeds, the new WR450F is as stable as you can expect. The wide-ratio five-speed transmission will hurl you forward at some high speeds. I’d tell you the top speed, but the placement of the throttle cables makes it difficult to read the new LCD dash. If it’s a smooth dirt road, everything is fine. Should your riding include a good amount of high-speed riding on bumpy or rocky terrain, you’ll want to invest in a steering damper—no surprise there. Also, with all the power on tap, feel free to raise the gearing a bit for an eye-watering top speed.

When it comes time to change direction at high speeds, you can steer in a couple of ways. The front end tracks and steers well, so that’s always an option. Unless you’re tapped out, you can light up the back tire and steer with the rear with complete confidence. I never came close to losing the rear end. Sometimes the front end would push a bit—more throttle stood the chassis up, and I continued on my way.

Top-shelf KYB suspension only adds to the fun. Yamaha set up the 2021 WR450F with lighter-action suspension than the YZ450F motocrosser and YZ450FX cross-country racer. That’s exactly the right call for a trailbike. The WR450F doesn’t beat you up at all, and you have to be seriously pounding to run through the 12+ inches of suspension travel at both ends. Extra credit goes to the plus KYB Speed Sensitive Fork, which retains a plush feel at normal speeds, yet resists bottoming when you cut loose.

While the suspension is fully adjustable, I had no complaints with the stock setting when riding it in a variety of situations at a wide range of speeds. Again, this was a trail test, not a race test. I wasn’t skipping whoops or hitting huge jumps. It’s a superb setup for trail work, though I would firm things up a bit if I were using the WR450F as a desert bike where high-speed g-outs demand more bottoming resistance. On high-speed rough roads, the soft setup soaks up the irregularities without beating up the rider.

When ripping around at high speeds, you need high-quality braking, and the 2021 Yamaha WR450F delivers. Yamaha went with new pads up front and a more rigid front caliper. The results are outstanding, with the front brake having a soft enough initial bite to work well on the tightest trails, while still hauling the WR450F down from 5th gear blitzes. The rear brake is unchanged this year, and it is too touchy for low-speed work—you must rely on the excellent front brake and engine compression braking. As speeds pick up, the rear brake works better, though it still could use more feel.

The Dunlop Geomax MX33 tires work great. We tested in everything from cement-like hardpack to sand washes—sometimes just feet from each other. A soft-to-intermediate design, the MX33s did, indeed, work better in the sand washes and on loamy trails. The Block-in-Block side knobs on the rear worked especially well, helping the WR450F drive strongly out of corners. Even on the hard-pack, though, we were satisfied with the MX33s. It’s a great all-around tire, but feel free to substitute a local favorite.

The 2021 Yamaha WR450F is ergonomically neutral. There’s nothing that feels out of place, and every control is operated without undue effort. You can move around the bike easily, and get up on the tank for flat-turn cornering. The inability to read the new LCD dash while riding due to the interference of the throttle cables is a disappointment. At a stop, though, it imparts a selectable suite of information. My favorite is fuel consumption for the 2.15-gallon underseat tank—I don’t want to have to wait for the low-fuel light to pop on. The seat is correctly balanced between comfort and maneuverability.

Routine maintenance is generally straightforward. It takes no tools to get to the air filter, which lives between the fuel tank filler and the steering head. Draining the oil requires removing the welcome plastic skidplate—replacing the oil filter and oil is no problem. The mechanical muffler requires occasional cleaning and a gasket replacement, but you don’t have to mess with packing.

Although our wish-list for the WR450F is short, we have one. As wide as the 450’s powerband is, we’d still prefer a six-speed transmission. Oh, and throw in a hydraulic clutch. Also, open up the ECU to the Yamaha Power Tuner. Handguards would be nice, though we realize that Yamaha saves a few bucks by letting the buyer make the guard selection.

The 2021 Yamaha WR450F is the best of a breed that dates back to 1998. The motor is magically flexible, making the WR450F successful in a wide range of situations. Delivered in a trail bike configuration, it can easily be upgraded into a hare-and-hound demon—GNCC racers will still prefer the YZ450FX and its close-ratio gearbox. We were happy to hit our favorite trails at a fast-yet-comfortable pace on the stock WR450F, and it delivers smiles the entire time.

Photography by Kelly Callan

RIDING STYLE

Helmet: Arai VX-Pro4
Communications: Cardo Packtalk Slim
Goggles: EKS Brand
Pants, jersey + gloves: Thor Sector
Body armor: Alpinestars Bionic Pro V2
Knee braces: Alpinestars Fluid Tech Carbon
Socks: Fly Racing Knee Brace
Boots: Alpinestars Tech 7 Enduro

2021 Yamaha WR450F Specs

ENGINE

Type: Single-cylinder 4-stroke
Displacement: 449cc
Bore x stroke: 97.0 x 60.8mm
Compression ratio: 13.0:1
Valvetrain: DOHC; four titanium valves
Fueling: Mikuni EFI w/ 44mm throttle body
Transmission: Wide-ratio constant-mesh 5-speed
Clutch: Wet multiplate
Final drive: 520 O-ring chain

CHASSIS

Front suspension; travel: Fully adjustable KYB Speed-Sensitive System inverted fork; 12.2 inches
Rear suspension; travel: Linkage-assisted fully adjustable KYB piggyback reservoir shock; 12.5 inches
Rims: Excel Signature
Front wheel: 21 x 1.60
Rear wheel: 18 x 2.15
Tires: Dunlop MX33
Front tire: 80/100 x 21
Rear tire: 120/90 x 18
Front brake: 270mm disc
Rear brake: 245mm disc

DIMENSIONS and CAPACITIES