MXA RACE TEST: THE REAL TEST OF THE 2021 KTM 450XCF CROSS-COUNTRY

THE GEAR: Jersey: Alpinestars Supertech, Pants: Alpinestars Supertech, Helmet: Arai VX-Pro4, Goggles: EKS Brand Flat-out, Boots: Alpinestars Tech 10.

Q: FIRST AND FOREMOST, IS THE 2021 KTM 450XCF BETTER THAN LAST YEAR?

A: Yes. The 2021 KTM 450XCF has all of the aspects we liked about last year’s cross-country model with a few updates that make it even better. But, we have a confession to make. We didn’t ride the 2020 KTM 450XCF; we rode the 2020 Husqvarna FX450 instead. Since MXA primarily tests motocross bikes, we were happy to test just one Austrian cross-country 450 last year, and our test riders fell in love with the FX450’s ultra-smooth power curve and plush suspension. After the pleasurable experience on the Husqvarna version, we were excited to ride the 450XCF with the new 2021 WP XACT forks. 

Q: WHAT MAKES THE 2021 KTM 450XCF DIFFERENT FROM THE MOTOCROSS-SPECIFIC 450SXF?

A: The KTM 450XCF Cross-Country has a respectable list of parts that set it apart from the motocross model. Here’s a list of the differences:

(1) Oversized tank. The oversized tank carries 2.25 gallons of fuel compared to the motocross bike’s 1.9 gallons.

(2) 18-inch rear wheel. Instead of the standard 19-inch motocross rear wheel, the 450XCF has an 18-inch rim. 

(3) Suspension. The WP XACT air forks and shock have softer, cross-country-specific settings and a new lift-height component in the fork’s mid-valve, which is brand new for 2021 to increase the fork’s tuneability.

(4) Mapping. The 450XCF has cross-country-specific mapping.

(5) Hand guards. KTM’s hand guards are pretty trick. They mount directly onto the front brake and clutch perches to create more room on the handlebars.  

(6) Gearing. The 2021 KTM 450XCF shares the five-speed transmission with the 450SXF but comes with a taller 13/48 gearing ratio instead of the 13/49 you find on the 2021 450SXF.

(7) Tires. Dunlop’s AT-81 tires have an off-road-specific tread pattern, softer rubber compound and better resistance to pinch flats for riders going over sharp rocks. 

(8) Kickstand. The kickstand has a convenient rubber grommet that hangs down from the number panel to keep it from falling down while in motion. 

(9) Retail price. The 2021 KTM 450XCF retails for $10,799; $600 more than the 450SXF. 

Q: DID THE 450XCF FORKS GET THE SAME UPDATES AS THE MOTOCROSS VERSION?

A: Yes. The 450XCF got the new WP XACT air forks. They may look the same as last year on the outside, but inside they are all new for 2021. The forks have improved oil-bypass notches and a new air seal with air-bypass holes. Both “bypass” systems were developed to reduce pressure spikes and create smoother and more predictable fork action. The forks also got an enlarged cross-over bleed slot, which allows air pressure to transfer from the positive to the negative air chamber easier. The negative chamber’s main job is to stop topping out. Plus, the 2021 WP XACT forks got the same bump-stop rubber and adjustable-by-hand rebound clicker. 

The KTM 450SXF got these updates and one more; the trampoline valve. If you’re up to date on the latest air fork technology, you’ll know that the trampoline valve is located at the mid-valve shim stack, and it is another WP component that was designed to give air fork users the front-wheel traction and predictability of a well-built spring fork. The trampoline valve was added to the motocross forks but not to the cross-country forks. Instead, the 450XCF forks have a lift-height setting that allows WP to create softer suspension valving without bending shims. 

The WP XACT forks are all-new for 2021, and these forks are even different from the motocross forks, with new components at the mid-valve.

Q: WHY DOESN’T THE 450XCF HAVE A TRAMPOLINE VALVE?

A: Unless you’re a die-hard off-road KTM rider, you might not know that prior to the 2021 models, the 450XCF and FX450 didn’t have a shim stack at the mid-valve. Instead, it was only in the base valve. WP technicians weren’t able to create damping at the mid-valve on their cross-country forks because they couldn’t get the shims to be soft enough without bending or breaking shims. 

Trampoline shims are preloaded, and when oil squeezes through them, the shims can bend into the cavity (like a trampoline sinks down under force). The 450XCF float setting is similar. It uses a light spring inside of the cup-like cavity to push back up on the shims to close off the valve when switching from compression to rebound damping. This allows WP engineers to use softer shims and find their favorite off-road setting without damaging shims. 

Q: WERE LAST YEAR’S CROSS-COUNTRY-SPECIFIC XACT AIR FORKS BAD?

A: Surprisingly, no. The MXA wrecking crew thoroughly enjoyed the plush WP XACT air forks on the 2020 Husqvarna FX450; we thought they were great! But, the WP technicians assured us that from now on, the WP XACT air forks on cross-country and off-road models will be much better because they won’t be creating all of the damping at the base valve. The new lift-height spring will allow them to create damping at the mid-valve like they do on motocross models. It gives the cross-country forks a better-balanced damping system. 

Josh Fout rode MXA’s 2021 KTM 450XCF to finish first and fourth in his Vet and 450 Intermediate classes a the Lake Havasu WORCS race.

Q: HOW DOES THE 2021 KTM 450XCF HANDLE?

A: The 2021 KTM 450XCF suspension is softer initially, much softer. It doesn’t have the same hold-up strength of the 450SXF suspension, and you can feel that on the track whenever you hit a jump. On rough trails or on tracks without too many jumps, the suspension is comfortable and confidence inspiring because it soaks up the bumps without talking back. The rebound in the shock is also faster, and this helps the rear wheel stick to the ground better over chatter bumps. 

On a motocross track, the suspension is soft, but with clicker adjustments and the correct air pressure for your weight, it’s totally manageable for a day of track riding. The suspension is perfect for cross-country Grand Prix racing and desert or woods riding. Plus, KTM’s light weight benefits are just as nice off-road as they are on the track. Nimble bikes are easier to weave around rocks and trees on the trails and easier to pick up in a tip-over. Also, the added weight of a brimmed oversized tank doesn’t bother you as much as it would on a bike that starts out 10 pounds heavier than the KTM 450XCF. 

Q: HOW DOES THE 450XCF RUN ON THE TRACK?

A: On the track, the 2021 KTM 450XCF is mellow and not very exciting until you’re halfway down the straightaway where the power really shines. It rolls on without any hiccups or surges and inspires confidence in the bottom and midrange. Before you know it, you’re into the next corner. Our test riders could ride more aggressively and come out of corners with more speed, because the bike was tamer off the bottom. Weird, right? Although the bike is slower and mellower at corner exit, we were able to go faster because the power was delivered with less wheelspin and fewer unexpected wheelies.

The 450SXF motocross engine is already known for its smooth power delivery, so it wasn’t a ground-breaking discovery for us when we noticed that we could ride the cross-country version harder. KTM has been using this tactic for a few years now. Its 450 four-strokes aren’t as exciting off the bottom end and into the midrange as some potent 450 motocrossers, such as the Yamaha YZ450F or even the Suzuki RM-Z450. But, when you factor in the quieter muffler (that deceivingly makes you think you’re going slower) and the wider spread of power, you end up with faster lap times. Extra traction at the rear wheel pays dividends when looking at the stopwatch. 

Overall, the 450XCF’s power is tamer than that of the easy-to-ride 450SXF, but we appreciated that when racing at off-road Grand Prix and WORCS races, because we could ride harder and longer without getting as tired in the endurance races.

Surprisingly, the 2.25-gallon oversized tank on the 450XCF isn’t noticeable.

Q: HOW IS THE OVERSIZED TANK SO SLIM?

A: The answer is found in the geometry of the chromoly steel frame. The steel-framed Austrian bikes have a single top tube, on which the fuel tank sits and folds over both sides. In contrast, aluminum-framed bikes have perimeter frame spars that start at the footpegs and meet at the steering stem. On these bikes, the tank sits between the two frame spars. This design works fine for its intended purpose of holding the stock motocross tank, but it doesn’t leave enough room for an oversized tank without making the tank wider at your knees. If you want to add extra fuel to a perimeter frame bike, you have to go up and out. This raises the tank and its fuel cap higher and/or increases the width of the tank at the shrouds. If you’re a loyal MXA reader, you know that adding weight further away from the center of gravity equals an unbalanced chassis that’s more difficult to corner. 

In the cross-country category, the KTM 450XCF competes against its Austrian siblings (Husqvarna and GasGas), as well as the Honda CRF450RX, Kawasaki KX450X and Yamaha YZ450FX. Of these bikes, the Yamaha is the only one with the ability to add fuel without going up and out. With the backwards-engine design, Yamaha can add more capacity by making the tank go further down and further back. 

Q: WHAT DID WE HATE?

A: The hate list. 

(1) Protection. Or, should we say lack of protection. The 450XCF doesn’t come with a skid plate or any extra protection for the engine. The only guards it has are the hand guards. 

(2) Transmission. It really needs to have the wide-ratio, six-speed transmission to be an official off-road bike. Interestingly, you can buy a wide-ratio 350XCF or 500XCF, but that option isn’t available for the 450XCF. 

(3) Spark arrestor. For an extra $600, you’d expect the 450XCF to have a spark arrestor so you can go off-roading year round. 

(4) Bolts. Check the spoke nipples and rear sprocket bolts often. 

(5) Gas cap. Why? Seriously, why? KTM must have a bunch of these push-button caps left over that it needs to burn through. We hated them before and we still do.

Q: WHAT DID WE LIKE?

A: The like list. 

(1) Suspension. Unless you’re launching your 450XCF off steep jumps, the plush suspension will make you feel invincible.

(2) Powerband. The power inspired confidence, decreased our lap times and increased our ride time before we felt fatigue. 

(3) Oversized tank. The tank is slim, and it’s translucent so we can check to see how much fuel is in it at a glance. 

(4) Lock-on grips. Slightly firmer than standard glue-on grips, lock-on grips are easier and quicker to install, and slightly more durable. 

(5) Twin Air filter. KTM, Husqvarna and GasGas air boxes are incredibly easy to use. 

(6) Brembo brakes. Stopping is important when riding any terrain. Brembo brakes are second to none. 

(7) Kickstand. It’s ultra convenient to have, and the rubber grommet eliminates the worry of “what if it falls down when I’m in a corner?”

Q: WHAT DO WE REALLY THINK?

A: The 450XCF is a blast to ride, and it works well on tracks or trails. The updates made to the 2021 KTM 450XCF aren’t noticeable at first glance, but once you hit the dirt, you’ll fall in love with the updated suspension. If you’re trying to choose between a 2020 and 2021 KTM 450XCF, go for the 2021 version with the all-new forks. If you’re deciding between a 450XCF and a 450SXF, think about where you’ll be riding it most. If you’re riding trails more than half the time, we recommend the 450XCF. The only major complaint we have is its lack of a 6-speed transmission. 

Internally, the 450XCF and 450SXF engines are exactly the same, but mapping and gearing differentiate the two.

MXA’S 2021 KTM 450XCF SETUP SPECS 

This is how we set up our 2021 KTM 450XCF for racing. We offer this as a guide to help you find your own sweet spot. 

WP AIR FORK SETTINGS
As with all air forks, you need to dial in your air pressure before you play with the clickers. Remember, the air pressure is the equivalent of a coil spring. And, just as coil-spring rates are chosen on conventional forks (based on rider weight and speed), air pressure can be selected to mimic a coil spring’s rate. Ideally, your forks will end up compressing between 1 and 1-1/2 inches from the bottom of the fork leg when the pressure is correct for your weight. Wrap a zip-tie on your fork leg to figure out how low you’re going. Once the air pressure is dialed in, adjust the speed at which the forks move with the compression and rebound clickers. For hardcore racing, we recommend this fork setup for an average rider on the 2021 KTM 450XCF (stock settings are in parentheses):

Spring rate: 10.5 bar (152 psi), stock is 10.0 bar (145 psi)
Compression: 10 clicks out (8 clicks)
Rebound: 20 clicks out (18 clicks)
Fork-leg height: Second line
Notes: Be forewarned, jumping up 0.5 bar is a big difference in the forks, but we felt it was necessary to get a stronger holdup for the Grand Prix-style racing we did on this bike.

WP SHOCK SETTINGS
The shock spring on the 450SXF and 450XCF are the same, but the internal valving that allows the oil to flow through the shock on the XCF is softer. This makes for a plusher feeling over bumps, with less holdup on jumps. The rebound is also quicker for cross-country riding. For hardcore racing, we recommend this shock setup for an average rider on the 2021 KTM 450XCF (stock settings are in parentheses):
Spring rate: 45 N/mm
Race sag: 105mm
Hi-compression: 1-3/4 turns out (2 turns out)
Lo-compression: 14 clicks out
Rebound: 14 clicks out
Notes: We went in 1/4 turn on the high-speed compression to find a firmer hold up in the rear.

2021 KTM 450XCF2021 MXA bike testcross-country dirt bikeDunlop AT-81 tireshusqvarna fx450lift-height springmotocrossmxatrampoline valveworcs racingwp float vlve forksWP Xact air forks