Some bikes defy being categorized. The 2021 KTM 450XC-F isn’t one of them. It’s actually a very specialized motorcycle. The confusing part is that it fits perfectly in so many categories. For one, it’s KTM’s most adept desert bike, one that has won more National Hare & Hounds than any other bike in recent history. It’s also a western grand prix racer, currently carrying the number-one plate in WORCS. And, if you look at rank-and-file racers on MX tracks across America, you’ll find it’s commonly used for motocross. If you had to come up with one label, it would be most accurate to call the 450XC-F a racer. Getting more specific can only be trouble.
We’re not sure when the title “closed-course off-road bike” came into being, but we’re finally getting used to it. Manufacturers had to come up with some kind of term to describe a bike that is intended to be used in traditional off-road events like desert races and enduros, but does not meet the government’s definition of an off-road bike. According to U.S. Customs, the Environmental Protection Agency and one particular state (you know the one), a true off-road bike must meet standards for emissions and sound. As a full-blooded racer, the 450XC-F doesn’t meet those criteria, so it exists in the ether between highly scrutinized off-roaders and totally unrestricted motocross bikes.
The KTM 450XC-F is a very close relative to the 450SX-F motocrosser. Desert guys and grand prix racers have very similar needs to those of MX racers. Performance is at the top of the list. Power, suspension and light overall weight all come into the picture, while lights, instruments and even a quiet exhaust aren’t necessarily priorities. In the case of the 450XC-F, KTM’s recipe was to start with the motocross bike and change a handful of things:
- Increased fuel capacity
- (2.25 gallons from 1.8)
- Softer suspension settings
- 18-inch rear wheel
- Dunlop AT81 tires
- O-ring chain
Features that are the same as the 2021 KTM 450SX-F start with the motor and everything in it. All the power-related components in the single-overhead-cam motor are the same and so is the five-speed gearbox. It also has the exact same muffler as the SX-F without any spark arrester or extra sound-deadening measures. For 2021, KTM came up with new mapping for the two curves embedded in the stock ECU. There’s a handlebar-mounted switch on the left that allows you to select between map one and the more aggressive map two, as well as turn traction control on or off. You can also put the bike into launch mode from the same switch, which is a feature that limits rpm until you shift to third gear or chop the throttle.
The most dramatic change for 2021 is the internal design of the WP Xact air fork. It has a new piston and what is best described as a mid-valve. It also has a neoprene bottoming cushion rather than the old hydraulic one, and a compression adjuster that requires no screwdriver. The WP is the surviving air fork simply because it was always the best one. The design is clever and simple. As the fork compresses, it reveals a passage, which has a new shape this year, that charges a balance chamber. This works in opposition to the main air chamber as the fork tops out. There’s only one air chamber that the user has to worry about. It’s in the left fork leg, and all the clickers are on the right side.
KTM also made some changes to the shock, and even though the linkage is the same, new seals offer considerably less friction. There are also valving differences between the SX-F and the XC-F.
HOW TO MAKE AN XC-F HAPPY
In the early days of the KTM XC-F models, some riders simply didn’t understand the bike. When it was sold to off-road guys who were expecting a mild-mannered, fluffy trail bike, they were in for a shock. On tight trails, they found that the power hit too hard, the suspension was too stiff, it stalled, it overheated and it had a generally grumpy disposition. Riders who understood it had no such issues. They knew it was a racer. To make the confusion worse, it was the only off-road 450 offered by KTM for a few years. If you wanted something more trail-worthy, you had to turn to the dual-sport line. As of last year, that changed. The KTM 450XCF-W was offered for the trail-riding crowd, leaving the XC-F free to be a race bike without apology.
In truth, you don’t really have to be a racer to appreciate the XC-F, but you have to have a racer’s mentality. That means you have to appreciate the fact that it’s a very powerful motorcycle. The XC-F is competitive with any motocross bike on the market, giving away nothing in sheer acceleration or top speed. By MX standards, the power is very smooth, too. In map two, it’s slightly meatier in the upper rev range, but the bike still is no beast if you are used to traditional 450 MX bikes. The beast only comes out when you find yourself in first gear in technical terrain. Even western GPs like WORCS and NGPC often have one or two sections of rocks or EnduroCross obstacles. That’s when you have to use the clutch skillfully to avoid stalling or getting in trouble, much like you would with any motocross bike. Having said that, the 450XC-F is probably more well-mannered than any other bike producing this much horsepower.
You do have the option of traction control to modify the power delivery somewhat. Don’t expect miracles here, but when you expect muddy conditions, it can be handy. You should, however, avoid it in deep sand and when you go hill-climbing with your buddies. In those situations, it deadens the power a little too much and kills revs.
Public approval of air forks is probably at an all-time low, but if any application is perfect for air, this is it. Off-road racing in the west is any suspension tuner’s worst nightmare. A desert race can have miles of wide-open whoops on the first loop and tight, rocky canyons on the second. In theory, you could adjust air pressure between loops, although you would have to have pretty good course intel ahead of time. The recommended pressure of 145 psi is a great starting place for motocross-based grand prix courses and fast desert racing. If you have time to go testing on the terrain you expect to ride, you can easily dial the XC-F’s suspension. First, just use a zip-tie on the fork leg to determine how much travel you use. Adjust the pressure until you’re using almost all the travel—leave under an inch for hard bottoms. Then use compression damping to make it more comfortable. When the XC-F is set up well, it’s superb. The changes for 2021 give it more compliance on choppiness than ever before. There are distinct improvements in the rear suspension as well. As always, it’s easier to make suspension adjustments on a motocross course than it is in off-road settings because you have a more controlled environment. Amateur MX settings aren’t that different from desert ones.
THE RIGHT PACKAGE
There’s a certain rider who is absolutely perfect for the KTM 450XC-F. Whether or not he races isn’t critical, but he likes to ride hard in open terrain and hit the occasional motocross track. Most 450XC-F riders are out west, although some of them can be found in GNCC races back east. In the final analysis, you gotta concede that horsepower is fun no matter where you ride. The KTM 450XC-F offers all you want without asking you to give up too much of what you need.