2019 KTM 450SX-F First Riding Impression

Factory Edition, Copied.

Story and Photos by Jimmy Lewis and Chris Barrett

Becoming commonplace, KTM spoils the surprise of a new model release with the well received Factory Edition a half-year previous. So we knew what was coming for 2019 at 2018.5. For KTM this is a two-fold bonus. They can race a new or improved chassis/engine at the start of each racing season and this new bike meets all of the AMA homologation requirements for pro racing and second a select few get the chance to purchase the latest and greatest, usually at a premium price. But wait a half-year, let the “I have to have it first” crowd do the final R&D and then you end up with a pretty well sorted all-new machine. Welcome to the 2019 KTM 450SX-F.
We did a one-day riding impression at Cahuilla Creek MX on the kinda-new SX to get the lowdown leading up to a comparison we have in the works. And since we missed the 2018.5 Factory Edition (read more, click here), this was going to be all new for us.

So what’s new with the 2019 compared to the 2018? The head and cylinder are new and 15mm lower by design, hence lowering the camshaft closer to the center of gravity. Surface treatments to the cam, DLC rockers and a low-friction cam chain are all working towards a goal and it isn’t just horsepower. The head also allowed KTM to further straighten out the exhaust port, which they claimed is like getting free horsepower. The transmission is now made by Pankl, along with new materials and heat treatments. Updated battery, new exhaust system, new throttle cable routing and fuel map switching. The SX-F offers two different maps as well as traction control option, making for four possible different setting. Launch control is also standard.

The ‘19 features new bodywork for a sleeker look and slimmed down radiators. The basic frame geometry and pick up points are the same but tubes have been re-worked to increase longitudinal stiffness, which makes for improved bump absorption, according to KTM. The swingarm also has a 5mm longer wheel slot for more rear wheel tuning options.

So what is it like to ride? Right away a couple of things stood out, especially to riders who have not ridden a KTM 450 for a while. It feels lighter and does not gain the weight that KTM 450s use to when you run the RPM up in the range. And it revs more free, giving the bike more “powerband” for riders. Especially those coming from 250Fs that like to spin things up. This does not mean it is going to be the lightest “feeling” 450, as it still has a bigger feel. It is lighter and smaller feeling than its predecessor. But what really gets confusing is that on paper it looks like the lightest 450 by a long shot. It also allegedly weighs in (we’d have to get it on our scale to be sure, but KTM’s numbers have been truthful lately) a few pounds down on everything else in the class. Yet when riding it, the SX-F does not act exactly this way. In fact it is claimed to be a little heavier than the older version but here it feels lighter. This shows that the numbers and the feel sometimes disregard each other.

Simply put, if feels heavier than you’d think. But there is a reason for that. The Austrian motor puts out bigger pulses of power per stroke, if we are describing the character. More of a traditional four-stroke feel. It is soft on bottom end hit, especially on map 1. But then the power builds and it builds in a progressive manner as opposed to linear, getting better and better as you get higher in the rev range. It has so much power we’d wager, without a dyno, that this is the horsepower king in the class–stock against stock. Time will tell. We were never revving the bike enough to really work the rev limiter, there was no need. Even at elevation and on a hill infested track the bike puts the power to the ground and you never feel the need to over-rev the engine.

We were split on which map we prefer, standard or aggressive, but we we aligned on not needing the traction control, which really works. It really limits wheel spin, enough that when we wanted the 450 to spin up on hard dirt before hitting the soft, it would not. The bottom on the standard map is plenty “soft” on it’s own and those that like a hit will definitely prefer the second map.
The SX-F has a bit more compression braking feel than the competition which was very connected to the idle speed. So for our rider who wanted less, we increased the idle speed ever so slightly. The hydraulic clutch is magic and the transmission, even though very new and tight, shifted just fine.

Onto the chassis and we found it to be a bit picky and more sensitive than in the past. An improvement for some, especially if you take a little time with it. It’s more nimble and agile but in a world where it typically takes two-three clicks to feel a change, one click is all you need with the ‘19. For some this will be great and for some now they will have to actually take the time to set and adjust the ride height, at least. We were right around 105mm as a starting point. It is simple to move around on the chassis and even easier to control with throttle since everything feels very connected and intertwined on this KTM. Way more than in the past. Remember the compression braking we mentioned before? Changing that really helped the turning, more so than clicks of suspension and tweaking ride height.

KTM has stayed the course with its WP AER fork, yes, an air spring fork still. They were late to the game, figured a way to make it simple, and it’s a winner in our books. KTM tuned the fork a little this year to make it feel more like a spring fork. So for most riders that will be a welcomed adjustment. It is said to be less progressive and rely more on the damping than the fork’s air pressure for the feedback a rider is getting. Hence the increased sensitivity of a single click of change. We played with pressure and clickers and found standard pressure to be spot on for our 185-200 pound testers. Then it was a matter of one or two clicks to make it personal depending on the rider. All said, we like the fork no matter how they are holding it up, don’t forget the weight advantage here. And yes, you can feel that lighter front end when riding through the handlebar.

The rear shock is a balanced match for the fork and was also on the picky side with it’s clickers. We were happy right around stock. KTM has done a good job with settings this year. One thing was apparent is that the bike nor the suspension liked if it is riding too low in the stroke. If either the rebound is too slow or the compression too soft, it lets the rider know. If the settings are out, it starts feeling like there is 18-pounds of air in the tires and the bike begins to deflect instead of absorb.

And speaking of tires, the Dunlop MX 3S was a hit or miss with our riders, especially the front. One of our riders was adamant that the bike would become much better with a different set, which goes to show how particular we can be with feeling and setting up bikes while testing. The other tester loved them and the way they slid so predictably for him. Be aware Dunlop has since updated the 3S to the new MX 33 which addresses this exact concern.

Other KTM niceties are the simple twist adjustment of lever position and engagement point, lock-on grips and very well thought out and grippy footpegs. Riders who are larger seem to easily adapt to the bike and some smaller even find it a little spread out, notably the rear brake pedal. The SX-F’s brakes are as good as they get and seem to have everyone looking for the power and feel, as well as consistency the Brembo units provide. The gripper seat really works too!

Where does this place the 2019 KTM 450SX-F? Well it is going to take a comparison to really find out, more tracks will give us a better impression of the bike’s capabilities and reveal any holdbacks. But we agreed the KTM 450SX-F is no longer an odd bike out–but rather a well rounded machine that any rider could like. We say it is picky, but without a doubt this is the best KTM 450SX we have ridden.

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