MXA RACE TEST: 15 UNDENIABLE FACTS ABOUT THE 2019-1/2 KTM 450SXF FACTORY EDITION

Given the pace of development, budget constraints and return on investment demands, KTM cannot make every Factory Edition as groundbreaking as the first one back in 2012. There are years when Roger DeCoster doesn’t need any changes for his race team and the KTM R&D department is one or two years out on the next new tech feature, so the Factory Edition just gets a bling-over. But, every three years, based on carbon-dating the eight-year history of the Factory Editions, KTM kicks out the jams and builds something special. Those models came out in 2012‑1/2, 2015‑1/2 and 2018‑1/2. Following the logical timeline, the 2019‑1/2 KTM 450SXF is not on course to feature any groundbreaking updates. That doesn’t make it a BNG bike, however. No siree. The 2019-1/2 Factory Edition gets enough technical updates to make it newsworthy.

MXA wants to reveal the changes and their effects by listing 15 undeniable facts about how the 2019-1/2 KTM 450SXF performs.

(1) Homologation. The 2019-1/2 KTM 450SXF is the 2020 KTM 450SXF disguised as a 2019 model. Back in 2012, Roger DeCoster knew that new hire Ryan Dungey needed a better bike than what was available in KTM’s 2012 inventory—and just such a bike was on the drawing boards for 2013. Roger talked KTM management into making a special run of 2013 KTM 450SXFs as 2012-1/2 Ryan Dungey Replicas. Under AMA rules, no one can race a bike that isn’t sold to the public. And, they must have at least 400 bikes available for sale to the public (this number is selected to keep the factory teams from building 10 bikes and giving all of them to the race team). KTM managed to make over 400 of the first-ever Factory Editions. And, by taking advantage of the homologation rule, Ryan Dungey got to race the 2013 KTM 450SXF in 2012.

THE PISTON AND ROCKER ARM GENERATE ROTATIONAL INERTIA THAT HAS A BIG INFLUENCE ON HOW THE ENGINE RESPONDS, AND EVEN SMALL
CHANGES CAN MAKE NOTICEABLE GAINS.

(2) Engine. On paper, there are only three changes to the 2019-1/2 Factory Edition engine compared to the 2019 production engine. First, the connecting rod, which is made by Pankl, has replaced its previous coated top-end rod bushing with a true-to-life bronze bushing (it is not brass, as brass is softer and deforms easily). Bronze bushings have replaced needle bearing-style top-end rod bearings in motorsports engines for decades because they are incredibly durable—and fail slowly instead of instantaneously like needle bearings. KTM switched to bushings instead of bearings at both ends of the connecting rod several years ago, but the bronze is a step up. Second, the CP forged piston has been reconfigured to maximize its strength with a box-shaped reinforcement under the dome. Additionally, the ring groove has been CNC-machined and hard-anodized, while the piston’s camming has been optimized to work better against the connecting rod’s thrust action. Third, the KTM 450SXF rocker arm’s architecture (topology) has been redesigned to reduce inertia on the intake and exhaust valves.

(3) Engine performance. The benefits of the three 2019 engine mods are that the power delivery feels livelier, quicker and less draggy. We don’t think that the bronze bushing contributes to this smoother power delivery, because it is mostly a durability mod; however, the change in piston camming (to lessen side thrust against the cylinder wall) and the increased stiffness and reduced inertia of the rocker arm’s topology could well contribute to improved throttle response. The piston and rocker arm generate rotational inertia that has a big influence on how the engine responds, and even small changes can make noticeable gains. Since the 2019-1/2 KTM 450SXF Factory Edition engine is the same as the 2019 production engine—save for these three small changes—we have to give a nod to the minor changes’ effects.The value added parts on the Factory Edition are the billet hubs, slotted triple clamps, new fork  valving, pleated seat cover, Akrapovic muffler, skid plate, front disc guard, stronger rocker arm, bronze top-end rod bushing, CP box piston and Red Bull team graphics.

(4) Mapping. The MXA wrecking crew didn’t like the mapping on the 2019 production engine, and we had good reason not to, since KTM’s Austrian R&D department gave us what they said was “the 2019 black box” in the middle of our 2018 450SXF test period. We loved it. It was snappier down low, moved through the low-to-mid transition with alacrity and felt stronger everywhere. Surprise! That black box did not make it onto the 2019 production bike. We were bummed, but felt sure that the 2019-1/2 450SXF Factory Edition would get it. It didn’t; however, in the middle of our 2019 450SXF test period, we tested a bevy of new factory-supplied ECU maps for the 2020 KTM 450SXF with the Austrian-based R&D department. It was very deja vu. We picked an ECU map that was much more aggressive as our favorite, but the Austrians favored a mellower map. KTM’s USA arm is now lobbying for an American-spec ECU for 2020. Let’s hope it happens.

(5) Map performance. No fear. We know a guy who can turn our 2019-1/2 Factory Edition black box into exactly what we want. Jamie Ellis of Twisted Development is a mapping genius, and the former factory mechanic will map the black box on your KTM 450SXF to the latest spec at www.td-racing.com or (951) 698-7222. In addition, we recommend drilling holes in the KTM airbox cover to help improve the throttle response from low-to-mid and to broaden the overall power. You may think that this is unnecessary, but KTM doesn’t. They plan to vent the airbox cover on the 2020 KTMs using the diamond-hole pattern from the 2010 radiator wings.

WE TESTED A BEVY OF NEW ECU MAPS FOR THE 2020 KTM 450SXF WITH THE AUSTRIAN-BASED R&D DEPARTMENT. WE PICKED AN ECU MAP THAT WAS MUCH MORE AGGRESSIVE AS OUR FAVORITE, BUT THE AUSTRIANS
FAVORED A MELLOWER MAP. 

(6) Akrapovic pipe. An Akrapovic titanium slip-on muffler comes on the 2019-1/2 KTM 450SXF Factory Edition. It is not a full Akrapovic exhaust system, just the muffler (attached to the stock KTM head pipe). We have been to this rodeo before and prefer to run the stock KTM muffler over the Akrapovic because the stock muffler hits harder and pulls quicker through the low-to-mid transition. This is where the KTM 450SXF can use the help. Bought separately, the Akrapovic slip-on muffler retails for $700.

(7) WP XACT forks. The KTM AER air forks are now labeled as XACT forks. Don’t get too excited; they are still the basic 48mm AER air forks but with damping upgrades and a new recommended air pressure setting. We asked KTM if the XACT name was an acronym for some fancy and convoluted marketing term. It isn’t an acronym; it stands for the word “exact.” WP offers three models of forks for motocross, off-road and street. They are XACT, XPLOR and APEX. There are even three versions of XACT forks: standard XACT air forks, XACT Pro Component coil spring forks and XACT Pro Component air forks. Pro Component forks are the previous Cone Valve forks.

(8) Fork performance. How do the XACT forks differ from the AER air forks on the 2019 production bike? First, the recommended air pressure has been upped from 10.5 bar (152 psi) to 10.9 bar (158 psi). This is a dead giveaway that the valving has been softened up and the added air pressure is there to hold the front end higher in its stroke longer. The 2019 production compression valve stack sat on a flat surface, which created suction against the first shim in the stack. On the XACT fork, the first shim sits on a thin pointy lip, which allows it to open sooner (thanks to less stiction). In essence, the 2019 Factory Edition forks have a bleed shim to get things in motion sooner. This is not news to KTM suspension tuners. Many of them have been taking the stock shim stacks, which start with a large 30mm shim followed by 26mm shims, and swapping the position so that the 26mm shim is at the bottom of the stack, which makes the shim stack more responsive to oil pressure. Most successful WP fork tuning focuses on the mid-valve, not the base valve.

On the track, test riders ran the compression at 12 clicks out, the rebound on 18 clicks out, and the forks slid down to the second line. The test riders’ chosen air pressure was much lower than the recommended 158 psi. The Factory Edition comes with rubber rings on each leg to allow the rider to see how much travel he is getting at a given pressure. We got our best feel when the rubber ring was within 1-1/2 inches from bottoming. With that pressure, we could use the compression damping to fine tune the travel. Overall, the 2019 Factory Edition forks, which will be the 2020 production forks, were better than the 2019 production forks.

MXA has always complained about the shape and size of the three-prong compression clicker dial on top on the left fork leg. We wanted the prongs to be longer so that they could be clicked with one gloved finger. So, WP changed them on the Factory Edition. Instead of three prongs, they now have two, but they are the same length as they were before. Oh well.

ON THE XACT FORK, THE FIRST SHIM SITS ON A THIN POINTY LIP, WHICH ALLOWS IT TO OPEN SOONER (THANKS TO LESS STICTION). IN ESSENCE, THE 2019 FACTORY EDITION FORKS HAVE A BLEED SHIM TO GET THINGS IN MOTION SOONER.

(9) KTM triple clamps. The 2019 KTM 450SXF Factory Edition comes stock with KTM’s orange anodized Factory triple clamps. These triple clamps are available separately from your local KTM dealer through the Power Parts catalog for approximately $600 (p/n 791-019990-2104). You can change the offset from the stock 22mm to 20mm by loosening the 27mm nut under the steering stem and rotating the stem 180 degrees. Less fork offset (20mm as opposed to 22mm) increases trail and, on paper, should make the bike steer slower and improve stability. We tried both and preferred 22mm offset, but test it yourself. On a historical note, this is not the first time that KTM has offered adjustable triple clamps. Back in 2005, you could change the 20mm offset to 18mm offset (and the 18mm offset was much better).

The most unique aspect of the KTM Factory triple clamps isn’t unique at all. Both the top and bottom clamps are slotted where they grip the fork legs, just like on Xtrig’s ROCS triple clamps. Instead of the fork leg sliding up into one large clamp, it slides up into two finger-like clamps with a slot between them. But, Xtrig’s and KTM’s slotted clamps aren’t exactly the same. On the Xtrig clamps, the two separate fingers of each clamping surface are held in place by opposing bolts (one on the front of the clamp and one on the back). On the KTM Factory triple clamps, both bolts and both fingers clamp on the same side (the back of the triple clamp).

BY SLOTTING THE CLAMPING SURFACE INTO TWO SEPARATE PIECES, THE FINGERS CONFORM TO THE ROUND SHAPE OF THE FORK TUBE WITH A GREATER PURCHASE AREA—THUS, THE CLAMP THAT MOST PEOPLE THINK IS MORE FLEXIBLE IS ACTUALLY STIFFER.

Now, you may think that the slotted fingers are there to make the triple clamps flex more under a load. Not so! The fingers are there to improve the interface between the triple clamp and the round fork leg. By slotting the clamping surface into two separate pieces, the fingers conform to the round shape of the fork tube with a greater purchase area—something that a large one-piece clamping surface cannot do. Thus, the clamp that most people think is more flexible is actually stiffer.

(10) WP shock. Most MXA test riders liked the overall feel of the WP rear shock, especially after they lowered the shock spring rate in 2017 from 48 N/m to 45 N/m. We aren’t the only ones who think that the KTM rear shock is in the ballpark, because there is no difference between the 2019 production shock and the Factory Edition shock. We run the low-speed compression on 15 clicks out, the high-speed compression 1-3/4 turns out (stock is 2 turns out), the rebound on 10 clicks (stock is 15 clicks out) and set the sag at 105mm.

(11) Wheels. At first glance you will think that the Factory Edition wheels are the stock KTM hubs anodized orange. We forgive you for thinking that, because that is what Factory Edition wheels have always been. Not anymore. The hubs on the Factory Edition are special. They are CNC-machined from a billet, unlike the production hubs that are cast and made to look machined. The orange anodized hubs have black D.I.D DirtStar rims laced with black spokes and gold anodized aluminum spoke nipples. Even better, the 36-spoke front wheel is laced in a cross-three pattern, which produces a much stronger hoop. Dunlop MX3S tires finish off the wheels. These wheels are available in the Power Parts catalog for around $900 a set.

THE BLUE SELLE DALLA VALLE SEAT HAS A NICE FEEL, BUT NOT EVERY TEST RIDER WAS A FAN OF THE SEVEN PLEATS THAT RAN ITS LENGTH. THE PLEATS PULL YOUR PANTS DOWN IF YOU DON’T HAVE THEM CINCHED TIGHT. 

(12) Seat. The blue Selle Dalla Valle seat has a nice feel, but not every test rider was a fan of the seven pleats that ran its length. The pleats are there to keep your butt from sliding back under acceleration. Unfortunately, they pull your pants down if you don’t have them cinched tight. Plus, if you ride cross-country races, they leave your derriere in a seriously chapped condition.

(13) Weight. The 2019 450SXF production bike hits the scales at 223 pounds. It is the lightest 450 motocross bike you can own and lighter than half of the 250 four-strokes for sale. The AMA weight limit is 220 pounds, and that is what the factory bike of Marvin Musquin weighs, but the Factory Edition’s seat cover, triple clamps, front rotor guard and skid plate add weight. Thankfully, the titanium Akrapovic muffler saves enough weight to make up the difference.

(14) Cost. The very first 2012-1/2 KTM 450SXF Factory Edition cost $9595. The retail price has gone up an average of $150 per year, which makes the 2019-1/2 KTM 450SXF cost $11,099. That makes it $1200 more expensive than the production 2019 KTM 450SXF. The cost is offset by $2400 worth of aftermarket parts—billet wheels, orange frame, holeshot device, orange sprocket, skid plate, semi-floating front brake rotor, Red Bull team graphics, D.I.D Dirt Star rims, Akrapovic muffler and a front disc guard.

THE LIST OF UPDATES AND CHANGES ON THE 2019-1/2 KTM 450SXF FACTORY EDITION ARE IMPORTANT TO A RIDER LOOKING TO PLUNK DOWN 11 GRAND, BUT THE BEST PART OF THE FACTORY EDITION IS THE THINGS THAT THE KTM ENGINEERS DIDN’T CHANGE.

(15) On the track. Obviously, the list of updates and changes on the 2019-1/2 KTM 450SXF Factory Edition are important to a rider looking to plunk down 11 grand, but the best part of the Factory Edition is the things that the KTM engineers didn’t change. Underneath the orange bling is a 450cc four-stroke motocross bike that excels in more areas than any other bike on the track. Here is the list of things that KTM didn’t change.

Brembo hydraulic clutch. This clutch is bulletproof. From it’s CNC-machined basket (with the primary gear machined into the basket) to its Bellville washer (instead of six separate coil springs) to its rubber-suspended cush inner hub to its self-adjusting Brembo hydraulics, no clutch on the track can take the kind of abuse that KTM’s can. This is the dream clutch of every clutch abuser in America.

WITH ITS “TIME-RELEASE” POWERBAND, THE 450SXF ENGINE PULLS LONGER THAN ANY ENGINE ON THE TRACK. IT IS SUPER MANAGEABLE, REGARDLESS OF WHETHER A NOVICE OR PRO IS IN THE SADDLE.

Electric starting. KTM has had electric starting on the 450SXF since 2007. That means they have 12 years of experience, which is why they can build an electric-start bike that is lighter than any kickstart model.

Traction control. KTM and Husky are the only brands with a push-button on-demand traction-control setting—and one that can be used with either the mellow or aggressive maps.

Brembo brakes. The “Big Four” Japanese brands have been throwing 270mm rotors on their old-fashioned master cylinders and calipers to try to keep KTM’s Brembo brakes in sight. They are still behind the curve.

Weight. At 223 pounds, the 2019 KTM 450SXF is 15 pounds lighter than the 2019 CRF450 and YZ450F. You may think that weight doesn’t matter, but a lighter bike’s rims, spokes, frame, shock spring, brake power and acceleration are weight sensitive. There are no factory teams that don’t believe in losing weight.

Shifting. Of all the bikes on the showroom floors in 2019, the KTM shifts the best. There are no sticking gears, false neutrals or missed upshifts. It grabs gears—and doesn’t need to be shifted as often as the average bike, thanks to the broad, linear powerband.

Powerband. With its “time-release” powerband, the KTM’s 450SXF engine pulls longer than any other engine on the track. It is super manageable regardless of whether a Novice or Pro is in the saddle. Most MXA test riders wish that it were a little stronger and quicker from low-to-mid, which is where the holes in the airbox cover and ECU mapping come in.

Handling. There are bikes that turn sharper, but they shake more or push more or stand up mid-corner or get loose on corner exit. The KTM chassis is almost telepathic. All the rider has to do is think about railing a turn and the KTM does it. It requires the least steering input of any 450 made.

What do we really think of the 2019-1/2 KTM 450SXF Factory Edition? We think that the latest KTM Factory Edition is a glimpse into the 2020 KTM 450SXF production bike. It is a harbinger of things to come. Because of this, it is best suited to rich guys, pathfinders and riders who want the latest greatest thing. There will only be 500 Factory Editions in America this year. If you must have one, you need to have your name on the list; however, for the common man, we suggest waiting a few months for the 2020 KTM 450SXF. With the money you save, you can build a race bike with the pipe, wheels, triple clamps and graphics you want—all the other good stuff will still be there.