MXA RACE TEST: The New 2009 Husaberg FE450; Suspension Settings, Jetting Specs, Likes & Dislikes, Plus Much More About The Unusual Upside-Down Engine

On Jun 8, 2009 Last updated Feb 24, 2018

MXA RACE TEST
INSIDE THE 2009 HUSABERG FE450

ÿÿ Of all the motorcycle manufacturers in 2009, perhaps the one with the least effective American marketing is the Husaberg FE450. There are two reasons for this:

ÿÿ 1. Limited edition: Even in the best of times, Husaberg has never been a big player in the American market. And with a $9500 price tag, it never will be. Husaberg doesn’t run fancy color ads or spend millions on professional racers because they believe that if you want an FE450, you’ll find one. Husaberg claims that it brings in 1000 units a year?-we think that is an optimistic number.

ÿÿ 2. Stalking horse: KTM owns Husaberg, and while it may not be 100 percent correct to say that KTM doesn’t care if Husaberg sells any bikes in America, it is accurate to say that Husaberg is a stalking horse for KTM. What does that mean? KTM’s investment in Husaberg isn’t because of their giant sales numbers or ability to stand on their own in the marketplace. No, KTM bought Husaberg as a proving ground for new ideas. It is the “Let Mikey do it” approach to R&D. Husaberg can experiment with new ideas without any market pressure, and the ideas can be transferred to KTM once they are proven.

ÿÿ And, as stalking horses go, the 2009 Husaberg FE450 is amazing. It bristles like a porcupine of innovation. It is the first offroad bike to have closed-loop fuel injection, an all-plastic subframe, an upside-down engine, stacked transmission and maximized centralization of mass.
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Q: WHO CAME UP WITH THE IDEA OF AN UPSIDE-DOWN ENGINE?

A: Husaberg engine designer Jens Elmwall is the man behind the unique design. “I have always been jealous of the two-stroke’s agility when compared to a four-stroke. The crankshaft of an internal combustion engine spins at very high speeds, which in turn creates gyroscopic forces that affect the motorcycle’s handling negatively, especially when cornering. The two-stroke is much lighter and quicker when compared to a four-stroke. I wanted to find a way to make a four-stroke handle like a two-stroke.”

ÿÿ Then, one day back in 2003, Elmwall had an idea. Why not move the rotating mass as close to the motorcycle’s center of gravity as possible? Jens and fellow designer Roland Ohrn went to the Husaberg R&D department and cut two engines apart to build a rough version of Jens’ idea. Then they wedged it into an existing Husaberg chassis.

Q: WHAT IS THE MAIN THEME OF THE UNUSUAL ENGINE DESIGN?

A: Let us take you back to Mr. Wellman’s high-school physics class: By raising the crankshaft up 100mm, moving it back 160mm and putting the gearbox beneath the cylinder, rather then behind it, the rotating masses of the crankshaft, piston and valve train are placed closer to the bike’s center of gravity. With the rotating mass closer to the center of gravity, the torque effect on the chassis is greatly reduced. In layman’s terms, they’ve put the part of the engine that wreaks havoc on handling as close as they can to the place where it will have the least effect on handling. Simple, but clever. Clever, but unproven.

Q: WHAT ARE THE FE450’S PERTINENT ENGINE SPECS?

A: Although it is often referred to as an upside-down (or slant engine) design because of its 70-degree cylinder angle, the Husaberg engine is a fairly conventional design (try to envision a conventional engine turned around backwards and then flipped forward 90-degrees).

ÿÿ The 449.3cc engine has a bore and stroke of 95mm by 63.4 mm. The compression ratio is a mild 11.8:1. The transmission has six-speeds, and the starter system is electric. For riders who want more power and torque, Husaberg makes a 565.5cc version of the upside-down engine. It has a 100mm by 72mm bore and stroke. In the past, Husaberg offered three displacements of their previous engine design, but for 2009 only the 450 and 570 are offered.

Q: HOW DOES HUSABERG GET LUBRICATION TO THE UPSIDE-DOWN ENGINE?

A: Even though the engine is upside down, the lubrication system is no different from any modern four-stroke’s. The oil circulates via pressure pumps that supply lubricating oil to the crankshaft, piston, clutch, transmission and valve train. In addition, a special suction pump scavenges excess oil out of the cylinder head and reroutes it back to the transmission.

Q: IS IT SWEDISH OR AUSTRIAN? A KTM OR A HUSABERG?

A: Make no mistake about it, the Husaberg FE450 is a KTM (but don’t tell that to the Swedes). Husaberg was started in 1988 (at an inauspicious press intro where their first engine blew apart). The Swedes are very proud of their motorcycle heritage, and the Husaberg FE450’s creative engine was designed and prototyped in Sweden, but the finish work was moved to Austria. Husaberg is to KTM what Lexus is to Toyota.

ÿÿ And, since virtually every baseline part of the Husaberg is borrowed, in one form or another, from KTM, it quickly becomes obvious that, with the exception of the kernel?this is KTM’s popcorn. Even more telling, if it works it will be transferred to future KTMs.

Q: DOES THE HUSABERG FE450 HAVE A CARB OR EFI?

A: Given the 70-degree layout of the cylinder, carburetion would have presented some serious space issues. The FE450 is fueled by a 42mm, downdraft, Keihin electronic fuel injector. It should be noted that Husaberg uses a much more sophisticated closed-loop management system for its fuel injection compared to Honda, Suzuki and Kawasaki’s open-loop system.

Q: WHAT IS AN OPEN-LOOP FUEL INJECTION SYSTEM?

A: On the first generation of fuel-injected motocross bikes, carburetors were replaced with throttle body fuel injection systems that were just slapped in the place where the carb was mounted the year before. In sticking with their bolt-on simplicity, the RM-Z450, CRF450 and KX450F fuel-injection systems use an open-loop management system. The open-loop fuel-injection system uses a small number of sensors to determine a small number of possible fuel programs. A main characteristic of any open-loop controller is that it does not depend on feedback to determine if its output has achieved the desired goal.

ÿÿ The Husaberg FE450 does not use an open-loop fuel management system. It uses the more advanced closed-loop system.

Q: WHAT IS A CLOSED-LOOP FUEL INJECTION SYSTEM?

A: Closed-loop fuel injection systems use all of the sensors that an open-loop system has, but manage the air/fuel mixture with an exhaust gas/oxygen/lambda sensor. The O2 sensor is mounted in the exhaust system and enables the engine management computer (ECU) to determine and adjust the air/fuel ratio precisely and quickly. A closed-loop system provides more accurate fuel metering and quicker real-time response.

ÿÿ Not only does Husaberg have the only closed-loop fuel management system of the Big Five, but it comes with three preprogrammed maps that allow the rider to adjust the ignition curve without having to hook up a laptop computer. There is a soft timing/ignition/fuel curve, a standard one and an aggressive one. The three preprogrammed maps are activated by plugging the ECU leads into numbered ports. Standard map is unplugged, soft is plugged into number one and aggressive is plugged into number three.

Q: WHAT KIND OF SENSORS DOES THE FE450 HAVE?

A: Because it is a closed-loop system, it has more sensors than an open-loop system. The FE450 has seven sensors: air density, water temperature, throttle position sensor, tip-over (activated at 65 degrees), manifold pressure, lambda (oxygen sensor) and intake air temperature. The typical fuel-injected Japanese-built motocrosser has five sensors.

Q: WHAT DOES THE HUSABERG USE FOR FORKS?

A: Since KTM owns both Husaberg and WP, there is an inevitable swap of technology from Holland to Austria to Sweden. The FE450’s 48mm WP forks mimic the forks on the KTM EX-W enduro bikes?although they seem to be much softer.

Q: WHAT DOES THE HUSABERG USE FOR A SHOCK?

A: Jens Elmwall was an engine designer. His main interest in life was seeing his unique engine configuration in action. He didn’t care much about the chassis. This is made all the more evident by the rear shock. You don’t need much imagination to see that the Husaberg’s rear suspension is KTM’s rear suspension (same rising rate)…moved and hidden behind the monocoque subframe. One note of caution: to change the preload on the FE450’s rear shock, you have to remove it from the bike (luckily the no-link rear suspension comes off with only two bolts).

ÿÿ You cannot use the shock off a KTM on a Husaberg (although they are virtually identical in design, spring rate, valving and length). The piggyback body on the Husaberg shock is oriented differently and a KTM piggyback will hit the gas tank.

Q: WHERE IS THE AIRBOX?

A: It is where you think the gas tank should be. The air filter is located directly behind Husaberg’s remote gas cap and uses the seat as an airbox cover. This is a very cool location. It is easily accessed by removing the seat (which has a rip-cord-style cable release system). And, given the down draft EFI system, it really couldn’t be anywhere else.

Q: WHERE IS THE HUSABERG GAS TANK?

A: Since the air filter is where the gas tank is normally found, the fuel tank is logically placed where the airbox would typically be. In truth, the 2.2 gallon gas tank is everywhere, as it fans out across the frame and under the seat. Because of its low center of gravity, this gas tank would have trouble providing fuel on a carbureted bike, but thanks to the fuel-injector’s fuel pump, fuel delivery is no problem. The gas tank is vaguely translucent to make checking the fuel level easier (but it isn’t easy).

Q: WHAT’S WITH THE PLASTIC SUBFRAME?

A: The Husaberg does not have a conventional, aluminum-tube subframe. Instead it uses a monocoque cross-linked polyethylene plastic structure to do the job of a metal subframe. From an engineering and innovation point of view this seems very trick, but it is really stupid. It is ungainly, bulky, blocks access to the shock and, even with molded-in handholds (which are too far forward to be of any use), it adds nothing to the Husaberg?apart from buzz at the yearly plastics convention.

Q: IS THE FRAME STEEL OR ALUMINUM?

A: The double-cradle perimeter frame is built from ovalized chromoly steel. Although it is not a KTM frame, it does borrow KTM’s tubing, forging and basic layout. The KTM frame parts lead directly to a KTM swingarm.

Q: WHAT OTHER PARTS ARE BORROWED FROM KTM?

A: The brakes, wheels, transmission gears, cylinder, radiators, electric starter, triple clamps, handlebars, gas cap, muffler, levers, piston, gaskets, head (although it has a different oil pickup location), crank, counterbalancer and hydraulic clutch. The only engine parts that are not off-the-shelf KTM items are the cases, covers and cam.

ÿÿ The Husaberg does not use the valve-train from the latest generation KTM 450SXF, but rather from the single-overhead-cam, rocker arm-equipped 450EX-W engine. This SHOC engine is the replacement for KTM’s old RFS design. The single cam activates rocker arms that control four stainless-steel valves.

Q: WHAT IS THE EXHAUST PIPE MADE FROM?

A: Stainless steel. Its routing is so unique that it is virtually impossible to damage the head pipe or midpipe in a crash.

Q: DOES THE 2009 HUSABERG FE450 USE THE SAME BRAKES AS KTM?

A: Yes?the good ones. The front Brembo is directly off the 2009 motocross bikes. This is a super brake.

Q: HOW MUCH DOES THE HUSABERG WEIGH?
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A: It is heavy for a motocross bike, but the Husaberg FE450 isn’t a motocross bike. It is an enduro bike. As it sits, it weighs exactly the same as its main competition, the KTM 450EX-W, at 250 pounds. That is 15 pounds more than the comparable KTM 450SXF motocross bike.

Q: HOW MUCH DOES IT COST?

A: $9499. For comparison, the suggested retail price of the YZ450F is $7399, KX450F $7549, KTM 450SXF $7998, RM-Z450 $7499 and CRF450 $7599.

Q: WHAT IS IT LIKE TO RIDE THE HUSABERG FE450?

A: Interesting, to say the least. First and foremost, this is not a motocross bike and no one will buy this bike to race motocross. If they did, they would be very unhappy. All that said, the MXA wrecking crew did race the 2009 Husaberg FE450, and we want to be sure that everyone understands that our assessment of this bike is based on our decision to use it for something it was not designed for.

ÿÿ There is no doubt that Jens Elmwall is creative, but when you mix creativity with mediocrity, the result is no longer Mensa material. The Husaberg may well be very light in yaw, roll and pitch, but that fact escaped us. Elmwall’s original hypothesis is theoretically correct, but what’s the point of jerry-rigging physics to work in your favor and then putting it on a bike that weighs so much that not even plasma physics would work? We think that as a woods bike, which is what it was designed as, the FE450 would be brilliant. As a motocross bike, not so much. Although the Husaberg addresses one theoretical battleground in chassis dynamics, it ignores many others?not the least of which are precession, chassis pivot points and the negative effects of a high rotating mass.

ÿÿ In stock trim, the Husaberg doesn’t like to go fast. Its stinkbug stance, overly soft forks, radically changing head angle and heavy weight produce a bike that hunts and pecks on fast straights. Our solution was to try to bring the front and rear of the FE450 into balance. Step one was to lose the Husaberg forks and swap them for stiffer KTM forks. The stiffer forks bring the front up, lessen the rear-high stance and calm down the chassis. Step two was to set the rear shock’s preload so that we had about 110mm of race sag. This brought the rear down, lowered the ride height and required considerable clicks in on the compression damper.

ÿÿ As far as the power goes, this was a pleasant engine. Not fast, not powerful, not aggressive. It was, in a left-handed compliment way, mild mannered and easy to use. As with most fuel-injected engines, it gets its best work done early and then signs off. What power there is doesn’t go very far. Of course we have no doubt that KTM could easily make this engine produce competitive horsepower for motocross (since they build the horsepower king of the 450 class). And, Husaberg does offer a 565cc version that would eliminate any powerband doubts.

ÿÿ One of the things that should have helped the FE450’s modest powerband is the six-speed tranny. Surprisingly, it was not popular with any of our test riders. They felt like they had to pedal through the gears because of the short powerband. This setup is probably great in the woods though.

ÿÿ As you would expect from a cottage-industry design, the Husaberg is quirky. It is assumed, because of the engine configuration, that the FE450 will feel exceptionally light at speed. It doesn’t. Why not? It is impossible to trick 250 pounds into feeling light. This bike feels heavy because it is heavy (Elmwall’s parlor trick can’t escape the Earth’s gravitational pull). The biggest caveat of all is to avoid picking this bike up without wearing a Home Depot hernia belt. Sitting still, this bike defines the term “dead weight.”

ÿÿ As a test bed, the Husaberg is outfitted with as many bad ideas as good ones. We like the easy-access seat, but hate the plastic subframe. We are intrigued by the downdraft fuel injector, but find the spider-like gas tank to be irritating. We love the tucked-in exhaust pipe, but need a cutting torch to get to it. Additionally, the hand holds are useless, and the kick stand is a lethal weapon. Although it uses off-the-shelf KTM suspension components, for some reason they don’t work as well on the Husaberg as they do on the KTM. Quirky is as quirky does.

Q: DO WE THINK THAT THE UPSIDE-DOWN ENGINE HAS POTENTIAL?

A: Yes and no. As it sits in this bike, it can’t demonstrate what it is really capable of. The lightweight feel of the upside-down engine will never be felt in a heavyweight machine. Perhaps a motocross version of the upside-down engine, bolted into a true-to-life race frame, would offer sensations that most racers have only dreamed of. Other manufacturers (most notably Yamaha) will have their own spins on slant-engine design in the near future.

ÿÿ The biggest caveat is that the Husaberg FE450 isn’t a motocross bike. It is a proof-of-concept vehicle that, in our opinion, doesn’t prove anything (although it does give KTM a head start on closed-loop, fuel-injection systems).

Q: WHAT DO WE REALLY THINK?

A: We were glad to get the opportunity to race the 2009 Husaberg FE450…and equally glad to get off of it. We’ll wait for a purpose-built motocross version.