Receiving multiple technical upgrades for 2023 to maintain its class-leading performance on the track, the FC 450 remains the pinnacle machine in the Husqvarna Motorcycles motocross line-up. A new engine not only produces a broad spread of controllable power, but positions the engine shaft arrangements at the ideal centre of gravity to vastly benefit manoeuvrability. Aiding this agile feel is the new chassis, which has been developed and manufactured using advanced engineering techniques to assist with repositioning the rotational masses to offer improved anti-squat behaviour for improved handling. Retaining the advanced electronics and high-quality components throughout, the FC 450 is finished with new functional bodywork adorned with white, yellow, and grey graphics, inspired by the Swedish heritage of the brand.
Clean, Swedish-inspired design and ergonomics are tailored to allow riders to perform at their best for extended periods of time. Adapted after countless hours of testing, the contact points and surfaces in the rider triangle have been repositioned for 2023 to improve comfort on the motorcycle. A new, flatter seat offers unrestricted movement with a high grip cover ensuring riders stay firmly in place under hard acceleration.
The proven chromium molybdenum steel frame is refined for 2023. A new shock mounting, which is no longer connected to the main tube, significantly improves the anti-squat behaviour of the chassis. With optimised wall thickness in high stress areas improving reliability, the frame continues to offer advanced geometries and flex characteristics aimed at providing unparalleled rider feedback, energy absorption, and exceptional straight-line stability. The frame is finished off in a premium metallic blue powder coating with redesigned standard frame protectors offering superior protection, durability, and grip in any condition. Additionally, the inclusion of forged brackets on the lower frame rails allows for easy installation of the skid plate, which is available as a technical accessory.
The FC 450 engine benefits from advanced engineering techniques to deliver maximum performance. For 2023 the engine is lighter, weighing just 26.8 kilograms, and is tilted two degrees backwards to further centralise mass for enhanced handling and significantly improved anti-squat behaviour from the chassis. Servicing of the FC 450 engine is made easier compared to previous models thanks to the addition of service markers on the engine cases.
The 48 mm split air forks now offer improved bottoming resistance thanks to a new hydrostop, which applies a progressive damping force in the last 40 mm of travel for even greater comfort. The WP forks are designed with a capsulated, adjustable air spring and pressurized oil chamber for smooth action and consistent damping. Oil and air bypasses reduce pressure peaks and in combination with a midvalve damping system, the forks provide precise feedback to the rider. The settings are easily adjusted via the single air pressure pre-load valve, as well as through easy access click adjusters for compression and rebound. For improved durability, new fork protection rings prevent dirt intrusion. Additionally, the air pump needed to adjust the fork's air pressure is provided as standard.
An all-new design results in a 15 mm shorter rear shock, which is 100 g lighter compared to the previous generation while the rear wheel travel is set at 293 mm. Inside the shock is a Computational Fluid Dynamics (CFD) optimised main piston for improved initial comfort which provides strong hold-up in all conditions. Different sized holes in the shims allow them to open more easily which reduces the overall stress of the oil flow. Complete with low friction SKF seals and a revised linkage system, consistent damping, comfort, and traction are guaranteed with rebound and both high and low speed compression now adjustable by hand.
The redesigned SOHC cylinder head is incredibly compact with the camshaft positioned as close to the centre of gravity as possible for significantly improved handling and agility. A new, more durable fine punched cam chain runs on low-friction chain guides for optimal efficiency and improved reliability with a single oil spray jet guaranteeing effective cooling. The lightweight valves are actuated via a rocker arm and feature timing specifically designed to deliver precise levels of torque and throttle response.
Cylinder and piston
The lightweight aluminium cylinder is undoubtedly an engineering masterpiece and features a 95 mm bore with a 63.4 mm stroke. Inside, the CP bridged-box-type piston features anodised annular grooves, adding durability and longer service intervals at a weight of just 327 g. For improved performance, the compression ratio has been increased to 13.1:1 to create an incredible peak power to ensure the FC 450 remains firmly at the front of the pack.
The crankshaft is specifically positioned to harness the rotating mass in the ideal centre of gravity resulting in a lightweight and agile handling feel. As such, the inertia produced by the crankshaft is carefully calculated to deliver optimal traction and rideability from the powerful 450cc plant. A plain big end bearing comprising of two force-fitted bearing shells ensure maximum reliability and durability, guaranteeing long service intervals of 90 hours.
Designed for optimised mass centralisation, the FC 450 crankcases arrange the shafts and engine internals in the perfect position to achieve the best possible handling. Manufactured using a high-pressure die-cast production process, the result is a thin, exceptionally strong wall thickness at the lowest possible weight.
The FC 450 features a Dampened Diaphragm Steel clutch, which includes a single-diaphragm steel pressure plate instead of traditional coil springs. It integrates a damping system for better traction and durability. The clutch basket is a single-piece CNC-machined steel component, which has been revised to accommodate the new gearbox in 2023, and continues to allow the use of thin steel liners that contribute to the compact design of the engine.
Produced by Pankl Racing Systems, the 5-speed gearbox is designed to be extremely light and durable while featuring optimised and proven motocross-specific gear ratios (29:72). A redesign of the shift shaft reduces the operating forces required for gear changes. Integrated into the shift drum, a new quickshift sensor can be activated by pressing the QS marked button on the Map Select Switch to further aid seamless upshifting.
Polyamide-reinforced aluminium subframe
Made from 60% polyamide and 40% aluminium, the new two-piece subframe for 2023 ensures exceptional strength and durability at an overall weight of just 1.8 kg. The lower subframe spars and frame mounts are manufactured from cast aluminium for significantly improved reliability. The upper section of the subframe is made from injection-moulded polyamide to enable specific flex characteristics and ensure a lightweight construction.
CNC machined triple clamps
Matching the new frame design and suspension set-up, the CNC-machined triple clamps provide precisely calculated geometry for increased stability. Customised handlebar flex can be achieved by the new handlebar clamp which offers two mounting options – rubber-damped for less vibration or fixed for enhanced front-end feedback. The upper triple clamp is stiffer to ensure a smoother fork action and plays a vital role in the perfect alignment of the front wheel for superior handling.
The new hollow die-cast aluminium swingarm is manufactured from a single piece of aluminium using an improved die-cast production process for optimal stiffness and a 190 g weight reduction over previous versions. In order to optimise and match the flex characteristics from the new frame, a new 22 mm rear axle is fitted. Additionally, the chain guard and chain slider have been completely redesigned for improved durability and are less prone to hooking on external objects.
Designed with precisely positioned inlet ducts aimed at reducing drag and air flow deformation, the airbox ensures unrestricted airflow with maximum filter protection. The TWIN AIR filter is easily accessed without tools, by simply removing the left side panel for easy maintenance. Offering further performance customisation, the FC 450 is delivered with an additional airbox cover that can be changed without the use of any tools for a sharper throttle response according to rider preference or track conditions.
The high-performance Brembo hydraulic clutch system guarantees even wear, near maintenance-free operation and perfect modulation in every condition. Meaning that play is constantly compensated so that the pressure point, and function of the clutch remain identical in cold or hot conditions, as well as over time. Countless hours of race-focused testing have proven the high-quality, Italian-made Brembo hydraulic systems’ exceptional reliability.
The highest level of quality is guaranteed with class-leading Brembo callipers made from single pieces of aluminium for strength at the lowest possible weight. Together with a redesigned 260 mm front and a 220 mm rear disc which offer improved dirt removal, superior stopping power and braking confidence is guaranteed in all conditions.
Developed between Husqvarna Motorcycles and leading handlebar manufacturer, ProTaper, the exclusive bend offers superior comfort, class-leading strength, and fatigue resistance at the lowest possible weight.
ODI lock-on grips feature an innovative integrated throttle mechanism and a glue-free installation. The throttle assembly offers easy free-play adjustment with the option to fit alternative cams for a personalised throttle action.
All-new, CFD-designed footrests offer a 26.8% larger contact area to ensure better control of the machine while being less susceptible to hooking on deep ruts, take-offs when scrubbing, or trackside barriers. This was achieved by a new, narrower mounting design in the frame layout, which also helps reduce overall weight.
Wheels and tyres
Assembled with CNC-machined hubs, strong spokes, and black-anodised alloy rims by D.I.D, the wheels of the FC 450 are fitted with DUNLOP GEOMAX MX33 Motocross tyres which feature a proven block-within-a-block design for more progressive cornering and superior grip. For increased traction and stability through ruts, the FC 450 is fitted with a 120/90-19 rear tyre while a 80/100-21 front tyre ensures optimal grip on a variety of riding surfaces.
The exhaust system on the FC 450 features a flow-designed resonance chamber, which plays a vital role in delivering class-leading performance. Manufactured in two pieces and designed to be as compact as possible, the header pipe allows for the system to be removed without removing the rear shock. The silencer has a short and efficient design, moving weight closer to the centre of gravity and ensuring impressive power while keeping noise as low as possible. A black coating highlights its premium quality.
Manufactured from high-strength aluminium, the radiators are designed using Computational Fluid Dynamics (CFD) to channel air in the most effective way. A large centre tube channels coolant through the frame to reduce pressure at this point in the system for a more consistent flow while a new internal thermostat further enhances reliability.
A new and bigger 7.2 litre fuel tank integrates neatly into the revised bodywork. Due to the new fuel pump design and position, the tank is emptied further for increased running times. For improved safety, the external fuel line is specifically routed to make it less exposed and susceptible to damage.
Map select switch
A redesigned and intuitive handlebar-mounted map select switch allows riders to activate launch and traction control, enable the new quickshift functionality, and allows riders to toggle between two engine maps. The easy-to-operate map select switch allows racers to quickly alter and set up the engine characteristics on a race by race basis dependent on track conditions and rider preference.
The new quickshift function can be activated or deactivated via the map select switch. The function works only when upshifting, interrupting the ignition for a fraction of a second. This allows upshifting while the throttle is fully open without the use of the clutch. A sensor on the shift drum registers the force from the shift lever, sends the signal to the ECU and the ignition timing is interrupted. To prevent unintended shifts and false neutrals, the function is only active from second gear upwards.
Traction control on the FC 450 is engaged by a button marked ‘TC’ on the Map Select Switch and functions by analysing throttle input from the rider and the rate at which engine RPM increases. If the RPM increases too quickly, the Engine Management System (EMS) registers a loss of grip and reduces the amount of power to the rear wheel to ensure maximum traction. This is a distinct advantage in wet or muddy conditions.
With the engine at idle, launch control is engaged by pressing the traction control and quickshift buttons simultaneously. Both symbols will start flashing to indicate the launch control is active. This function limits the amount of power to the rear wheel, improving traction, and preventing loss of control under hard acceleration. Once a gear change is made, the launch control will deactivate automatically. Additionally, the quickshift function is deactivated while launch control mode is engaged.
For personalised power delivery, the FC 450 has two built-in engine maps as standard. Map 1 offers linear, predictable power, while Map 2 is more aggressive for a sharper throttle response and more explosive power output.
The new Engine Management System (EMS) is designed to be smaller and lighter while being faster at processing data. It incorporates a new rollover sensor (ROS) which cuts the ignition and shuts off the engine for safety in the event of a severe crash, adding another level of safety to Husqvarna Motorcycles’ new generation motocross line-up.
A new hour meter comes with an integrated fuel level indicator, which is visible on the FI status LED, indicating to the rider when the fuel level is becoming low.
The new combined start/stop switch is located on the right side of the handlebar for easy, thumb-operated use. Not only simplifying the starting and stopping of the engine, the removal of a designated stop only button from the handlebar reduces the risk of potential damage or activation in the event of a fall.
Along with the benefit of an easy electric starting system, a lightweight Li-Ion 2.0 Ah battery is fitted to the FC 450. The Li-Ion battery weighs approx. 1 kg less than a conventional lead battery meaning the convenience of electric starting is delivered while keeping overall weight to a minimum.
|Design||1-cylinder, 4-stroke engine|
|Clutch||Wet, DDS wet multi-disc clutch, Brembo hydraulics|
|Primary Drive||X-Ring 5/8 x 1/4"|
|Frame Design||Central double-cradle-type 25CrMo4 steel|
|Front Suspension||WP XACT-USD, Ø 48 mm|
|Rear Suspension||WP XACT Monoshock with linkage|
|Front Brake||260 mm Disc brake|
|Rear Brake||220 mm Disc brake|
|Ground Clearance||336 mm|
|Seat Height||939 mm|