I have been out in Clermont, Florida since last Friday spending time with Aldon Baker and the Rockstar Husqvarna team. We have been doing some training as well as some riding at Aldon’s but also got to see the reveal of the new 2022 Husqvarna FC250/450 Rockstar Editions. It has been an eye opening experience getting to train alongside the team and seeing first hand how close all of these guys really are. All of the riders on the team seem to really get along and gel well together. There will be some stories from my trip later but in the meantime feast your eyes on some of the details of the new FC250/450 Rockstar Editions. -KK
Husqvarna Motorcycles 2022 FC 250 Rockstar Edition and FC 450 Rockstar Edition
Husqvarna Motorcycles introduces the 2022 FC 250 Rockstar Edition and FC 450 Rockstar Edition models. All-new engines and chassis keep competitive motocross riders ahead of their rivals, race after race. Class-leading, dynamic performance delivers instant power, while advanced ergonomics provide complete control.
The FC 250 Rockstar Edition features a DOHC engine with unrivalled power and torque. The FC 450 Rockstar Edition has an SOHC unit, also delivering class-leading performance. Both engines are all-new, lightweight and are repositioned in their frames for optimal mass-centralization, guaranteeing easy handling and control.
The FC 250 Rockstar Edition and FC 450 Rockstar Edition also have completely revised chassis for 2022. Both bikes feature a new hydro-formed chromium molybdenum frame designed for improved anti-squat behavior under power. A new die-cast aluminum swingarm provides optimal rigidity with low weight. A durable, aluminum-polyamide hybrid subframe is designed for specifically calculated rigidity.
Suspension is by WP. New XACT 48 mm front forks with AER technology provide more progressive damping at the end of their stroke, while the latest XACT rear shock design features tool-free adjustment.
A new, multifunctional map switch selects power delivery modes. It also activates traction and launch control features, and an Easy Shift for seamless upshifts of the revised-ratio five-speed gearboxes in both the FC 250 Rockstar Edition and FC450 Rockstar Edition.
New bodywork, adorned with the latest Rockstar Energy Husqvarna Factory Racing graphics, has tailored ergonomics for ease of movement on the motorcycle. This gives riders greater control to focus on racing.
The FC 250 Rockstar Edition and FC 450 Rockstar Edition replicate the Rockstar Energy Husqvarna Factory Racing bikes competing in AMA Supercross, and offer competitive machinery to all motocross racers.
Technical highlights
ï New bodywork with specifically tailored ergonomics for easier movement on the motorcycle
ï New hydro-formed chromium molybdenum frame significantly improving anti-squat behavior
ï New topology-optimized die-cast aluminum swingarm providing optimal rigidity and low weight
ï New 250cc DOHC engine providing class-leading torque and peak power
ï New 450cc SOHC engine providing class-leading performance and low weight
ï New Easy Shift sensor providing seamless up-shifting
ï High-performance Brembo hydraulic clutch system
ï New aluminum-polyamide hybrid subframe construction providing specifically calculated rigidity and advanced durability
ï New WP XACT 48 mm front forks with AER technology offer more progressive end-of-stroke damping
ï New WP XACT rear shock design with CFD-optimized main piston and tool-free adjusters
ï New multifunctional map switch, which also activates the Easy Shift, Traction- and Launch Control
ï New Rockstar Energy Husqvarna Factory Racing graphics
ï Factory Racing CNC-machined triple clamps with adjustable offset [20 – 22 mm]
ï Factory wheel set with D.I.D DirtStar rims and black anodized CNC-machined hubs
ï New polyamide composite skid plate for advanced protection and durability
ï New polyamide composite front brake disc guard for added protection
ï Mechanical Factory holeshot device as standard
ï Soft, grey ODI lock-on grips
ï GUTS Factory high-grip seat cover
ï Premium-quality ProTaper handlebar and bar pad
ï Electric starter powered by a lightweight Li-Ion 2.0 Ah battery
Features and benefits
Frame
The hydro-formed, laser-cut and robot-welded frame is expertly crafted. Constructed with specifically calculated parameters of longitudinal and torsional flex, the frame provides exceptional rider feedback, energy absorption and straight-line stability. Additionally, the frame features forged brackets for mounting the newly designed polyamide skid plate fitted as standard on the Rockstar Editions.
Rotational masses in the frame and the forged steering head connection have been repositioned. Together with the new shock mounting, which is no longer connected to the main tube, the anti-squat of the chassis has been significantly improved. Also, the wall thickness of the frame has been optimized to achieve improved reliability and specific rigidity in high stress areas such as the steering head and the shock mounts. Parallel frame mounts (same position on left and right sides) improve chassis flex characteristics, while stability characteristics remain unrivalled.
Another highlight of the new frame topology is that the footrest mounting positions have been moved inwards, resulting in less susceptibility to hooking in deep ruts or when scrubbing jumps. The overall size of the all-new footrests has been increased, designed with the help of state-of-the-art computational fluid dynamics (CFD). The new one-piece steering head seal allows easier mounting in case of replacement or service and offers improved reliability.
The frame of the Rockstar Editions is finished off in a premium black fine-structured powder coating. The standard frame protectors feature a new and improved topology, guaranteeing superior protection, durability, and advanced grip in any condition. Mounted with four screws, using the integral frame brackets, the newly designed polyamide composite skid plate offers superior protection against dirt and hard impacts on the frame and engine.
ï Specifically engineered longitudinal rigidity → exceptional rider feedback, energy absorption and stability
ï Repositioned rotational masses and new shock mounting → significantly improved anti-squat of chassis
ï Topology-optimized frame wall thickness for specific rigidity and improved reliability in high-stress areas (e.g., steering head, shock mount)
ï New parallel frame mounts (same position on left and right side) for improved flex characteristics
ï Footrest mounting position moved inwards for reduced risk of hooking in deep ruts or when scrubbing
ï New, service friendly one-piece steering head seal → easier mounting, improved reliability
ï Durable powder coated finish with standard frame protectors and composite skid plate
Polyamide-reinforced aluminum subframe
Using 60% polyamide and 40% aluminum, the two-piece subframe has a total weight of just 3.9 lb (1.8 kg). With the help of computational dynamics, specific rigidity was engineered into the light and robust subframe, delivering outstanding handling and rider comfort.
The lower subframe spars and frame mounts are made from cast aluminum profiles to guarantee robustness and reliability where needed. The upper subframe is made from injection-molded polyamide, enabling specific flex characteristics and allowing a lightweight construction.
ï New topology-optimized polyamide/aluminum hybrid construction
ï Lower subframe spars and frame mounts made from (cast) aluminum profiles → extremely robust and reliable (no weld joints)
ï Upper subframe made from injection-molded polyamide → specific rigidity and flex benefit handling and comfort
Swingarm
The new hollow die-cast aluminum swingarm is designed to offer optimal stiffness and reliability at the lowest possible weight. The topology has been optimized for optimal rigidity, while an improved casting process reduces weight by approximately 190 g. In order to optimize and match the new chassis flex characteristics, a new 22 mm rear axle is fitted.
Additionally, the chain guard and chain slider have been completely redesigned, resulting in improved durability and less susceptibility to hooking on external objects. This new design will help reduce dirt build up around the swingarm and chain guard, especially in extreme muddy conditions.
Chain adjustment markings are also visible from above to make for simpler adjustment.
ï New die-cast swingarm → topology-optimized for optimal rigidity
ï Improved casting process for reduced weight → 190 g less than previous generation
ï New 22 mm rear axle optimized to match chassis flex characteristics
ï Newly designed chain guard and chain slider
o Transitions aligned with swingarm surface, spring-steel mounted for improved durability
ï Overall, less susceptible to hooking on external objects
WP XACT front fork with AER technology
The 48 mm split air fork features a capsulated air spring and pressurized oil chamber for progressive and consistent damping. Oil and air bypasses reduce pressure peaks and, in combination with a midvalve damping system, the fork provides exceptional feedback and rider comfort. A new hydrostop improves bottoming resistance through more progressive damping force in the last 40 mm of travel. Additionally, rebound is also reduced leading to the fork being lower on initial acceleration after a hard landing. A redesigned fork protection ring increases protection against dirt intrusion.
Settings are easily adjusted via a single air-pressure preload valve, as well as via easy access click adjusters for compression and rebound. Additionally, the air pump needed to adjust the fork's air pressure is provided as standard.
ï WP XACT front fork → 48 mm air type with split damping function
ï Midvalve damping system → exceptional damping and consistent performance
ï Capsulated air spring and pressurized oil chamber → progressive and consistent damping
ï New hydrostop in fork legs → improved bottoming resistance and reduced rebound
o More progressive damping in last 40 mm of travel (total 310 mm) → previous generation hydrostop was only effective in last 10 mm of travel
o Reduced rebound → fork stays lower on initial acceleration after hard landing
ï Easy access clicker dials → simple and fast clicker settings
ï Redesigned fork protection rings → increased protection against dirt intrusion
CNC-machined triple clamps
Made from high-grade aluminum, the CNC-machined Factory Racing triple clamps feature optimally tuned steering stem stiffness, perfect alignment of the fork tubes and precise geometry of the fork clamps to ensure highly responsive and smooth fork action. Maximum gains in handling are provided by simple offset adjustment of 20 mm or 22 mm.
Newly designed, topology-optimized handlebar mounts provide increased grip surface for less handlebar twist at the same weight as the previous generation. Additionally, they allow for both rubber-damped and fixed mounting providing customizable handlebar flex.
ï Rubber-damped → less vibration, less precise front-end feel (OE)
ï Fixed → increased vibration, more precise front-end feel
The front number plate integrates a triple clamp protector which covers the lower triple clamp and protects it from wear caused by roost.
ï CNC-machined aluminum with anodized surface → finest quality and reliability
ï Perfect clamping and alignment → smooth fork action
ï New, topology-optimized handlebar mounts → increased grip surface for less handlebar twist, same weight as previous generation
ï Rubber damping on top clamp → reduced vibration, increased comfort
ï Adjustable handlebar position → adjustable ergonomics
WP XACT rear shock
An all-new design results in a rear shock with 15 mm less overall length and 100 g less weight compared to the previous generation, while keeping the rear wheel travel unchanged at 300 mm. The shock is matched to a revised linkage system with a new geometry to deliver the same progression as before but with the greatest possible traction and absorption. Combined with the new frame geometry, it improves the ground clearance of the linkage and is therefore less susceptible to damage when bottoming out.
The new, computational fluid dynamics (CFD) optimized main piston in the shock improves initial comfort and provides strong hold-up. Differently sized flow holes allow the shims to open more easily and reduce the overall stress of oil flow and pressure on the shims. Reduced weight also means less moving mass, resulting in lower forces on the main piston.
A fully hand-adjustable dual compression control concept allows high- and low-speed settings to be changed by hand. Together with the newly designed rebound adjuster, which is hand or tool adjustable, riders are now able to adjust their shock settings without tools and without the help of a mechanic at the racetrack.
On top of the tool-free setting adjustment possibilities, a new preload adjuster is introduced bringing increased resistance to dirt intrusion. A new two-piece spring retainer allows for quick mounting without splitting the shock.
With its low-friction SKF linkage seals, the WP XACT rear shock provides advanced damping characteristics for unsurpassed traction and energy absorption. A pressure balance inside the shock ensures consistent damping, resulting in superior rider comfort and feel.
ï New lightweight, compact rear shock design with 15 mm reduced overall length
o MY22 → 470 mm / MY23 → 455mm | rear wheel travel unchanged → 300 mm
o Reduced weight results in less moving mass → 100 g lighter design results in lower forces on bearings
ï New CFD-optimized main piston increases initial comfort and guarantees strong hold-up
ï Improved ground clearance, lower risk of damage in extreme bottoming-out situations
ï New dual compression control allows high- and low-speed settings to be adjusted by hand
ï New rebound adjuster allows changing setting by hand or tool
ï Reworked preload adjuster with increased dirt intrusion resistance and quick mounting concept
ï Low-friction SKF linkage seals → refined rear shock response for advanced damping characteristics
ï Pressure balance inside the shock body → consistent damping
ï Two-piece spring retainer allows for quick mounting and assembly of preload adjuster and shock
Brembo hydraulic clutch
The high-performance Brembo hydraulic clutch system guarantees even wear, near maintenance-free operation and perfect modulation in every condition. It means 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 exceptional reliability of the high-quality, Italian-made Brembo hydraulic system.
ï Brembo hydraulic clutch system → perfect modulation and outstanding reliability in every condition
Brakes
The highest level of quality is guaranteed with class-leading Brembo calipers and controls. The 260 mm floating front and 220 mm wave rear discs deliver superior stopping power, instilling confidence in all conditions. A new polyamide composite front disc protector is fitted as standard for added protection.
ï Brembo brake calipers and high-performance discs → superior stopping power with greater control and confidence
ï New polyamide composite front disc protector → added protection and minimal weight
ProTaper handlebar
The ProTaper handlebar is second to none for function and style. Manufactured to exacting standards, the handlebar features class-leading fatigue resistance at a minimal weight. The handlebar bend further increases comfort with an optimal pressure point on the rider’s hands.
ï ProTaper handlebar → class-leading function and style
ï Husqvarna bend → optimal comfort
Grips and throttle assembly
The ODI lock-on grip on the left side does not require gluing, while on the right, the vulcanized grip features an innovative integrated throttle mechanism. The assembly has easy free-play adjustment and, by changing a cam, throttle progression can be altered. The ODI lock-on grips come standard in a softer, grey compound on the Rockstar Editions.
ï Throttle assembly and ODI grips → easily alter throttle progression; easy grip mounting without glue
Footrests
The all-new, CFD designed footrests offer a bigger surface for boot soles while being less susceptible to hooking on deep ruts, take-offs when scrubbing or track barriers. The result is better control of the bike in all conditions. This was achieved by a new, narrower mounting concept integrated in the frame design which also reduces weight.
ï New, topology-optimized, die-cast footrests → reduced weight and less susceptible to dirt build-up
ï Footrest mount integrated in frame → narrower profile is less susceptible to hook on deep ruts
Map select switch, traction and launch control
Designed for easy and intuitive operation, the new map select switch comes as standard on the Rockstar Edition. It activates traction and launch control, selects between two engine maps (aggressive/smooth) and activates the Easy Shift feature. Map 1 is the standard map for linear, predictable power, while Map 2 is an aggressive map for added throttle response and more explosive power output.
The new Easy Shift function (upwards only) 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 opened without the use of the clutch lever. 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 to fifth gears.
With the engine at idle, launch control is engaged by pressing the traction control and Easy Shift switch 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 the rider shifts up a gear, the launch control will deactivate automatically. Additionally, the Easy Shift function is deactivated while launch control mode is engaged.
Traction control is engaged by a switch marked ‘TC’ and functions by analyzing 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 ensuring maximum traction. This is a distinct advantage in wet or muddy conditions.
ï Newly designed handlebar map select switch → alters engine characteristics according to conditions and rider preference
ï New Easy Shift function → clutch-free upshifting
ï Traction control → optimal traction in all conditions
ï Launch control → maximum traction for perfect starts
Start/stop switch
The new combined start/stop switch on right side of handlebar allows for easy, intuitive starting and stopping of the engine.
Engine management system (EMS)
The Keihin EMS is specifically designed to be smaller, lighter and faster at processing data. It integrates launch control for perfect starts, selectable engine maps via the traction control switch on the handlebar as well as the Easy Shift function. Combined with the gear sensor, power delivery is tailored for each gear.
A new rollover sensor (ROS) cuts the ignition in case of extreme crashes, adding another level of safety to the new generation of Husqvarna motocross machines. Additionally, the new hour meter now comes with an integrated FI status LED and a fuel level indicator.
ï Keihin EMS → small, light and faster at processing engine data for more efficient engine management
ï New rollover sensor (ROS) → automatic cutting of ignition in extreme crashes
ï New hour meter with integrated FI status LED and fuel level indicator
ï Gear sensor → specific engine maps for each gear
44 mm throttle body
The Rockstar Edition models feature a 44 mm Keihin throttle body. The injector is positioned to ensure the most efficient flow into the combustion chamber, and to ensure optimal throttle response the throttle cable is mounted directly without a linkage providing more immediate throttle response and feel.
ï Throttle body → 44 mm, injector positioned for optimal flow, more immediate throttle response thanks to direct cable mounting
Exhaust system
The Rockstar Edition exhaust systems are expertly designed to deliver leading performance for the least possible weight. The header pipe features a flow-designed resonance chamber integrated into the header pipe. The header pipe is designed and manufactured in two pieces to be as compact as possible. The position of the join allows it to be removed without having to remove the rear shock. Further innovation allows for a short, compact silencer without increased noise levels. The silencer is crafted from lightweight aluminum and is stylishly finished in a black coating that highlights its premium quality.
ï Compact exhausts → lightweight and engineered for optimal performance
ï Header pipe mounted directly onto engine mount for improved serviceability
ï Header join position → removal of exhaust without removing rear shock
Electric start and Li-Ion battery
To deliver the benefit of an easy electric starting system, a Li-Ion 2.0 Ah battery is fitted to the Rockstar Edition models. The Li-Ion battery weighs approximately 2.2 lb (1 kg) less than a conventional lead/acid battery, so the convenience of electric starting is delivered while minimizing overall weight.
ï Electric starter → easy starting when time is critical
ï Li-Ion battery → lightweight, 1 kg lighter than a conventional battery
Integrated cooling system and radiators
The radiators are expertly crafted by WP using high-strength aluminum. CFD optimization is used to channel air through the radiators more efficiently and provide optimal cooling in any condition. The cooling system is integrated into the frame allowing for improved cooling by channeling coolant through the frame while eliminating the need for additional hoses. A large center tube running through the frame reduces the pressure at this point in the system allowing for a more consistent coolant flow and now includes an internal thermostat for added reliability.
Additionally, the radiators are mounted close to the center of gravity for improved handling agility.
ï Integrated cooling → maximum efficiency in minimum space
ï New bayonet closure radiator caps
ï WP radiators → efficient for optimal cooling
ï Large central tube → consistent coolant flow
Fuel tank
The new 1.9 gallon (7.2 liter) polythene fuel tanks incorporate a threaded filler cap and an integrated fuel pump on the Rockstar Edition models. A new one-piece fuel pump with integrated filter provides improved fuel supply and allows the tank to be emptied further at low fuel levels. The external fuel line is specifically positioned to make it less exposed and susceptible to damage.
ï New 1.9 gallon (7.2 liter) polythene fuel tanks → larger capacity for extended running times
ï New one-piece fuel pump and filter for improved fuel supply → tank can be emptied further at low fuel levels
ï External fuel line routing → less exposed and susceptible to damage
Airbox and tool-less air filter access
The CFD optimized airbox is designed with precisely positioned inlet ducts to prevent air deformation and ensure maximum airflow and filter protection. The air filter is easily accessed, without tools, by removing the left side panel. Easy maintenance is guaranteed by the Twin Air filter element and filter cage design, featuring a simple fail-proof mounting system for safe and accurate filter installation.
ï CFD optimized airbox → improved air flow and maximized filter protection
ï Intuitive filter mounting system → safe and accurate protection against dirt
ï Tool-less filter access → quick and easy maintenance
ï High-flow airbox cover in the by-pack → added customizability of the engine response
Factory wheel set
Black high-strength anodized DirtStar rims by D.I.D are laced to high quality black anodized CNC-machined hubs, using lightweight spokes and black anodized aluminum nipples to offer maximum weight savings and optimized handling and stability in the most extreme motocross conditions.
ï Lightweight but strong and reliable construction → minimal unsprung weight
Tires
Dunlop GEOMAX MX33 Motocross tires featuring the proven ‘block-within-a-block’ design for more progressive cornering and superior grip are fitted as standard.
ï Developed in top-level AMA Supercross and Motocross → enhanced handling, cornering and steering feel
ï Wide range of application including sand, mud, loose surface, and hard pack
ï Increased durability and crack resistance through an innovative rubber compound
Bodywork
The Rockstar Edition models feature bodywork which clearly showcases Husqvarna Motorcycles progressive approach to off-road motorcycles and striking black-and-white graphics stylishly adorn the Swedish-inspired design.
An improved rider triangle for better knee contact, especially when riding in the standing position, inspires confidence for riders of every ability and enables them to perform at the highest level for extended periods of time. The slim contact surfaces on the bodywork allow the rider to more easily move the bike around on track, and improve the overall handling and agility of the bike.
The flat seat profile, combined with the race engineered GUTS high-grip seat cover, deliver superior control in all conditions. A recessed pocket under the seat, just above the airbox, allows gripping and lifting of the bike.
The graphics of the all-new Rockstar Editions closely resemble the look of Husqvarna’s Factory race bikes for the 2022 season. Sponsor logos and graphic design elements are implemented using durable in-mold technology. A high-quality factory race look is guaranteed, even after hours of intense riding.
ï Progressive bodywork → distinctive looks, modern design and graphics
ï Improved rider triangle for better knee contact, especially when riding in the standing position
ï Additional contact surface → allows for improved gripping and easier movement of the bike
ï Recessed grip pockets → allowing better grip to lift the bike
ï Seat → flat seat profile and high-grip Factory seat cover for exceptional comfort and control in all conditions
FC 250 Rockstar Edition
Engine
The newly designed FC 250 Rockstar Edition engine is tilted 2° backwards and therefore comes with a repositioned sprocket which is 3 mm lower compared to the previous generation. The total engine height has been reduced by 8 mm to improve mass centralization and reduce weight (approx. 60 g).
Added service markers on the engine (▲) clearly show where to use washers, making maintenance and service easier than in the past.
All major components and shaft arrangements are carefully designed and placed to best suit the performance and handling characteristics of the overall package, and an added benefit of this new design is improved anti-squat behavior from the whole chassis.
The 250cc engine is not only light at 57.5 lb (26.11 kg) but also remarkably powerful with reworked midrange.
ï New engine design → light and compact for optimized mass centralization
o Engine tilted 2° backwards with repositioned sprocket (3 mm lower)
o Improved anti-squat chassis behavior
ï Engine height reduced by 8 mm for improved mass centralization reduced weight (approx. 60 g)
ï Low-friction design → reduces overall drag and vibration
ï Outstanding high-revving performance engine → enhanced midrange
ï Improved serviceability of engine internals with added service markers
Cylinder head
The fully redesigned DOHC cylinder head features finger followers with a DLC (diamond like carbon) coating resulting in minimal friction and optimal performance. These actuate large titanium valves (32.5 mm intake, 27.5 mm exhaust) which at the 14,000 rpm rev limit open and close multiple times every second introducing fuel/air mixture to the carefully designed combustion chamber to deliver efficient and optimal power throughout the rev-range.
The new 27.5 mm exhaust valve is a result of the new bore/stroke ratio, delivering an optimized gas flow. Valve timings have been adapted to the new valve measurements, working in perfect harmony with the redesigned camshaft.
For improved serviceability and maintenance work within the engine, the redesigned adjustment bush bridge is screwed and increases stiffness. Also, the head gasket comes with a new ‘stopper design’, reducing sealing gap oscillations caused by gas force.
ï Fully redesigned cylinder head → improved durability and serviceability
ï Finger followers with DLC coating → reduce friction and guarantee optimal performance
ï Large titanium valves (32.5 mm intake, 27.5 mm exhaust) with new 27.5 mm exhaust valve → optimized gas flow with revised bore/stroke ratio
ï Redesigned camshaft → adapted valve timing to new valve measurements
ï New adjustment bush bridge increasing stiffness and improving serviceability (screwed design)
ï New cylinder head gasket with stopper design → reducing sealing gap oscillations caused by gas force
Cylinder and piston
The new 81 mm bore cylinder houses a forged bridged-box-type piston made by CP with an extremely light weight of only 150 g. Both the cylinder and piston are professionally engineered from high-strength aluminum resulting in outstanding performance and reliability. The stroke has been adapted to 48.5 mm and the compression ratio has been increased to 14.5:1 for added torque and peak performance.
Thanks to the CFD optimized combustion chamber, the inlet port could be smaller in section resulting in improved engine responsiveness.
ï New 81 mm bore and 48.5 mm stroke (MY22 = 78/52.3 mm)
ï Larger 81 mm bore and larger diameter exhaust valves → high-revving, quick response
ï CFD optimized combustion chamber → smaller inlet port for improved engine responsiveness
ï Compression ratio increased to 14.5:1 → greater torque and peak power
ï Forged bridged-box-type piston → high performance and reliability
Crankshaft
The crankshaft is designed to offer the best possible performance while being perfectly positioned in the engine cases to centralize oscillating masses for optimal handling. The plain big-end bearing features two force-fitted bearing shells ensuring maximum reliability and durability, guaranteeing long service intervals of 100 hours.
ï Plain big-end bearing with force-fitted bearing shells → increased durability and service intervals
ï Friction bearing on the counter-balancer shaft → increased durability
Crankcases
The FC 250 Rockstar Edition engine is designed with mass centralization and weight reduction as main criteria. As a result, the crankcases have been redesigned to house the internal components of the engine in the perfect positions to achieve the ideal center of gravity while adding the least possible weight. Engine mounting points are the same as on the FC 450 engine.
The casings are manufactured using a high-pressure die-cast production process, resulting in thin wall thickness while retaining exceptional reliability.
ï Light and compact crankcases → optimized mass centralization
ï Redesigned engine mounting points (as on FC 450 Rockstar Edition)
ï High-pressure die-cast production process → thin walls for reduced weight while maintaining strength
Gearbox
Produced by Pankl Racing Systems, the new 5-speed gearbox is designed to be extremely light and durable while featuring a 250 cc-specific ratio (24:72). A redesign of the shift shaft reduces the operating forces required for gear changes. A new Easy Shift sensor is positioned on the shift drum, allowing clutchless upshifts. The function can be activated/deactivated via the new QS marked button on the map select switch, located on the left side of the handlebar.
The shift fork has a low-friction coating for smoother shifting, while the new gear lever is designed to prevent dirt build-up and ensure perfect gear selection in all conditions. An advanced gear sensor allows for specific engine maps delivering the best possible performance in each gear.
ï New 5-speed gearbox by Pankl Racing Systems → 250-optimised transmission ratio (24:72) and exceptional durability and improved shifting
ï Redesigned shift shaft → reduced operating force required for gear changes
ï Integrated Easy Shift sensor positioned on the shift drum allows clutchless upshifts → seamless shifting function can be activated/deactivated with map select switch
ï Integrated gear sensor → specific engine maps for each gear
DS clutch
The FC 250 features a DS (Diaphragm Steel) clutch. The exclusive characteristics of this system include a single diaphragm steel pressure plate instead of traditional coil springs.
The clutch basket has been revised and features the same design as on the FC 450, adapted to the new transmission ratio. It is a single-piece CNC-machined steel component that allows the use of thin steel liners and contributes to the compact design of the engine.
ï New clutch basket with same design as FC 450 → adapted for new transmission ratio
ï DS clutch → lightweight with consistent modulation and exceptional durability
FC 450 Rockstar Edition
Engine
The FC 450 Rockstar Edition’s SOHC engine is the perfect example of the advanced engineering techniques used by Husqvarna Motorcycles, offering massive peak power with an overall weight of just 59 lb (26.8 kg), equaling a weight reduction of approximately. 300 g compared to the previous generation.
Mass centralization is key to the engine design, enabling chassis engineers to position the engine closer to the center of gravity for greatly improved handling and maneuverability. This was achieved by tilting the engine 2° backwards which meant positioning the sprocket 3 mm lower. Together with the benefits of mass centralization and reduced weight, the anti-squat behavior of the chassis was significantly improved.
Attention was paid to the serviceability of the new FC 450 Rockstar Edition engine. Drain bosses for fluids and added service markers on the engine (▲) clearly show where to use washers, making maintenance and service easier than before.
ï Engine tilted 2° backwards with repositioned sprocket (3mm lower) → improved mass centralization and improved anti-squat behavior
ï Peak performance and minimal weight → added midrange and improved handling
ï Improved serviceability of engine internals → added service markers and drain bosses for liquids
Cylinder head
The redesigned SOHC cylinder head is incredibly compact and lightweight, with a short profile and the camshaft located as close to the center of gravity as possible. Parallel frame mounts significantly improve handling and agility.
Lightweight valves are actuated via a rocker arm and feature timing specifically designed to deliver precise levels of torque and throttle response. The diameter of the intake valves is 40 mm, while at the exhaust it is 33 mm. A new valve cover reduces the number of mounting screws (only two needed) and a single oil-spray jet guarantees efficient cooling while keeping weight low.
A new fine punched cam chain, low-friction chain guides and the low-friction DLC rocker arm coating offers optimum efficiency, reliability, and durability. Attention was paid to maintenance tasks with lock positions for the cam chain to improve the serviceability of the valve train.
ï Redesigned SOHC cylinder head → more compact design, parallel frame mounts and camshaft closer to center of gravity
ï New lightweight valve cover → only two mounting screws and one oil-spray jet for cooling
ï New fine punched cam chain adding durability
ï DLC coating and low-friction chain guides → optimum efficiency, reliability, and durability
ï Improved serviceability of valve train → lock positions for cam chain
Cylinder and piston
The lightweight aluminum cylinder is an engineering masterpiece, featuring a 95 mm bore. The CP bridged-box-type piston features anodized annular grooves, adding durability and longer service intervals while weighing only 327g. The compression ratio has been increased to 13.1:1 for improved peak performance.
ï Lightweight aluminum cylinder → 95 mm bore / 63.4 mm stroke
ï Lightweight, high-performance CP forged bridged-box-type piston → reduced oscillating masses
ï Increased compression to 13.1:1 → improved peak performance
ï Anodized annular groove → added durability and longer service intervals
Crankshaft
The inertia produced by the crankshaft has been carefully calculated to deliver optimal traction and ride-ability from the powerful 450cc engine. The crankshaft is specifically positioned to harness the rotational mass at the ideal center of gravity resulting in a lightweight, agile-handling feel. A plain big-end bearing comprising of two force-fitted bearing shells ensure maximum reliability and durability, guaranteeing long service intervals of 100 hours.
ï Crankshaft position → ideal center of gravity, improved handling
ï Plain big-end bearing and force-fitted bearing shells → increased durability and service intervals
Crankcases
The crankcases are designed to arrange the shafts and engine internals in the ideal positions to offer the best-possible handling. Additionally, the position of the clutch shaft keeps the clutch above the oil level resulting in decreased drag and increased efficiency. A new steel oil pump gear and repositioned oil jets increase the overall oil pressure, resulting in increased resistance against overheating and improved durability.
High-pressure die-cast production processes keep overall weight to a minimum, resulting in thin wall thickness while retaining reliability.
ï Design → optimized mass centralization and increased efficiency
ï New steel oil pump gear and increased oil pressure → improved durability and resistance against overheating
ï High pressure die-cast production process → thin walls for reduced weight while maintaining strength
Gearbox
The redesigned lightweight 5-speed gearbox is produced by Pankl Racing Systems and ensures the highest level of durability and reliability. A weight-optimized shift shaft reduces the operating force required for gear changes, and the gearbox also features a revised transmission ratio (29:72). The new Easy Shift sensor is positioned on the shift drum, allowing clutchless upshifts. The function can be activated/deactivated via the new QS marked button on the map select switch, located on the left side on the handlebar.
The new gear lever features a design that prevents dirt build-up, and keeps the lever tip in its original position even in the toughest conditions. An advanced gear sensor selects a specific engine map tailored for each gear.
ï New 5-speed gearbox → revised transmission ratio (29:72) for smooth and precise shifting
ï Weight-optimized shift shaft → reduced operating force required for gear changes
ï Integrated Easy Shift sensor positioned on the shift drum allows clutchless upshifts → seamless shifting function can be activated/deactivated with map select switch
ï Integrated gear sensor → specific engine maps for each gear
DDS clutch
The FC 450 Rockstar Edition features a revised DDS (Dampened Diaphragm Steel) clutch. The exclusive characteristics of this system include 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 that allows the use of thin steel liners and contributes to the compact design of the engine.
The main improvements include better clutch cooling from pressure lubrication, reducing clutch fade from high-stress usage while the clutch basket has been redesigned and adapted for the new 5-speed transmission.
ï DDS clutch → lightweight with consistent modulation and exceptional durability
ï Improved clutch cooling from pressure lubrication → reduced clutch fade from high stress
Redesigned clutch basket adapted for new 5-speed transmission ratio