KTM makes a lot of changes to its World and National Championship-winning four-stroke MX models.
KTM has made numerous changes to its championship-winning line-up of four-stroke models. Following the company’s recent theme, many of these improvements are based on the previous year’s Factory Edition models.
2016 KTM 450 SX-F
KTM says that the 2016 KTM 450 SX-F’s engine is lighter and more compact than ever before. Its engine cases have been redesigned to better centralize the rotating mass of the crankshaft and clutch. This new positioning also reduces overall length and width of the cases. Claimed weight for the new machine is 224.7 lbs.
The 450’s fuel-injection system features a completely reworked Keihin Engine Management System with a new 44mm throttle body, and it includes a new electronic Launch Control designed to net the 450 better starts. The new system also offers multiple engine maps to allow the rider to tailor the overall power delivery to suit track conditions.
Mechanically speaking, new cylinder head combustion chamber geometry, optimized ports, a shorter timing chain and friction reducing chain guides have been incorporated to improve power and reduce weight. The cylinder itself is 6mm shorter, and it houses a lightweight piston connected to a shorter connecting rod and a crankshaft with 10% more inertia.
A new, lighter 5-Speed transmission is also part of the package. The trans is narrower than before, and it and features a new surface treatment on first and fifth gears along with a special low-friction coating on the shift forks to improve shifting ease and precision. A new “No Dirt” shift lever is also used to prevent dirt from fouling the lever joint and thus help to ensure proper shifting in any conditions. Power is transmitted through one of KTM’s DDS (Damped Diaphragm Steel) clutches, this one using a new, lighter basket along with a reworked inner hub and pressure plate designed to provide better oil supply and improved cooling of the clutch.
The 450 SX-F’s electric starting feature has also been improved via a new, super compact and lightweight 1.1-lb. Lithium-Ion starter battery. A new WP flow-optimized radiator design is used to improve engine cooling, and a new Flow Design Header (FDH) with an integrated sound resonator is claimed to increase power. The system’s lightweight silencer is 40mm shorter than the previous design, and KTM says that it helps with the 450’s quick throttle response.
The 450F’s chassis is also changed. The chromoly steel unit is lighter and provides higher torsional rigidity with less longitudinal stiffness which, KTM says, results in improved handling and energy absorption. The accompanying new subframe design is made with new aluminum profiles, and it is lighter than the previous version. The 450’s swingarm is also lighter and features a revised internal structure to match the new frame characteristics.
Naturally, the 450 uses a WP 4CS (Four Chamber System) Fork that has been specifically designed for motocross. It features revised damping settings that have been optimized for the new chassis. Ditto for the new-generation WP shock that has been developed in conjunction with the new frame and swingarm architecture and included a new linkage/pullrod system
Like the shifter, the 450’s footpegs utilize KTM’s “No Dirt” design to provides a larger surface area, and they also feature a “scraper” to reduce dirt build-up in the hinge area. New CNC- machined upper triple clamp feature a rubber damping system for the new Neken handlebar and ODI lock-on grips. Other noteworthy items include super-lightweight Galfer Wave rotors, CNC-machined hubs, high-end Excel rims and Dunlop GEOMAX MX32 tires as standard equipment.
2016 KTM 450 SX-F Specs
Engine Type: Single cylinder, 4-stroke
Compression Ratio: 12.7.5:1
Starter/Battery: Electric Starter / 12V, 3Ah
Transmission: 5 gears
Fuel System: Keihin EFI, 44mm Throttle Body
Lubrication: Pressure lubrication with 2 oil pumps
Primary Ratio: 31:76
Final Drive: 13:48
Clutch: Wet multi-disc DDS-clutch, Brembo hydraulics
Ignition: Keihin EMS
Frame: Central double-cradle type 25CrMo4 steel
Handlebar: Neken, aluminum Ø 28/22mm
Front Suspension: WP USD 4860 MXMA 4CS
Rear Suspension: WP monoshock 5018 BAVP DCC w/linkage
Suspension Travel Front/Rear: 300mm/11.81 in.; 300mm/11.81 in.
Front/Rear Brakes: Disc 260mm/10.24 in.; 220mm/8.66 in.
Front/Rear Rims: 1.60x 21, 2.15 x 19 Excel
Front/Rear Tires: 80/100-21 in.; 120/90-19 in. Dunlop MX32
Chain: 5/8 x 1/4 in.
Steering Head Angle: 26.1º
Triple Clamp Offset: 22mm
Wheelbase: 1,485mm ± 10mm / 58.5 ± 0.4 in.
Ground Clearance: 370mm / 14.6 in.
Seat Height: 960 mm / 37.8 in.
Tank Capacity, Approx: 7.2L / 1.9 gal.
Weight (without fuel), Approx: 101.9 kg/ 224.7 lbs.