KTM Announces 2018 SX-F Motocross Bikes | Updates, Specs, and Prices

Coming on the heels of Ryan Dungey’s third consecutive Monster Energy AMA Supercross Championship, KTM has announced its 2018 450 SX-F, along with the 350 SX-F and 250 SX-F—three very similar motocross racing motorcycles. Here are the seven essential facts you need to know, along with full specs.

  1. The 250, 350, and 450 SX-F models share many of the same updates. When KTM improves the breed, it’s not limited to one model—generally all the models get improvement.
  1. KTM is sticking with an air fork for the 2018 SX-F bikes. Continuing to use the controversial lightweight design that replaces a spring with air pressure, the WP AER 48 fork gets a damping setting update. To match the revised fork valving, the WP 5018 shock is also updated. The fork and shock, of course, are fully adjustable.
  1. The five-speed transmission has been improved. The transmission on all three bikes gets a new C4 bearing on the transmission shaft. This means more overlap and KTM claims it improves reliability when things get hot. One 450 SX-F only improvement is a new Metal Inject Molded shift star to handle the 450’s additional power output.
  1. Along with the tranny, the clutch gets update. All three SX-Fs get new nitrated steel clutch plates. This is designed to reduce steel clutch basket wear.
  1. If you ride in the mud, you’ll like the new radiator guards. They’ve been designed to improve airflow on muddy tracks.
  1. The three e-start motocrossers get a new battery. A stronger lithium-ion battery will make sure there’s enough juice to get the bikes started—the 250 SX-F runs a 14.4:1 compression ratio), and they’re ultra-lightweight.
  1. All three race bikes remain less than $10k. The 2018 KTM 450 SX-F hits the floor with a MSRP of $9599, while the 350 SX-F is $9399 and the sticker says $8699 or the 250 SX-F.

2018 KTM 450 SX-F Specs (plus 350 SX-F and 450 SX-F)

MOTOR
Engine: Single-cylinder four-stroke
Bore x stroke: 95 x 63.4mm (350: 88 x 57.5mm; 250: 78 x 52.3mm)
Displacement: 450cc (350: 350cc; 250: 250cc)
Compression ratio: 12.75:1 (350: 14.0:1; 250: 14.4:1)
Valve train: 4-valve DOHC w/ finger followers
Fueling: Keihin EFI w/ 44mm throttle body
Ignition: Keihin EMS
Cooling: Liquid
Lubrication: Pressure w/ two oil pumps
Transmission: 5-speed
Clutch: Wet multi-disc DDS-Clutch w/ Brembo hydraulics
Final drive: 5/8- x 1/4-inch chain
CHASSIS
Frame: Chromoly double-cradle
Subframe: Aluminum
Handlebar: Neken tapered aluminum
Front suspension: Fully adjustable 48mm WP AER air fork; 12.2 inches of travel
Rear suspension: Fully adjustable linkage-assisted WP 5018 BAVP DCC shock; 11.8 inches of travel
Front wheel: 1.6 x 21” Excel
Rear wheel: 2.15 x 19” Excel
Front tire: 80/100-21; Dunlop MX3S
Rear tire: 120/90-19; Dunlop MX3S (350: 110/90-19; 250: 100/90-19)
Front brake: 310mm disc
Rear brake: 260mm disc
DIMENSIONS and CAPACITIES
Wheelbase: 58.5 inches
Rake: 26.1 degrees
Triple clamp offset: 22mm
Seat height: 37.8 inches
Fuel tank capacity: 1.85 gallons
Wet weight (approximate, with no fuel): 222 pounds (350: 220 pounds; 217 pounds)
2018 KTM 450 SX-F, 350 SX-F and 250 SX-F Prices: 450: $9599; 350: $9399; 250: $8699 MSRP

2018 KTM 450 SX-F, 350 SX-F and 250 SX-F Photo Gallery