KTM Announces 2018 SX-F Motocross Bikes | Updates, Specs, and PricesComing 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.
- 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.
- 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.
- 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.
- 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.
- If you ride in the mud, you’ll like the new radiator guards. They’ve been designed to improve airflow on muddy tracks.
- 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.
- 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.
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
Lubrication: Pressure w/ two oil pumps
Clutch: Wet multi-disc DDS-Clutch w/ Brembo hydraulics
Final drive: 5/8- x 1/4-inch chain
Frame: Chromoly double-cradle
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