Kawasaki has made another major leap in the evolution of 450cc motocross bikes with the new 2015 KX450F. While Kawasakiâ??s flagship MX platform has, by far, been the most successful bike on the AMA circuit over the last several years in the very capable hands of Ryan Villopoto, factory equipment can be vastly different from stock machinery. However, the gap between works and working class machinery shrinks with each passing year it seems. For 2015, that gap shrank a little bit more with the introduction of the all-new Showa SFF-Air TAC Fork with Triple Air Chamber.

When throwing a leg over the KX450F you immediately notice the comfortable ergonomics and spacious cockpit. The KX is made even more spacious thanks to four-way adjustable handlebar mounts and adjustable footpegs, which can be lowered 5mm. Complimenting all of this are a frame and seat that both allow the rider ample grip on the machine and plenty of space to move around while attacking the track, which is what the Kawasaki does best.

The motor starts with a strong low-end that is perfect in deep, sharp, rutted corners and seat-bounce jumps. The power then builds into a beefy mid-range hit that is improved for 2015 with the new Bridge Box piston. For the majority of riders, the mid-range RPMs are the most essential and that is exactly where the Kawasaki shines. From second to fourth gear, there is enough grunt to take on just about any obstacle on a medium-sized track. At a facility such as Milestone MX, a rider can be plenty aggressive while riding in third gear 90% of the time.

Specification:

Engine: Liquid-cooled, four-stroke single with DOHC and four-valve cylinder head
Displacement: 449cc
Bore x stroke: 96.0 x 62.1mm
Fuel Injection: DFI with 43mm Keihin throttle body
Compression ratio: 12.8:1
Ignition: Digital DC-CDI
Transmission: Five-speed
Rake & Trail: 27.9 degrees / 4.7 inch
Front suspension: Inverted Showa SFF-Air TAC fork with Triple Air Chamber, DLC coated sliders, 22-position compression and 20-position rebound damping adjustment, with 12.4 inches of travel.
Rear suspension: UNI-TRAK linkage system and Showa shock, 19-position low-speed and 4 turns high-speed compression damping, 22-position rebound damping and fully adjustable spring preload, with 12.4 inches of travel.
Front tire: 80/100-21
Rear tire: 120/80-19
Front brake: Single rigid-mount 270mm Braking petal disc with dual-piston caliper
Rear brake: Single 240mm Braking petal disc with single-piston caliper
Overall length: 86.4 inch
Overall width: 32.3 inch
Overall height: 50.2 inch
Wheelbase: 58.8 inch
Ground clearance: 13.4 inch
Seat height: 37.8 inch
Curb weight: 247.1 pounds
Fuel capacity: 1.64 gallons