Kayaba's new generation PSF forks use a pressured air chamber in each fork to replace the need for the traditional main springs. The chambers reduce front-end weight by up to 750g and friction by 20%. Adjusting the "spring rate" inside the PSF forks is as easy as attaching a readily available bike pump with a special adapter available from Kawasaki to increase or decrease the chamber's air pressure. Kawasaki claim that the PSF technology allows a wider and easier range of adjustability and settings, increased bottom resistance with bigger pistons providing more surface area, and even better on-track performance and handling.
On paper, Kayaba's Pneumatic Spring Forks appear to be in direct competition with Showa's SFF AIR fork that has been under heavy testing over the past two years with James "Bones" Bacon and Pro Circuit Kawasaki on Broc Tickle's KX450F in the United States. Read our interview with Bones Bacon:
However the all-new Kayaba PSF suspension isn't the only update to grace the 2013 KX450F. Following on from the new, quicker turning, chassis released with the 2012 model, there are also updates to the 2013's bodywork, including a new front fender and decals. The engine has been updated with a new piston and cam profiles, and there's revised ECU settings to boot. The KX-F will still come with launch control and easy engine tuning through the supplied DFI couplers. A new muffler has been bolted on to comply with stricter noise emission standards. You'll also notice a revised set of front and rear brakes, silver finished engine covers (instead of black) to accompany the adjustable handlebars and footpegs from last year.
While the 2013 KX250F will be officially launched on Australian soil at Appin, NSW, June 12, Kawasaki Australia's, Rudi Baker, expects to see the KX450F land in mid-July.
If you're interested in Kawasaki's marketing spin and specs list on the 2013 KX450F you can download the PDF here.