Showa’s SFF-Air TAC forks have lots of potential, but few
riders will ever come to terms with their complex adjustment.
The negative spring, also called the balance spring, is an air
spring that helps the forks resist topping out.
this chamber only holds 7. 5 psi, even if the right-side fork
seals blow, the inner chamber will maintain the integrity
of its air pressure. Thus, the SFF-Air fork can never go
flat as a PSF fork can. The tuning potential of the outer
chamber is minimal, given its minimal air pressure.
Balance chamber. The balance chamber holds 131
psi, but can be set as low as 76 psi or as high as 203
psi. Since the inner chamber and the balance chamber
are diametrically opposed to each other in a pressure
war, the ratio of the two chambers is almost as
important as the amount of air pressure.
Clickers. As with all forks, the SFF-Air has compression and rebound clickers—both found on the left fork
cap. The left leg contains all of the fork’s damping, while
the right leg contains only air pressure, albeit divided
into three chambers. Common sense says that once you
have selected the proper air pressure for your weight
and speed, the clickers would be your go-to tuning
Oil height. As a rule of thumb, raising or lowering
the oil height in either fork tube will change the pressure
rate of the air spring, with lower oil heights producing
a softer fork and higher oil heights delivering a stiffer
feel with more resistance to bottoming. This is still true
on a SFF-Air TAC fork, but there are four different oil-height possibilities. The left leg’s oil height is 340cc. On
the right fork leg, the inner chamber’s oil height is 100cc,
the outer chamber’s oil height is 300cc, and the balance
chamber’s oil height is 10cc.
Q: WHAT IS THE BEST AND WORST THING
ABOUT THE NEW SHOWA SFF-AIR TAC FORKS?
A: The best thing about the SFF-Air fork is that it is
infinitely adjustable. The worst thing about the SFF-Air
fork is that it is infinitely adjustable.
We got lost all the time when trying to fix the forks.
Even with a firm understanding of how all the pieces
of the puzzle went together, they often defied logic. An
obvious change, one that we thought was a natural
progression, would not work the way we wanted it to.
Or, perhaps, it did work the way we wanted it to on that
one chamber, but ruined its relationship with the other
Go to the end of this test to see our settings and read
what we think about the front and rear suspension. We
promise you that they won’t be like anyone else’s.
Q: HOW DOES THE 2015 KX450F HANDLE?
A: It is not a handler. It is a power platform. It is
a base on which Kawasaki mounts its powerful engine.
It is an upright machine that is infinitely stable. It
doesn’t have intuitive handling. It doesn’t do anything
exceptionally well. It just holds the engine so that you
can twist the throttle. Once you understand that and use
it accordingly, you’ll get along fine with it.
Q: WHAT DID WE HATE?
A: The hate list:
(1) Girth. Too big, too tall and too heavy.
( 2) Sound. This bike makes an ear-piercing 120
decibels on the AMA two-meter-max test; however, it
passes the Amateur-required SAE 94-decibel test.