The 2015 RM-Z450 is fun to ride. It’s the ADHD of motocross bikes.
( 2) Shifting. The RM-Z450 has a very light feel at the shift
lever, which in theory is a great trait, but in action, it sometimes
leads to missed shifts and the occasional mystery shift.
( 3) Throttle grip. If you want to install aftermarket grips on
the RM-Z450 throttle tube, lots of luck. It is vulcanized on.
( 4) Brakes. Suzuki’s brakes were nothing special when only
KTM knew what it was doing in the stopping department. But
now that Honda and Kawasaki have joined KTM in the oversize
front-rotor brigade, Suzuki has dropped two more notches.
( 5) Aesthetics. It’s as though Sherman and Mr. Peabody
designed the 2015 RM-Z450 after a trip to 2007 in the Way-Back
Q: WHAT DID WE LIKE?
A: The like list:
(1) Handling. If you want to improve your cornering prowess,
a Suzuki RM-Z450 will do it on the first lap. If you want to get
religion, a Suzuki RM-Z450 will do that on the first whooped-out,
( 2) Powerband. This engine doesn’t set the world on fire.
It’s good but not great. However, what it lacks in raw thrust, it
makes up for with an easy-to-use powerband.
( 3) Tires. Even though they are on the road to being
discontinued, Bridgestone’s 403/404 tires are an MXA favorite.
( 4) Cooling. The RM-Z450 doesn’t steam clean the starting
line while you are waiting for the gate to drop anymore.
Q: WHAT DO WE REALLY THINK?
A: This is a strange machine. It doesn’t have superlative
horsepower, clutch, brakes, stability, looks or ergos. Yet, the
MXA test riders love what the RM-Z450 feels like in motion. Its
one and only great trait is cornering—and for many riders, that is
worth the price of admission. ❏
This is how we set up our 2015 Suzuki
RM-Z450 for racing. We offer it as a guide to
help you get your own bike dialed in.
SHOWA SFF TAC FORK SETTINGS
There is an old saying in motocross
about adjustable suspension—“ 20 clicks of
adjustment…and 19 of them wrong.” This is
how we feel about the Showa TAC forks. They
are too complex with three air pressures, four
oil heights and 20 clicks of both compression
and rebound. It is sensory overload, especially
because each change brings with it a mutation
in all of the other adjustments.
That said, stick close to MXA’s specs. You
will need to fine-tune the pressures for your
speed and weight, but remember that the inner
chamber and balance chamber pressures work
in relationship to each other, and that the outer
chamber, which gets short shrift from both
Suzuki and Kawasaki, can be used as booster
air pressure at the end of the fork’s stroke to
For hardcore racing, we recommend this fork
setup for the 2015 Suzuki RM-Z450 (stock specs
are in parentheses):
Inner spring rate: 170 psi (174 psi)
Outer spring rate: 11 psi (0 psi)
Balance spring rate: 170 psi (174 psi)
Oil height: 340cc (left leg), 100cc (inner
chamber), 300cc (outer chamber), 10cc (balance
Compression: 10 clicks out ( 5 clicks out)
Rebound: 10 clicks out ( 13 clicks out)
Fork leg height: 5mm up
Notes: You cannot recheck the air pressure
with your fork pump (Suzuki does not provide
a pump with the forks, although Kawasaki
does). Because of the high pressures in the
inner and balance chambers, air leaks back
into the pump and ruins the ability to get an
accurate reading. So, never use the pump to
check the air pressure; instead, use the pump
to reset the air pressure to your desired setting. It helps if you write your air pressures
down in a notebook (or on the front fender as
the MXA wrecking crew does).
SHOWA SHOCK SETTINGS
For hardcore racing, these are MXA’s
recommended 2015 Suzuki RM-Z450 shock
settings (stock settings are in parentheses):
Spring rate: 5. 5 kg/mm
Hi-compression: 2-1/4 turns out
( 2 turns out)
Lo-compression: 12 clicks out
Rebound: 10 clicks out
Race sag: 104mm
Notes: In an attempt to find a better fore/
aft balance, the high-speed compression
adjuster can be used to help keep the chassis
flat. We tended to go out a quarter turn.