The RM-Z450 has always been an unfinished
project. It oozes desirability thanks to its incredibly accurate cornering and a powerband that
makes the most of what it has. Then, it shoots
itself in the foot with a Tinker Toy clutch,
inadequate cooling system, spongy brakes and less than
class-leading suspension. So, for 2015, Suzuki gave it
the old college try with all-new SFF TAC air forks,
reconfigured radiator hoses and a bundle of electronic
gizmos. Sadly, the clutch and brakes remain archaic.
Cornering. One of the common misconceptions is
that the Suzuki RM-Z450 is the best-handling bike on the
track. That’s not true. It is the best-cornering bike, not
the best handling. When it isn’t turning left or right, it is
nothing to write home about; but, when it comes to
making sharp cuts, it has no equal.
Powerband. Every MXA test rider likes the Suzuki
RM-Z450 engine. Yes, there are faster engines on the
showroom floors, but they don’t offer the flexibility of the
low-to-mid Suzuki powerplant. Good thrust without much
Electronics. The 2015 RM-Z450 not only has three
plug-in maps, but it has three “launch control” options—
stock, mellow and aggressive. Yes, that is one more than
what Kawasaki offers, but not necessarily one-third
Forks. The new Showa SFF TAC air forks are better
than last year’s Showa SFF single-spring forks, but that
is a target that a set of 30mm Hodaka forks could have
hit. Last year’s forks were horrible. This year’s forks are
all the rage, but most of that rage is aimed at how hard
they are to adjust.
Clutch. What clutch? If you use it, you will lose it.
Brakes. With Honda and Kawasaki joining KTM in
the oversized brake parade, Suzuki and Yamaha are
High-speed handling. You gotta give to get. Suzuki
gave up stability in search of Supercross cornering ability. On smooth tracks with lots of jumps and no high-speed sections, you’ll be happy.
Looks. Don’t park your 2015 RM-Z450 next to a bunch
of 2008 through 2014 RM-Zs, because you won’t be able
to pick yours out of the crowd.
BEST SUSPENSION SETTINGS?
Forks. These are MXA’s recommended 2015 Suzuki
RM-Z450 fork settings (stock settings 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 chamber)
Compression: 10 clicks out ( 5 clicks out)
Rebound: 10 clicks out ( 5 clicks out)
Fork-leg height: Flush with the top clamp
Notes: The inner-spring air pressure is your base spring.
Set it where you think it should be based on your weight
and speed, then set the balance air pressure to make the
forks stiffer or softer (more air in the balance chamber
makes the forks softer). Finally, we added air pressure to
the outer chamber to lessen bottoming. We aren’t telling
tales out of school when we say that these forks, with their
complicated air pressure interrelationship, are the most
complicated forks ever made.
Shock. These are MXA’s recommended 2015 Suzuki
RM-Z450 shock settings (stock settings are in parentheses).
Spring rate: 5. 5 Nm
Race sag: 104mm
Hi-compression: 2-1/4 turns out ( 2 turns out)
Lo-compression: 12 clicks out
Rebound: 10 clicks out
Notes: Use the high-speed compression adjuster to help
balance the chassis at speed. Turn it in to raise the rear
and turn it out to lower it.
WHAT DID WE CHANGE?
Here is the short list of things the MXA wrecking crew
changed on the 2015 Suzuki RM-Z450.
(1) We added stiffer Pro Circuit clutch springs on day
one. And, we keep Hinson’s number on speed dial.
( 2) We install the white plug-in coupler to get the best
( 3) We never use the aggressive “launch control” map,
preferring to use the stock map on dirt and the mellow
map on concrete.
( 4) We always make sure that there is free play in the
rear brake clevis. This prevents the brakes from
WHAT DO WE THINK?
This is a strange machine. It’s both good and bad. 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 great trait is
cornering—and that’s worth the price of admission. ❏
MXA RODE TEST