Inner air chamber: Main reaction force
Balance air chamber: Opposite reaction force
Outer air chamber: Sub-reaction force
Trust us, this is big news, but it’s not the headliner.
Suzuki fit the RM-Z450 with the S-HAC (or Suzuki Holeshot
Assist Control). The S-HAC device is a handlebar-button-
activated device with three modes: smooth, aggressive
and normal. For hard surfaces or slippery conditions at
the starting gate, choose A-Mode. In this setting, Holeshot
Assist Control alters ignition timing to reduce wheel
slip and to deliver a smooth launch to take you into the
lead. Then, after 1.2 seconds (or when you reach third
gear), the system returns to normal ignition timing. If the
traction factor at the starting gate is full loam and a more
aggressive launch is needed, there’s the B-Mode. Here,
it advances the ignition timing to allow increased throttle
response and stronger acceleration off the line. Then it will
return the ignition to normal operation 4. 5 seconds from
start when you shift to fourth gear or when the throttle is
closed, whichever happens first. But, this is just one of the
weapons in the RM-Z’s arsenal.
The new machine has received substantial help in the
starting world. The 2014 model was obstinate and required
a hard kick at a shortish lever. Suzuki’s own factory rider
had trouble starting the Z, and this is what motivated the
changes. They’ve started off stronger by fitting it with a
longer kick lever (30mm), and the redesigned kick gear
increases the rotating efficiency of the crankshaft. In
addition, Suzuki redesigned the decompression system
to make starting easier. This is sweet, but this is not the
whipped cream on the pie.
Oddly enough, the engine appears unchanged. Suzuki
claims that the changes were mainly to the cooling system.
They equalized the water flow between the right and left
radiators and increased cooling flow by 16 percent. The
gearbox got a new shift cam and gear matching for better
action. The power has been altered with an increase down
low via a new exhaust system. This is one area where we
felt big changes. The power wasn’t subtly altered; it hits
stronger, harder, sooner and smoother!
Suzuki reduced the weight of the frame and changed
many of the internal flex points. This proved to be a much
bigger deal than Suzuki’s brief press update let on. The
new Suzuki RM-Z450 has regained its handling appetite
with a softer feel, less transmission back to the rider and
stellar turning prowess.
ON THE TRACK
We’re going to go down the list, just like we’re hopping
on, hitting the track.
Pro Taper bars: good. Clutch pull: easy. Grips: okay.
There is no way to change the bar position via the clamps
as with the Kawasaki KX-F or KTM.
The RM-Z starts about as easily as any four-stroke that
we’ve had to kick. This is huge. Last year it was a nightmare. Now it’s a joy. This one facet elevates the “yes” factor considerably.
Wow, power is immediate; not brutal, not harsh, but
smooth and right out of the hole. The vibration level is way
down. The roll-on is considerably stronger that in 2014
through the bottom and mid, and there seems to be a good
yank on top. We think that this versatile powerplant will
make the Suzuki a good GP bike with its ease of starting,
superb roll-on and strong bottom-to-mid feel with a nice
transition to peak pull.
2015 SUZUKI RM-Z450
Other than the longer header pipe and the
balance air chamber at the bottom of
the new Showa Triple Air, this machine
looks identical to the ’ 14 model. But
once you factor in the new frame,
redesigned engine, new power traits
and the Triple Air fork, you can see
that things are now in an