2018 SUZUKI RM-Z450 SUPERMOTO BUILD
P86
Project
Off to AHM
Brandon Petersen from AHM
Factory Services is an extremely
busy young guy who has built
an excellent company with his
buddy Justin Lewis. Located in
Yorba Linda, California, AHM is
responsible for building some
sweet motocross, GNCC, Hare
& Hound and Baja race bikes,
and when I told Brandon we
were finally going to get into the
suspension on the RM-Z, his
eyes lit up.
Brandon made a name for him-
self building flat track bikes and
understands the nuances of sus-
pension across different forms of
racing, so the RM-Z was a bit like
going back to his roots.
The idea was we wanted this
to be a very basic, cost effec-
tive build, one that could easily
be switched back to a standard
motocross setup later in the year
when we gave the bike back to
Suzuki.
"We conducted a standard re-
valve to set up the bike for super-
moto," says Brandon. "The stock
'18 RM-Z suffers big time with a
lot of front and rear pitch, so this
was something we wanted to dial
out as on a supermoto track you
have more time with the fork fully
compressed from high speed
than the quick compression
and rebound you experience in
motocross.
"The rear end in stock trim
wallows under acceleration,
rebounds quickly and puts a lot
of weight back on the front of
the bike which makes the fork
dive. To help with this we uti-
lized a more of a supercross/
arenacross-style of setup. The
spring rate was bumped up in
the forks only as the shock was
sprung proper for rider weight of
192 pounds with no riding gear.
The idea was to have the added
fork spring rate to assist in fork
hold-up under braking and to
keep more pressure on the rear
of the bike, helping it turn.
"The Suzuki's BFRC shock
tends to rebound very quickly
and hurt the front-end feel as it
transfers too much weight to the
front end. As such, compression
damping was stiffened up, as
was rebound damping to slow
the shock down and to help with
rear-end traction, get better drive
and induce less pitching front-
to-back. We also utilized a JGR
lower adjustable pull rod thanks
to John Basher.
"Other than that, no special
parts we needed for this build
The two styles
of supermoto.
Doesn't matter
what you choose,
it just matters
what you're
comfortable with.
