Words: MITCH BOEHM PHoTos: DavE DaMEs, sCOTT

Words: MITCH BOEHM
PHoTos: DavE DaMEs, sCOTT anDErsEn
WWW.MOTORETROILLUSTRATED.COM
04MR_RM125.indd 71
71
1/30/11 6:53:15 PM
Suzuki RM125
for an hour just looking at the things. So when
Suzuki introduced the RM125 with that media
blitz and that classic “Holy $*&%#!!” 2-page ad,
I was hooked and just had to have one. To me
it was like having a factory bike in the garage.
It handled sooo much better than my TM even
though it wasn’t quite as fast as the Elsinores.”
Suzuki led what could only be called a double
life in the world of motocross from ’70 to ’75. On
the Grand Prix side of the ledger it could do no
wrong, winning multiple world championships
with Joel Robert and Roger DeCoster during the
first half of the decade on some of the trickest
and lightest factory machines the world had ever
seen. Robert’s 1972 RH72 racer, for instance,
weighed only 168 pounds thanks to judicious
use of titanium, magnesium and truly innovative
design.
Things were wildly different on the production
side, however, the company’s TM400 Cyclone,
TM250 Champion and TM125 Challenger
attempting to give the buying public some
semblance of the functionality of the ultralight
works bikes of Robert and DeCoster — but
failing miserably.
“Suzuki’s had the technology to build a
killer motocrosser for five years,” wrote Cycle
in its September, 1975 Edition. “Yet [they’ve]
never…made an effort to apply their Grand Prix
technology to production machines. The TM125
was only competitive for a year. The TM250 has
been a neat playbike, and never a motocrosser,
for four years. The TM400, long known for its
brutal power and uncontrollable chassis, made
you feel like wrestling alligators for relaxation.
Consequently, Suzuki’s reputation was that of
a company that played on the names of Robert
and DeCoster to sell production bikes that didn’t
share so much as a sump plug with the real
racers.”
Tough words, but true ones nonetheless.
Everything turned in early 1975, however,
when Suzuki’s efforts to totally reshape its
production motocross line became public via the
first-generation RM125M, introduced at Suzuki’s
annual dealer meeting. “About a year ago,”
wrote Cycle’s editors, “a management change
in Japan resulted in a decision which brought
us the RM125. This bike, so we are told, is only
the beginning of a new thrust by Suzuki to get
serious with their motocrossers. We expect
to see an RM250 and RM400, hopefully with
enduro counterparts…”
Suzuki didn’t know it at the time, but this
upper-management change — and the productoriented directional swerve it produced —
would figure heavily in Suzuki’s speedy rise to
power in mainstream motocross, the RM125M
forming the very tip of the spear the company
used to do the deed.
The RM125M wasn’t an all-new motorcycle,
but it did offer bold technical advances over its
TM-spec bretheren, and set the stage for a line
of all-new RM-spec motocrossers that would
appear in 1976 and beyond.
“The RM125M,” says RM expert Scott
Andersen, “was Suzuki’s first real attempt
to build a truly competitive 125 for mass
production. To do this it dug deep into its parts
bin. The engine is basically a hopped-up TM125
mill with a heavier-breathing cylinder and
transfers, a new pipe and a larger carburetor.
The frame is also TM-spec, the back half
modified to support the laid-down shocks and
7.4 inches of travel — a lot for that era. Long
travel was the leading edge in 1975; kits were
available to modify the suspension of existing
bikes, and they sold like crazy. But Suzuki
had done it for you. The fork came from the
TM250/400, and was an improvement over the
72 MOTO RETRO ILLUSTRATED
04MR_RM125.indd 72
1/30/11 6:53:41 PM
Above: Despite its TM-spec tank, frame and
engine base, the RM125’s massive laid-down
Kayabas, bulging side panels and humped seat
gave it factory-esque looks. Left: The magazines of the day (from left, Cycle, Dirt Bike and
Cycle Guide) gave the RM high marks despite
its slight power handicap. Handling made the
difference, and with Suzuki’s hop-up kit (or the
aftermarket’s), it was right there.
TM125’s flimsy tubes, with stiffer stanchions
and more travel. Amazingly,” adds Andersen,
“the RM’s gas tank, fenders, handlebar, pegs
and controls all came from the TM125. The
only new parts made for the RM were the
triple clamps (to match the bigger fork tubes),
shocks, airbox, side panels, seat and exhaust.”
It all worked, at least reasonably so.
According to both Cycle and Cycle World (both
used the legendary Webco dyno), RM125M
testbikes made 18.5 and 19.6 bhp, respectively,
at the countershaft sprocket, a bit less at the
rear wheel. The Yamaha YZ125C and CR125M
posted numbers a horsepower above the RM’s
output. The power king of the 125 class was
the then-new Can-Am MX125, which busted out
22.5 ponies on the same dyno. Three to four
horsepower doesn’t sound like much, but on
bikes with this sort of power-to-weight ratio,
it was a lot — some 20 percent. Aftermarket
goodies such as pipes, carbs and heads helped
level the field, especially when combined with
trick ignitions and quality porting work. Plenty
of companies jumped on the RM bandwagon,
DG, FMF and Miller Mano being three of the
most aggressive.
Suzuki offered a hop-up kit of its own,
consisting of a ported cylinder, modified piston
and intake manifold, 34mm Mikuni carburetor,
WWW.MOTORETROILLUSTRATED.COM
04MR_RM125.indd 73
73
1/30/11 6:54:10 PM
Suzuki RM125
larger air boot and air box, and hand-rolled cone
pipe with different dimensions and a longer
stinger – all for $200. It boosted peak power by
about 2 ponies, matching or slightly bettering
the output of the YZ125C and Elsinore, while
maintaining the stocker’s midrange hit but
reducing low-end a touch.
The added power made the RM plenty
competitive, especially when you factor in its
long-travel suspension and capable handling
manners. “Going fast brings out the efficiency of
long-travel suspension,” Cycle wrote. “A casual
pace overplays the severity of a given bump…
the bike pitches and yaws and doesn’t steer
properly. Hit the same terrain at speed and your
hands and feet get thudded sharply while the
bike continues in a straight line. This increases
your speed on rough straights more than
anywhere else.”
While Cycle complained that the bike’s
longer travel and the more obvious chassis
pitching that came with it made hard braking
and initiating slides more difficult, it clearly
identified the Bottom Line: “Since laps times
improve by as much as 10 percent almost
immediately, the advantages of long travel
outweigh the peculiarities. Riders will adapt
their styles accordingly and then the old bikes
will feel ‘different’. In the end, long travel means
more control over bumps — which means more
speed.”
Suddenly, Suzuki had gone from also-ran to
contender. The stock bike was cheap ($775 on
the west coast and $925 at retail) and plenty
competitive for novice and intermediate racers.
And with the aftermarket’s (or Suzuki’s) added
engine poop, experts and pros could win on
it as well. Cycle World wrote in its September,
’75 issue that it wished the bike would have
come with the added power (and a 6-speed
transmission to better harness it) as standard
equipment, even at a higher price. But in
the end, they — like the Cycle editors — had
to admit the RM125 was a highly capable
motocrosser, and a far better bike than the
TM125 (a descendant of the TS125 Duster of
1971) it sprang from.
Top: Suzuki’s alternate print ad wasn’t as
catchy as the “Holy @*&%!!” version, but
it conveyed the same message — that the
RM would rev to the moon and outhandle
any other 125 on earth. Right: Factory-kitted
RM125 (owned by Dave Dames) features a trick
pipe, carb, cylinder, piston, etc. and added
about 2 ponies — enough to keep up with the
Elsinore and YZ125C.
74 MOTO RETRO ILLUSTRATED
04MR_RM125.indd 74
1/30/11 6:54:44 PM