GP’s Classic Steel #94 89 RM125

For this week’s GP’s Classic Steel, we are going to take a look back at the 1989 Suzuki RM125.

For this week’s GP’s Classic Steel, we are going to take a look back at the 1989 Suzuki RM125.

1989, Suzuki pulled out all the stops with an all-new and completely redesigned eighth-liter racer. Gorgeous to look at and thoroughly modern in design, it signaled a major turn around for the yellow brand.

  

Today, the Suzuki RM-Z250 has become something of the forgotten child of motocross. With no Factory 250 team and no major satellite teams running yellow, they are like the unicorn of professional motocross. They sell in fewer numbers than the other Big Five brands and enjoy less support in the aftermarket. Once the powerhouse of the 125 class, the brand of Rahier, Everts, Barnett and Geboers has fallen on tough times in the new millennium.

In the late seventies and early eighties, Suzuki was the powerhouse of the 125 class.  Bikes like the 1981 RM125-X laid waist to the competition on the track and in the showrooms. By 1985, however, the party was over.

Once upon a time, however, this was not the case. Starting in 1975, with the introduction of the first RM125, Suzuki was a major player in the 125 class. The new Suzuki tiddler featured cutting edge suspension that outclassed the competition and helped launch a dynasty. In America, the RM dominated shootouts and starting lines across the USA. In Europe, the Zook was even more unassailable, capturing every 125 World Motocross title run from 1975 through 1984 (the first ten ever contested). In the late seventies and early eighties, nothing was as sure of a bet as the mighty RM125.

For 1989, Suzuki spec’d out an all-new motor for their 125 racer. The new mill adopted a case-reed layout and a slightly undersquare (54.0 x 54.3mm) configuration to displace 124cc.  Fed by a 35mm Mikuni TMX “Slingshot” carburetor and flowing through and all-new low-boy exhaust, the new motor was easy-to ride, but no rocket.

After this unprecedented run of success, the RM125 fell on hard times in the mid-eighties. Stale designs, engineering missteps and suspect reliability all conspired to knock the perennial champ from its place at the top. Even its once unquestioned suspension domination began to come in question by the middle part of the decade.  With the retirement of the original Full-Floater in 1986, the RM125 became a mere shell of its former glory. Underpowered, poorly suspended and styled like a bike from 1981, the once omnipotent RM was in need of a major change of direction.

O’Show: After two miserable years saddled with sub-par equipment, the new and much improved RM’s were a major breath of fresh air to Team Suzuki’s Johnny O’Mara.

 

Braaappp: Where the old RM mill had been a top-end only screamer, the new case-reed version turned out to be the exact opposite. Snappy down low and very responsive through the middle, it was fun, but not fast. A great novice motor, it lacked the top-end pull to hang with the fastest bikes in the class.

After the disaster of 1986, Suzuki would make some incremental strides toward regaining respectability in ’87 and ’88. The arrival of a new Full Floater and a genuine cartridge fork would alleviate most of its suspension maladies, but its gutless motor and flimsy chassis would remain. For the RM faithful, it would take one more year for long rumored and heavily anticipated all-new RM125 to finally make its appearance.

One unfortunate carryover from the previous RM mill, was the motor’s tendency to grind to a halt at inopportune moments. Crank failures and piston issues were all too common in 1989.

After a decade of stodgy and anachronistic designs, the all-new 1989 RM125 could not have been a bigger departure from its predecessors. Where the old bike featured quirky styling, cobby construction and suspect design, the new machine was the very definition of cutting edge. Bold in design and beautiful to behold, the new RM shed its ugly duckling exterior and adopted a sleek and modern look worthy of the best Hondas of the era. Gone were the goofy duckbilled platypus fenders and poor plastic fitment. In their place, were clean designs that fit perfectly, looked fantastic and rivaled anything from the competition. In addition to the sexy new bodywork, an all-new motor was spec’d and bolted it to a redesigned chassis and suspension package.  After nearly a decade of trailing the competition, Suzuki was ready to come out swinging in 1989.

Buckwheat:  While Bob Hannah was 95% retired from professional motocross by 1989, he did play a major role in the development of all-new RM125 for Suzuki. His influence yielded an excellent handling chassis, but even the Hurricane admitted at the time the little Zook could have used a few more ponies.

While 99% of the RM125 was all-new for ’89, by far the most critical part of the package was its redesigned motor. After the dominant days of the late seventies, Suzuki’s 125 motors went on hiatus in the eighties. Gutless down low and mediocre in the midrange, these Reagan era motors were no match for the powerhouse mills from Honda and Kawasaki. For ’89, Suzuki threw out their moldy old mill and started from scratch in pursuit of a competitive motor.

Lefty: Offsetting the filler cap to the left allowed Suzuki to lower the overall profile of the gas tank for ’89.

With the new mill, Suzuki decided the first thing that would have to go would be the old-school cylinder-reed induction. In its place would be an all-new case-reed design that offered a slightly longer stroke (.5mm), and one additional cc of displacement (up to124cc). By 1989, case-reed induction had become the de rigueur configuration in the 125 class and all the major players were employing this design. In addition to the new cylinder and intake, a new Automatic Exhaust Timing Control (AETC) valve improved exhaust flow and a new 35mm Mikuni “Slingshot” TMX carburetor did a better job of delivering fuel. In the bottom end, a beefier shift shaft (2mm larger in diameter) and bearing-supported shift cam smoothed shifting. Rounding out the package was an all-new pipe and very trick (and quiet) oval alloy silencer.

Mellow Yellow:  While the new RM125 motor was much more responsive than before, it was in no danger of ripping the dyno from the wall. It gave up nearly four horsepower to the Honda and Yamaha and was unable to top even the mild-mannered KX125 in the power rankings.

On the track, the new 124cc mill was the polar opposite of the ’88 RM power plant. Where the old mill was a top-end-only rev ranger, the new case-reed edition was perky off idle and extremely responsive to throttle input. Any twist of the right grip was met with immediate forward motion and a quick climb up onto the powerband. Torque off idle was excellent (for a 125) and the midrange was solid, if not awe-inspiring. After the snappy midrange hit, the party was over, and the RM demanded another shift to keep the fun going. This made the new RM a real favorite of novices, but a disappointment to fast intermediates and pros. Its incredibly responsive power was fun, but not particularly fast.

Full Works:  In 1987, both Donny Schmit and Erik Kehoe (and Bob Hannah at the MXdN) raced pre-production versions of ’89 case-reed RM125 mill at the 125 USGP. While the works version was reportedly a rocket ship (powering Kehoe to the ’87 USGP victory) the production version seemed to lose something in the translation.

In the powerband sweepstakes, the new RM was at the back of the horsepower pack in 1989. It gave up nearly four horsepower to the CR125R and YZ125 and lagged behind even the mellow KX125. It was the snappiest bike out of the hole and very quick from turn-to-turn, but no match for the others once the track opened up. For novices it was a great motor, but if you were an aspiring Mike Kiedrowski, there were better choices.

Too Rad:  While I’m pretty sure the signs were a bit of an overstatement, there can be no denying the fact that the new RM’s were very trick.

 

In 1989, Johnny O’Mara caused quite a stir by deciding to step back down to the 125 class at the conclusion of the 250 Nationals (Suzuki did not have a Open bike for him to ride in the 500 Nationals at the time). While many accused the O’Show of cherry picking, those fears proved unfounded. Mounted on an obviously underpowered machine, and facing fierce competition (including Mike LaRocco, Damon Bradshaw and Mike Kiedrowski, just to name a few),a third at Spring Creek would be the best the former champ could muster against the kids.

In the chassis department, Suzuki again went back to the drawing board for 1989. The all-new frame was both stronger and lighter than the ’88 version, offering a fully boxed swingarm pivot for the first time. There was also slightly more rake and trail than ’88 (28 degrees and 4.6 inches vs. 27/4.3 on the ’88) and an additional head stay to increase strength and decrease vibration. In the rear, the left rear subframe tube was now aluminum (to save weight) and easily removable (to aid shock servicing).

In Europe, Suzuki had a strong Factory presence in 1989. Alex Puzar would campaign the new RM under the while Chesterfield colors, but lose out in the eventual title fight to a virtually unknown American from Louisiana, by the name of Trampas Parker.

Handling was further aided by an all-new layout that was slimmer (an inch narrower at the side-panels), flatter and carried its weight lower on the chassis. The new radiators were mounted 2 lower on the frame and the gas tank carried its fuel a whopping 5.1 inches lower than ’88. The top of the tank was also 1.4 inches lower, resulting in a less sloping seat for easier rider movement.

The excellent reputation Suzuki enjoys for handling prowess started in earnest with the 1989 RM125 and RM250. The new bikes did away with the cranky manners of past RM’s and replaced them with a razor sharp personality that shredded turns and leapt tall buildings in a single bound. Bob Hannah demonstrates.

 

In Europe, Dave Strijbos chose to run inverted forks on his 1989 works Suzuki RA125. The USD’s would see production on the 1990 RM125.

On the track, the handling of the new RM was a huge step forward from its mediocre predecessors. Cornering was razor sharp and the new ergos made moving a breeze. In the turns, only the CR was close to the carving manners of the Suzuki tiddler. Unfortunately, the flip side to this agility was a busy feel at speed. In choppy high-speed sections, the RM could exhibit enough headshake to remove your hands from the bars and your Powerbar from your bowels. For most riders, this was a fair trade off and a welcome improvement over the clanker it replaced.

For 1989, Suzuki decided to stick with their tried-and-true conventional cartridge forks over the more en vogue inverted designs. By upping the size of the stanchions to 46mm, they added rigidity, without sacrificing the feel riders appreciated. Exceedingly plush and well damped, they were some of the best forks of 1989.

In the suspension category, rigidity was the buzzword of 1989. It was at this point in motocross history than many of the Japanese manufacturers started to make the transition from conventional forks to the new wave of inverted designs. The advantage of these new USD forks was a significant increase in rigidity, at the cost of a plush feel. While riders like Ricky Johnson and Damon Bradshaw could appreciate this added stoutness, more mortal riders found them a significant step backward in performance.

Zip-Ty: While Suzuki fielded a strong team of talented young riders on the new RM125 in 1989; they were badly outgunned in the 125 Nationals. Team riders, Ty Davis (pictured), Erik Kehoe, Jimmy Gaddis, Johnny O’Mara and Buddy Antunez all struggled to keep the ultra-fast Hondas in sight all summer.

For ’89, Suzuki tried to address this desire for added rigidity by increasing the diameter of their excellent Kayaba conventional forks.  The new units retained the conventional layout of the year before (the RM250 adopted the USD’s for ‘89), but upped the diameter of the stanchions 3mm to a total or 46mm. This put them on par with the similar 46mm units employed on the ‘89 KX125 and allowed them to pull ahead of the old-school 43’s mounted to the front of the CR125R (Yamaha went with a 41mm inverted KYB fork for the YZ125). The RM’s KYB’s featured a cartridge design and 21 adjustable settings for both compression and rebound.

While the new bike was a major improvement in most areas of quality and detailing, the RM remained the most time consuming of the Big Four 125’s to strip down.

In terms of actual performance, the new RM’s forks were some of the best units available in 1989. Big hits were taken in stride and the action was very plush on all surfaces. A wide range of adjustment was available and most riders could find a satisfactory setting with the stock springs and valving. Action was not quite as flawless on small hits as the Kawasaki, but performance was far superior to the Honda and Yamaha.

Jimmy Gaddis would sail the new RM125 to a sixth place overall finish in the 1989 125 West Coast Supercross series.

In the rear, Suzuki spec’d an all-new shock and Full Floater linkage for ‘89. The linkage retained the same ratio as 1988, but was lighter due to a switch to lightweight aluminum from the previous steel.  The new shock was also lighter and delivered 21 adjustable compression settings and 18 selectable rebound adjustments to go with its 12.8 inches of travel. Performance out of the box was excellent and the new-school Full Floater made quick work of most track obstacles. On small hits, it was particularly plush and one of the smoothest rides of ’89. Its only flaw was a propensity to bottom out a little too soon on really hard hits. Overall, it was the second best rear end of ’89 behind the extremely well sorted KX125.

Other than an unfortunate misstep in 1986, Suzuki RM’s reigned as the King of rear suspension for well over a decade in the 125 class. The Full Floater rears were renowned for their plush performance and excellent feel. For ’89, Suzuki continued that tradition with an all-new rear end that gobbled whoops and made braking bumps disappear. Only the super-plush KX125 offered a better ride in 1989.

In terms of detailing, the new RM was a quantum leap forward from previous Suzuki’s. The plastic fit and finish were far better than in the past and the bike no longer looked like it was slapped together by three different committees that never spoke to each other. Brake feel and power were improved with thicker rotors front and rear, new pads and a larger diameter disc for the front. New grips (Honda clones), levers and bars (still butter-soft steel) aided hand comfort and a firmer seat aided butt comfort. Fastener selection (far too many different sizes) and quality (pot metal) continued to lag behind the standards set by Honda, but at least the Phillips screws were gone (Halleluiah!).

Even a mega-sweet mullet were not enough to make up for the mellow motor and power Budman to the front in 1989.

While the overall motor design was thoroughly modern and well thought out, the glaring omission of a removable clutch cover was disappointing in an all-new design. At least clutch life was decent. Reliability continued to be a Suzuki bugaboo, as the little RM proved to be the least dependable of the big-four tiddlers. Piston and ring life was poor and manufacturing issues led to a rash of rod failures that did the RM’s already dubious reputation for quality no favors. At least the little Zook looked great.

In 1989, Suzuki finally stepped up to the plate with an all-new RM125. The bike was sleek and slim, easy on the eyes and fun to ride. If only it had offered a motor with some juice, it would have been the best 125 of ’89, but alas, twas not to be. Still, it was a solid bike with lots of potential and the foundation for a machine that would capture the 1990 AMA 125 Motocross and 125 World Motocross championship.

In 1989, Suzuki made a major step back toward respectability in the 125 class. After nearly a decade of duds, the new RM125 was a breath of fresh air for the Suzuki faithful. This bike continued Suzuki’s reputation excellent suspension, while launching a new tradition of handling excellence. It was no rocket ship, but it was snappy, fun and competitive below the pro class. It was a solid foundation that would lead to some of the best 125’s of the 1990’s.   

For your daily dose of classic motocross goodness, make sure you follow me on Instagram and Twitter – @TonyBlazier