TransWorld Motocross Race Test: 2004 Suzuki RM-Z250 – Separated at Birth

Last month, we offered our first impression of the all-new 2004 Kawasaki KX250F. Though we have yet to take a second spin on the green machine that we were allowed to thrash for a day at the mass introduction, we have spent a considerable amount of time aboard the green machine's twin brother of a different color: the 2004 Suzuki RM-Z250.

At first, we thought we'd be funny and reprint the same exact bike test that we ran in the last issue. Seeing as how the Kawasaki and Suzuki are the exact same bike, save for different plastic body parts, who could blame us? After spending two solid months with the little yellow thumper, however, we've gained a much better impression of the bike and how it works in various conditions.

Each and every time we've been to one of our local tracks with the RM-Z, the second most common question we hear is, “Is it faster than the Yamaha?” (The first most common being, “Can I take it for a spin?”) The answer to both questions? No. Don't get us wrong, however, as the RM-Z (and KXF) are definitely not slow. Perhaps it isn't even correct to say that the RM-Z is not as fast as the Yamaha, as different riders have different opinions of what “fast” is. What are the main differences? While the Yamaha has a big mid-range hit and a super top-end pull, the RM-Z has snappier low-end throttle response and excellent mid-range. On top, though the motor seems to rev way out, the power just doesn't feel as strong as the YZ engine's. Where the Yamaha has a little extra “oomph” up in the upper echelons of the rpm range, the RM-Z simply revs out in a linear, unexcitable manner. On tight tracks with lots of cut-and-thrust corners and straightaways, we found the RM-Z to be a much easier bike to go fast on, thanks to its snappy low-end. At the same time, however, faster hard-packed courses with little traction were not as compatible with the bike, as its lack of engine braking seems to eliminate the “four-stroke traction advantage” all together. Furthermore, the engine's tendency to flatten out on top when revved out in each gear forces riders to shift sooner. Though none of the aftermarket companies had finalized their production exhaust pipes at press time, we did have the good fortune to try a couple prototype systems and can report that plenty of power can be gained up top with the addition of a new muffler.

One thing that we have noticed about the RM-Z in the past few weeks is that in the hands of an aggressive rider, the bike tends to run a little on the hot side. In addition to paying close attention to the radiator fluid levels, we've found that replacing the stock radiator coolant with Engine Ice helps the little thumper run cooler. Regular oil changes are also a good idea, especially when the bike has been run hard and hot. And speaking of “hot,” we are pleased to report that the bike does, indeed, fire right back up when the engine is hot. Even after a tip-over crash, a couple stabs at the kickstarter with the hot-start lever engaged is all it takes to bring the RM-Z back to life. Cool!

Our favorite personality trait of the new RM-Z250 is the way it handles. With a lower center of gravity than the YZ250F, the Suzuki has a very nimble, agile feel on the track. The bike has a very lively personality in all conditions, and can be cranked over in a loamy corner just as well as it can be slid through a flat, dry turn. In the air, the bike has a much more maneuverable feel, thanks to its small, compact layout and low center of gravity. While the Yamaha feels as if it rides between your thighs and knees, the Suzuki feels as if it is between your knees and boots. In rough conditions, all of our testers were stoked on the way in which the RM-Z handled, though it has a slight twitchy feel in high-speed situations.

Suspension action on both ends is good, but plan on investing in a revalve if you are out of the target weight range of 150 or so pounds. Once our Suzuki's fork and shock broke in, most of our testers found themselves wishing for stiffer springs and/or a higher fork oil level. The rear end of the bike is super predictable and inspires plenty of confidence in square-edged kickers as it always tracks straight and true. The forks, meanwhile, are equally adept at gobbling up the track's imperfections, but did prove too soft on hard landings, even for our lighter test riders.

Ergonomically speaking, the RM-Z has a very small, compact feel, especially at low speeds in the pits. The seat height feels quite low in relation to the handlebars, but at speed on the track, this becomes less notable. Still, we plan on experimenting with taller seat foam to see if it gives the bike a more “on,” rather than “in” feeling. At the mid-section, the RM-Z is nice and thin, even for a four-stroke. This isn't your daddy's DR-Z!

Brake action and strength is superb on both ends, and we particularly enjoy the feel and modulation of the front binder. Adjustable at the lever for riders with smaller hands, the front brake has exceptional strength and a positive feel.

All in all, the 2004 Suzuki RM-Z250 is an exciting, competitive machine that is sure to make the 125cc class more interesting. Though there will always be two-stroke die-hards, its getting harder and harder to imagine choosing a pipey 125 when there are awesome bikes like the RM-Z250 to choose from.

CAPTIONS

BIKE SHOT

With its perimeter frame and full-coverage radiator shrouds, the 2004 Suzuki RM-Z250 doesn't look much like the rest of the Suzuki RM lineup. Why? While Suzuki developed the RM-Z and KXF engine, the engineers at Kawasaki researched and developed the chassis, suspension and body work. The result is the first jointly engineered bike that has resulted from the recent Kawasaki and Suzuki merger. We love it!

ACTION SHOT

The Suzuki RM-Z boasts incredible throttle response and quick, nimble handling characteristics that help the bike to shine on tight, technical tracks. TWMX's senior test rider Rich Taylor puts the RM-Z through its paces at the Glen Helen Racing Enterprises race track.