Despite few, if any, changes over the past couple of years, the Suzuki RM-Z450
has been one of our favorite mounts for a day at the MX track. Even so we felt the big ‘Zuk was getting long in the tooth and were ready for a change from Team Yellow. When the 2013 RM-Z model press release hit our inboxes you could almost hear the collective yawn echo through the So-Cal office. But then we read further and our despair turned to hope. Although the 2013 model looks almost identical to the 2012, it’s what under that yellow and black plastic that matters. Would our first outing on the latest RM-Z450 be everything we hoped it could be?
decided to invite the press to sample the 2013 RM-Z at its private Supercross test track in Corona, California. A questionable move on their part? How could mere mortals such as ourselves ride the very same dirt that Brett Metcalfe shreds to prepare for his SX season? Even our always-stylish ringer, Matt Armstrong, was sweating bullets, as he would be hitting the road for his wedding just a few days later. On arrival our fears were diminished when we were greeted with a reworked and tamed track that resembled a state fairgrounds race track rather than something that could break us in two. So it was time to get down to it, but first – the technical details.
As mention earlier, it would easy to mistake the 2013 Suzuki RM-Z450 for a 2012 model, but subtle (very subtle) visual cues
The 2013 Suzuki RM-Z450 gets the second generation of Showa's SFF fork.
set it apart. A yellow front number plate and black rear fender are the most noticeable changes to the look of the RM-Z. Bold new graphics finish off the visual aspect. A change to the bodywork that isn’t easily seen is narrowing of the radiator shrouds at the junction between the seat and tank area for a flatter transition between the two to make gripping the bike easier.
The only other visual clue of changes on the RM-Z is the red anodized fork caps. For 2013 Suzuki has added Showa Separate Function Forks to the front end, but these are the second generation of this design. Various changes have been made to the second-generation SFF units. Most notable is the larger size of 48mm (from 47mm) for increased rigidity and smoother operation. Just about every internal part has also been enlarged by one to two millimeters for even more strength to lessen the flex discrepancy between the left and right fork. This increases stability during braking and hard landings. The spring stack in the right fork has also been inverted to give it a plusher feel while still being stiff for heavy landings. Out back the changes are not as drastic with just a change to the size and shape of the rear linkage bolts from 12mm to 14mm for easier maintenance and better bump absorption.
The aluminum chassis received a few tweaks as well in an effort to improve side-to-side handling. Suzuki’s engineers changed the shape of the motor mounts to make the frame and motor relationship stiffer. Then the lower subframe connection was altered to firm up the flex characteristics and improve rider feedback from the rear suspension.
The 2013 Suzuki RM-Z450 gets a new piston, intake camshaft, reshaped transmission gears and muffler.
Internal updates are numerous. The piston has been lightened by 13% without sacrificing any strength while the connecting rod is lighter as well, combining for a 9% overall reduction in weight. Additionally, the piston pin gets a DLC (Diamond Like Coating) treatment. In a search for more mid-range and easy-to-control power the intake cam gets a new profile with more lift. To complement the new power characteristics and to conform to FIM sound levels the internals of the muffler have been changed, and the end cap is held with bolts rather than rivets to facilitate easy changing of the muffler packing. On the intake side, the airbox has also been modified to increase the bottom to mid-range hit while quieting intake noise.
The transmission also got an overhaul with the reshaping of 2nd, 3rd, 4th and 5th gears for more precise gear changes. The shift cam and stopper plate also received attention to boost the shift feel. Finally the countershaft sprocket is now held by a bolt rather than a circlip to better control the load from the suspension and traction forces on the driveshaft.
Powering the electrical system, the magneto output has been increased by 8% to power a higher output ignition coil and for quicker starting. New ECM settings double the ignition energy with higher processing performance. The location of the interchangeable EFI coupler has been moved from behind the front number plate to beneath the left radiator shroud.
Suzuki’s engineers really went through the RM-Z450 with a fine-toothed comb and added a host of updates to improve the durability and maintenance of the big yellow racer. Dust covers were added to the front and rear hubs, a spacer was added to the front brake hose clamp, and the steering head dust cover material was changes in an effort battle the dust and dirt. Inside the engine the camchain guide has been reshaped to increase its rigidity and life. The lubrication system gets a new crankcase reed valve that improves efficiency but also smooth out throttle response and power delivery. A strong magnet has been added to the oil strainer pipe to capture more metallic sludge, further enhancing the oiling performance.
The powerband has been broadened on the 2013 RM-Z450 and the EFI can be fine-tuned with different couplers.
As you can see, the changes between 2012 and 2013 are quite significant for the RM-Z450, but it doesn’t mean squat if all that work doesn’t translate to a better machine on the track. Kicking over the engine doesn’t really seem to be any easier than before, but it usually fires in the first two or three kicks which is average for 450 MXer.
Once on the track the RM-Z’s power has been broadened, but on the super compact test track it was difficult to tell what effect the fatter mid-range had on the top-end. Novice and intermediate riders will appreciate the usable spread of power from the 2013 as it requires less shifting on shorter tracks. We had the chance to play with the different EFI couplers and the difference from the stock setting to both the leaner and richer maps was marked. Our test rider Matt felt the stock setting was the best for the short and tight track, but the ability to change the maps so quickly is a great feature. He liked the hit of the lean map for more pop, but this also made proper throttle control more important.
The SFF fork is plush, but to be fair the meticulously prepped track was super smooth with no braking or acceleration bumps to be found. Front-to-rear balance is excellent and the rear suspension settings complement the new fork. Matt over-jumped a few times but never had a problem with a harsh landing. The fork is very progressive and feels almost bottomless.
Handling-wise the RM-Z450 feels very similar to the 2012 model. Transitioning from left to right is quick and easy, and dropping the bike into a turn takes just the right amount of effort. Once in the corner the Suzuki is stable and planted without any tendency to stand up or flop down. High speed stability is a question mark as there weren’t any fast parts of the track, but we expect that it will be on par with the 2012 which was one of the better machines in our 2012 450 Motocross Shootout
The Suzuki RM-Z450 is a very competitive racer and gets even better for 2013, but we would still like to see an all-new machine soon.
Ergonomically, the 2013 RM-Z450 feels identical to the 2012 model, which for most is a good thing. The cockpit is roomy with nothing being out of place. The handlebars are the only part of contention with our staff. Some of us love the RM-specific bend Renthal bars, while those that prefer a straighter bar absolutely hate them.
On such a tight track, getting slowed down is imperative and the RM-Z’s stoppers got the job done with excellent feel and power. They may not be high-end Brembo units, but we had no problems with fade or a grabby feel all day. The initial bite is not too strong, but the power available from the front lever is strong.
After a day at Suzuki’s private test track, we were left with a positive impression of the 2013 RM-Z450, but even with all the changes we weren’t blown away. There is no doubt the RM-Z is near the top of the food chain in the 450 class, but perhaps it feels too familiar and not new enough to leave us raving. It’s a better bike for sure and will be a potent weapon at the track with it’s new-found mid-range and upgraded fork. It’s the next level with the current design of the RM-Z, but to be brutally honest we are ready for an all-new version from Suzuki. We think everyone is, but the 2013 RM-Z450 is more than enough of a performer to hold us over until that happens.
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449cc, 4-stroke, liquid-cooled, single cylinder, DOHC
Bore x Stroke:
96.0mm (3.780 in) x 62.1mm (2.445 in)Compression Ratio:
Wet multi-plate, cable actuation
Showa Seperate Function (SFF)telescopic inverted, coil spring, oil damped
Showa link type, coil spring, oil damped
240mm disc, double-piston caliper
240mm disc, single-piston caliper
Bridgestone 80/100-21 M403, 110/90-19 M404