PHOTOGRAPHY BY KIT PALMER

Great bottom-end makes blasting out of tight corners with soft berms as easy as just rolling on the throttle.

Great bottom-end makes blasting out of tight corners with soft berms as easy as just rolling on the throttle.

Like its little it brother, the Suzuki RM-Z450 received the exact same list of changes for 2014, which really isn’t much of a list at all: The former white side number plates are now yellow and the ECM ignition programing has been altered to improve starting. There you have it.

But the RM-Z450 did get everything but the kitchen sink thrown at it last year. It was the first significant upgrade for the RM-Z450 since its last major revamp (when it got fuel-injection) in 2008 - so we’ll cut Suzuki some slack for going light on the RM-Z450 this year (2014). Luckily, it was already a good machine. Big-time motor and chassis mods last year made the 2013 RM-Z a big hit with most people, including us, but we struggled a bit with the RM-Z’s suspension, mainly up front. We just could not get completely satisfied with the new Showa Single Function Fork (SFF), which might’ve had something to do with some of the frame changes it got last year. As a result, the bike didn’t fair as well as we thought it would in our 2013 450cc motocross comparison test. We just couldn’t come to terms with the front end and could never quite get the fork completely dialed in to our liking during our allotted shootout time schedule – we can give only so much attention to each bike to keep things fair and square and the Suzuki might’ve been the victim because of it. (We never got the chance to ride the bike again after our shootout.) But that was last year.

So, we were quite anxious to spend some time on the new RM-Z450 when Suzuki recently held a two-day press launch of its 2014 250 and 450 RM-Zs at Perris Raceway in California, as we could finally give the RM-Z our undivided attention. Our main focus on the 450 was on the RM-Z’s SFF fork. After all, the entire Suzuki crew and suspension experts were present, so what better time to get things figured out than now?

The RM-Z450 is still the king of the turns.

The RM-Z450 is still the king of the turns.

At first, we pretty much experienced the same front-end feel on the 2014 RM-Z450 as we did with last year’s bike. Initial stroke of the fork again felt harsh, giving the rider too much feedback in the arms, and the mid-stroke wouldn’t hold the fork up high enough, especially under hard braking, which caused the front end to twist slightly. Once the track developed big enough bumps that we could actually feel, Suzuki’s suspension wizards suggested we add one click (stiffer) to the preload and take two clicks out (softer) on the compression. By adding to the preload we put more tension on the fork spring, allowing it to ride higher and provide a better feel down low in the stroke. By softening the compression we made the initial ride plusher, which came as a relief on our hands and upper body. Those settings did, in fact, work much better, but we weren’t done yet. By changing the fork, the shock also needed some attention. Here’s the trick: We found that by going one click stiffer on the shock’s compression to get the rear end to ride higher in the stroke, and one click slower on rebound to slow down the up force, it helped to match the action of the new fork settings. We also stayed with Suzuki’s recommended 105mm ride height. Finally! Everything seemed to come together, so maybe our problem last year was more with dialing in the shock than the fork.

These few changes yielded a bike that not only felt really good in the corners, but also had an overall softer, well-balanced and stable ride. The fork’s initial stroke was noticeably plusher yet the mid-stroke held up better down the straights, and the twisting from the front end under braking was put to rest. The sensitivity to adjustment of the Suzuki’s SFF fork was something that we didn’t take as seriously as we should have on the 2013 model, and more times than not, we found ourselves lost in the settings like an episode of the Twilight Zone. The shock itself has always been solid, so with the correct sag and a few clicks to enhance the front of the bike, it all came together nicely. However, there is still room for improvement in the suspension department and we’re anxious to try out the bike on another track, but we are happy to have found what appears to be a good base setting, both front and rear. Now we could enjoy the rest of what the RM-Z450 has to offer, like the motor.

The Showa SFF forks are ultra-sensitive. Each click on the adjusters make a noticeable difference.

The Showa SFF forks are ultra-sensitive. Each click on the adjusters make a noticeable difference.

The motor package is excellent. Power is solid across the board, but bottom-end is where it really shines. There is just enough low rpm grunt to shoot you out of the corners and onto the next obstacle in an instant without being violent. Mid-range power is also impressive. There is plenty of it and is long and broad, allowing you to pull third gear for quite some time without compromise. Top-end is plentiful, too, but unless you’re at a National-style track (i.e. long straights and hills), you probably won’t be hanging out there much anyway, not with the RM-Z’s excellent bottom and mid power delivery at your disposal. But top-end is certainly there when you need it.

Like the 250, the 450 utilizes three pre-programmed couplers to alter fueling and ultimately power characteristics. We stuck with the stock coupler all day; it seemed to work well with the Perris layout and dirt, so we felt no immediate need to change it out on this day, but we will experiment more with the leaner and richer couplers another time.

Clutch pull is sufficiently light and we experienced only slight fading throughout the day, even in 95-plus-degree SoCal temps. Like last year, the transmission’s gear ratios work in harmony with the bike’s top-to-bottom power delivery, and shifting action is smooth and positive, although finding neutral while the bike is running is still a little tricky.

Starting didn’t really feel any different than we remembered, but we don’t recall having any issues with starting the bike last year anyway.

The 2014 RM-Z450 carries over all of the major changes it got last year. No major changes were added.

The 2014 RM-Z450 carries over all of the major changes it got last year. No major changes were added.

Cornering has always been the Suzuki’s strongpoint and it still is, especially when you get the suspension dialed in and balanced. The front-end tracks very well and steers light, and rarely does the bike want to stand up in the ruts. Like the 250, the 450 is a point-and-shoot machine while still maintaining excellent straight-line stability.

In short, the 2014 RM-Z450 is the same bike on the track as the one it replaces, which means that it is no slouch. We’re stoked to get a better grip on the Suzuki’s suspension this early in our testing, unlike last year, so we’re anxious to match it up to the all-new Yamaha YZ450F, the slightly updated Honda CRF450R, the retouched KTM 450 SX and the unchanged Kawasaki KX450F, our defending shootout champ, in our upcoming annual big-bike motocross comparison.

By Jason Abbott

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