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2007 Suzuki RM-Z450 Dirt Bike – First Test – Dirt Rider Magazine

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Tuesday, February 24, 2009

Ryan Orr/></a> <p class="wp-caption-text">Ryan Orr</p> </div> <p>Since this is the bike that is winning at the highest level, does that make it the best bike out there? Or is Ricky Carmichael’s bike so different and RC so talented that it doesn’t matter? One thing is for sure: With a production rule in place, at least the base has to be good, and Suzuki knows this. And it has that covered.This looks like a revision year for the RM-Z450, with most of the attention going to the 250F. We wouldn’t call all the changes minor, though, since there is an all-new frame, but the length of the list is short. On the engine side, some tuning for low-end and midrange made a notable difference to our test riders. It feels like the RM-Z comes on earlier, still possessing that chuggability on the bottom, and the power is better filled into the midrange. It makes the bottom and mid feel less impressive only because it is smoother and transitions better without unwanted hit. You can get pretty crazy with the RM-Z throttle, and instead of getting out of control, you get good solid power. The top-end pull isn’t going to win any awards for total amount of peak power, but it ranks way up there in terms of usability. It revs far and pulls into the rev-limiter. It’s far from slow on the track; it hooks up with all the power the tire can handle and propels the bike just right. We did have to tune the fuel screw quite a bit (when the bike popped in zero-G bumps, we went richer), and our bike liked a 172 main jet, which definitely made it pull better on the top. You never have to use the marvelous clutch to control the power and rarely have to coax more power out of the motor, but when you want to pull a gear high through a turn, it is easy to manage. The shifts on the four-speed are smooth, and the length and tuning of the power go hand-in-hand with the tranny spacing. Suzuki took a step in the right direction by relocating the oil pump and its screen filter for more efficiency (less drag on the engine) and ease of maintenance-access without splitting the cases! And there is now an automatic cam-chain tensioner this year, which is simply mindless for the owner, and all of the engine’s mechanical racket is gone.Combining into a well-matched one-two punch is the chassis. The frame spars are thinner and the lowers have more wall thickness, changing the chassis rigidity. Could we feel it? Not exactly, but what we did feel was better, sticking all the way through turns and offering great hookup exiting in chop or bumps. We’ve liked the RM-Z for its turning, and this one is only better. The bike still feels a little wider than some of the other 450s, but the steering feel is very light, even with the larger 90/100 front tire. The RM-Z can feel a little heavier when jumping or getting bucked around-but not by much-and it feels a little lighter in this way this year. It is really easy to move around on the bike. The seat is actually pretty cushy, and we like the gripper material on the sidewalls of the seat cover.Suspensionwise, it seems the Showa components got the right internal changes to cooperate even better with the chassis. While not the plushest suspension around, it seems Suzuki got better damping control from inside, especially for the big hits. Bottoming resistance is better, and we never got the loose-rebound or blowing-through-the-stroke feeling. We set the sag near 100mm, and most riders were happy, though some thought the bike was actually packing a bit, mostly hitting bumps coming into turns. We’ll definitely be tuning on this coming into shootouts. One trait of the Suzuki that we liked was that when it used up some of its travel, the RM-Z grew long and stable and very confident. Whether it was bouncing through bumps or pushing the bike into turns, it preferred being raced hard.So where does it stand? This is a better and more refined RM-Z, for sure. Suzuki addressed a lot of the weak points of the bike. When its pieces are examined individually-e.g., no insane power, not the plushest suspension-the ‘Zook may not stand out as impressive. But looked at as a package, the RM-Z is a really good ride that gets around the track fast with little fuss. Come comparison time, the RM-Z450 may impress us. <div><a href=

Opinions

The RM-Z has the same basic, predictable feel as the ’06 model but with added traction on acceleration. The bike would never skate away, anywhere. Although in stock form it has some of the same settling issues coming into braking bumps as last year, I felt that the rear was a little soft and was packing. With a little more time and some suspension tuning, I’ll bet that problem will disappear. Once you get the bike to drop into the wave of dirt that we call a berm or rut, the RM-Z is unstoppable. As a matter of fact, it could be a flat turn-it finds traction everywhere. The motor is also an improvement, with a minor bump-up in power off the bottom plus an increased usable midrange. It was definitely hard to stay forward on the seat. As a pro, I could use a little extra up top. It didn’t run flat, but it didn’t really have that crazy top pull near the rev-limiter, either. But a smart rider could still rip by short-shifting the bike and using the meat of the motor where it is good. Then there would be no point trying to find the rev-limiter.
-Ryan Orr/5’10″/170 lb/ProStarting off from a smooth, solid low-end, the RM-Z’s motor doesn’t hit violently, but it still has a powerful pull that reminds you why it’s called a 450. Revving the bike into the midrange showcases a dose of incredible traction, with the rear tire never failing to make a footprint. The Suzuki can be slid into or out of just about any corner, and the power somehow always manages to find the ground. For my ability and weight, I thought the motor presented a lot of ridability without wearing me out too much; it is somewhat of a gentle giant when it comes to delivery, but you still have to be prepared for the generous amount of available horsepower. Ergonomically, the Suzuki’s footpegs feel a little far back at first, but this actually set up my 5-foot 10-inch frame in a great standing riding position. The brakes are solid, and I am yet again a fan of the stock Renthal handlebar. After a day of testing the ’07 RM-Z, I can easily say that it has one of the most usable motors of any stock 450 I have ridden recently. Only time will tell if Big Yellow has it in her to win our upcoming shootout, but I definitely think she has a swinging chance.
-Chris Denison/5’10″/155 lb/IntermediateI can pick this bike apart piece by piece, but when I ride it, the thing hauls around the track and is really confidence-inspiring. It is one of those bikes that you should just twist the throttle and quit thinking about it-the bike gets the job done and pretty fast, too! My only concern about buying one would be that the suspension may loosen over time, though I’m sure a suspension shop could cure that. The clutch is magic, the bike is great going in, through and coming out of turns, and the power is easy for me to time jumps with. On the track, the four-speed gets the job done. If you are a Suzuki fan, you won’t be let down one bit by this RM-Z.
-Jimmy Lewis/5’10″/185 lb/Vet ProSpecifications

MSRP: $6799
Claimed dry weight: 220 lb
Weight (ready to ride, no fuel): 235 lb
Seat height: 37.3 in.
Seat-to-footpeg distance: 20.6 in.

What’s Hot

  • Suzuki did all the right tweaks to the RM-Z.
  • A powerplant that didn’t just go for bigger numbers; the Suzuki engineers went for a better delivery.
  • Great turning.
  • Improved ease of maintenance.

    What’s Not

  • Suspension feel could be plusher.
  • Makes more engine noise than other 450, and drive-chain slap is noisy, too.
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