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.