Suzuki has received a fair bit of attention due to the fact that neither of its major motocross bikes made it into Dirt Rider shootouts this year, and we've received quite a few queries from Suzuki fans as to what the deal is with Big Yellow. Both of Suzuki's flagship moto machines are, in fact, alive and well, and as of now we've finally been able to give the 2010 RM-Z450 a shot. Here's how it all breaks down:
Although relatively unchanged compared to the previous model year, Suzuki did apply several revisions to the 2010 RM-Z450 in order to fine-tune the performance of the bike and fix a few minor issues from '09. At the top of the list of changes are tweaks to the bike's fuel injection, as the throttle movement has been flipped around so that the butterfly valve now opens in the opposite direction to give the response a smoother feel. There are now two preprogrammed EFI map settings-one for standard conditions and one for higher humidity (leaner)-that are accessed via a coupler under the number plate. Inside of the motor, Big Yellow has come up with new intake and exhaust cam shapes, which are designed to boost power. Additionally, the RM-Z has a reshaped intake tract for more power down low, as well as softer exhaust valve springs. The cam-chain tensioner has been redesigned for decreased vibration, and the kickstart lever has been slightly modified as well. On the chassis side of things, minor portions of the RM-Z450's frame were altered to provide better balance and flex. The frame's headpipe was increased in length by approximately 9mm for added rigidity, so call it a new frame. The spring rates for the suspension were cranked up just a tad in both ends. While the sum of these revisions don't add up to a drastically altered bike, it's clear that Suzuki didn't just slap new decals on its '09 RM-Z and call it a 2010.
Perhaps the one benefit to receiving this bike so late is that we had already ridden everything else, and as such it was fairly easy to distinguish the various character traits of the Suzuki to see how they fit into the hyper-competitive 450cc class. The first major highlight-something that jumped out at nearly every tester by the end of their first session on the bike-is the RM-Z450's superb power delivery. Whereas some of the other bikes in this class feel as though they are shoving power down your throat by the fistful, the Suzuki serves you power like a well-trained waiter pouring a glass of fine wine. Is it mellow? To a degree, as there isn't any violent hit to speak of when you twist the throttle from a slow roll. But this 450 is far from wimpy, and you can certainly tell it means business when you get on the gas. A strong low-range pull steadily becomes a meaty mid that seems to last forever, while the top-end continues further than that of any previous RM-Z450s, which is a marked improvement in our book. Sure, the bike will sing up top if called to, but we don't think there's any reason not to ride the bike in the crisp upper-mid range. At this rpm and in the revs leading up to it, the usable acceleration translates directly into good traction, predictable shifting and pure ease-of-use. You can easily stick the RM-Z into third gear and do an entire moto while hardly shifting or touching the clutch, something that is a blessing toward the end of a long, tiring moto. The well-tuned EFI ensures there aren't any bobbles off idle, and the altogether usable powerband was a fine fit for testers of all abilities.