Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/1545838
D on't let Honda's early release of the CRF450R fool you: The king of the big-bore (or motocross, Supercross, 250, 450F, Open, etc., whatever you want to call it) class has changed. Okay, maybe it didn't get a complete makeover like the Yamaha YZ450F got last year, but the CRF450R didn't need one. It did, however, take on enough sub- tle changes to keep things somewhat interesting. When it comes to the CRF450R, every year we wonder what Honda can possibly do to it to make it better, and every year they surprise us by somehow finding a way. One fail-safe method of improving any motorcycle - no matter how good it is, such as the Honda - is to give it more horsepower; after all, no one ever complains of having too much power. So Honda went searching for more muscle from the already-potent 449cc, Unicam, four-valve motor; which, by the way, has reached the 100,000 plateau of Unicam-powered CRFs sold since the 450's debut in 2002. (Thought we'd mention that since Honda was quick to point that out to us; obviously, they're proud of their Unicam motors.) Just as we were, and just about everyone, Honda was already quite pleased with the '06's power char- acteristics, but for '07, they wanted more power across the board. The trick, however, was to get that extra oomph without tampering with the CR's already highly praised power delivery. Honda started at the bottom. To get more grunt down low, plus more pulling power in the middle of the powerband, they replaced the 31mm exhaust valves with smaller 30mm valves, and they reshaped the exhaust and intake ports. And to keep the power curve balanced, they fitted the CR with a larger 41mm (from 40mm) Keihin FCR carburetor to get more power on top. To improve throttle response, the CR got a new accelerator pump and linkage, as well as new ignition mapping. What Honda came up with it says is more power across the board but deliv- ered in the same manner as before. Can this true? Yes. Believe it or not, the '07 CR motor is improved - maybe not drastically, but it is noticeably better. We found the new CR to perform as promised, having better-pulling power off the bottom and throughout the entire rev-range, all the while still feeling like - well, like a Honda CRF450R. Despite having more pulling power and torque (at least that's what it feels like, having yet to put the bike on the dyno), the Honda actually seems a little easier to ride overall, because, in many situations, you can now leave the bike a gear higher, which means less shifting and more momentum carried around the track. On top, the Honda is just plain fast. Real fast. Almost scary-fast. The upper rev range is best left for the Kevin Windham's of the world, because stuff starts happening really quick up there. For most peo- ple, however, the bottom to mid window is wide enough to perform most of your on-track business while feeling reasonably in control. So, in other words, the Honda will work with a wide range of skill levels because you don't have to keep the CR pinned to make it go fast. Honda also beefed up the clutch a bit. The clutch basket now has more silicon content to make it hard- er and stronger. We've already spent quite a bit of time on a sand track on the CR and experienced zero slippage. After thoroughly scrutinizing the '06 CR, Honda found that it could save some weight by making the JULY 26, 2006 • C Y C L E N E W S 38 STORY AND PHOTOS BY KIT PALMER 2007 Honda CRF450R A new linkage-type front-brake lever yields more mechanical leverage. The result: better feel and less effort.