Honda CRF 450X

A motocross-inspired, enduro-ready four-stroke machine
Ryan Dudek
April 2005


The wait is over. Well, just about, anyway. It's been three years since the CRF450R was introduced, and now Honda has taken the number-one motocross bike (a Cycle World Ten Best winner three years running) and turned it into a full-fledged enduro machine.

Understanding that off-road riding and racing differ drastically from closed-course motocross competition, Honda's engineers took their sweet time to make sure everything was perfect. Virtually every single component from the CRF450R was changed to meet the unique demands placed on the CRF450X. Sure, you could take a motocross bike, add an electric starter, lighting system, flywheel weight and a set of wider gearbox ratios and then head to the hills. It might even be a great bike—but it surely won't be at the apex of off-road performance.

Where do we start? How about with a Honda test rider stuck in a ravine on a 450R, goggles off, sweat poring off his brow under the burning sun, kicking, stalling, kicking? It didn't take him long to realize he couldn't use the relentless power of a motocross bike off-road; if only he had an engine with a little more midrange punch and friendly, tractable power to boost him out. An electric starter wouldn't hurt, either. Maybe it was cross-country ace Scott Summers wrestling a 450R or XR650R through the woods during a three-hour GNCC race, all the while dreaming of a bike with better bump absorption and plusher suspension to deal with the endless bumps, rocks, roots and dips? Or was it desert fireball Johnny Campbell pancaking his XR650R over a 5-mile stretch of whoops en route to another Baja 1000 victory, imagining what he could do with a lighter, more agile bike?

However Honda came up with the idea, the important thing is it succeeded in achieving its goal.

Besides lights, kickstand, electric starter, etc., one of the reasons for the X's added weight is this coolant catch tank that usually hides behind a plastic skid plate. MX version vents to atmosphere.
How different is the X from the R? Only a few pieces carry over between the two. Adapting the R's twin-spar aluminum frame wasn't a simple use-the-same-part idea. The engineers' mission was to create an off-road frame with the same handling confidence found on the motocrosser, so the lower frame rails have .5mm-thicker walls, the steering-head casting is new, the front frame joint is different—even the gussets have changed in size and shape. All this helps to make the bike less rigid (for better feel and feedback on trails) while still keeping its high-speed stability and tracking ability. Mission accomplished!

It's not only the frame that gives the X its superb handling, but also the 47mm inverted Showa Twin Chamber cartridge fork derived from the R. The fork uses settings unique to the X and has 12.4 inches of travel, giving you plenty of cush for most any obstacle. In back is a Pro-Link system featuring a fully adjustable Showa shock, also providing 12.4 inches of wheel travel. The aluminum swingarm features a double-taper design with a large, cast-aluminum cross-member for high strength and light weight. Putting the chassis to the test on tight trails and wide-open graded dirt roads, we never had any handling


Of course, Honda engineers didn't stop with the chassis. They completely changed the 450R's engine to create a spread of power better suited to off-road use, while also adding conveniences and durability. The X version keeps the same basic architecture and layout as the R, with a displacement of 449cc and Honda's innovative Unicam four-valve head, just with numerous changes to enhance off-road performance.

Intake and exhaust valves are 1mm smaller in diameter to increase intake-charge velocity, thereby improving throttle response. The attachment of a much-desired electric starter dictated the creation of all-new engine cases, followed by a revised cylinder, head and camshaft that mirror the CRF-R's design. Another big change is a wide-ratio five-speed gearbox that's tougher than ever. More mass was added to the AC generator and flywheel for improved low-speed tractability, although we feel it could use a little more mass for extreme conditions.

Unfortunately, all these changes have added weight to the overall package. Our testbike weighed-in 30 pounds more than the motocrosser. But the engineers put their heads together and came up with ideas to put the weight where you can't feel it-in the lowest possible places. So you'll find the coolant tank neatly tucked away under the engine and protected by the skid plate. A little higher up is the electric starter that uses neodymium magnets (also known as "rare-earth" magnets) allowing the starter to be smaller and lighter than the one on the 2004 CRF250X.


One quick look tells you this machine is off-road-ready. It comes standard with an 18-inch rear wheel, 2.27-gallon gas tank, powerful new 35-watt halogen headlight, tiny LED taillight integrated into the rear fender, easy-access air filter, removable kickstand and a USDA-approved muffler/spark arrestor. Some of the unnoticeable items include larger radiators, a wider seat with rounder edges and 240mm front and rear brake discs. Californians rejoice, because the CRF-X is Green Sticker-legal, meeting CARB's strict emissions standards.

Minor Complaint Dept.: The CRF450X has everything you'd want in an off-road machine except two, a pair of handguards. Without them, bushes and trees have a tendency to grab levers at the most inopportune times. Otherwise, there's nothing this bike can't do. Uphill or downhill, over rocks, stumps, trees and whoops, through streams, creaks and gullies...you name it, the 450X does it all, and pretty darn well, too. It feels like a 250X, only with a lot more power to carry you along the trail. This enduro model is everything we expected, if not more. Will it be enough to overtake last year's Ten Best winner, the Husqvarna TE450, as 2005's Best Enduro Bike? We'll find out as soon as we can wring them both out together. Stay tuned.