Honda CRF450X Moto Conversion - Dirt Rider Magazine

Just two quick stories (among many) that motivated this project: At an open track day we saw a Honda CRF450R pilot with the rear shock travel shortened four inches. Why? So he could reach the kickstarter! Second, on a Baja ride with Malcolm Smith two guys on off-road-converted CRF450Rs missed all of the good single-track section. Why? The bikes were geared too tall. In both cases their bike choice was justified with: “We like to ride motocross.” In both of these scenarios, the riders would have enjoyed riding much more if they had started with an off-road model like the Honda CRF450X.Many riders now mix off-road passion with MX thrills. For some it is a winter/trail, summer/track deal. Others choose track when time is of the essence. If you are planning your own do-all ride and you do anywhere near 50/50 off-road/moto, at least consider starting with an off-road model. We set out to prove it is a viable option to amplify fun and minimize cost. Going in we didn’t want to bust the budget or ruin the bike for off-road playing or racing.After the 2010 pipe test (August ’10 issue) we knew the 2008-’09 (Honda didn’t make a 2010 model, but sold ’09s) CRF450X could have a fun, responsive MX feel on the trail, so we first rode the bike on the track stock with just an FMF Q4 muffler and a PowerBomb header. The lean jetting we noticed during the pipe test was bothersome on the track, so we installed a JD Jetting kit and followed the JD instructions on opening the airbox. With the kit installed the fun factor jump was huge. Since the bike was going to spend a lot of time on the track, we swapped the Q muffler for FMF’s 4.1 motocross muffler (with the 94-decibel tip). We thought the off-road power delivery and gearbox spacing would be a problem on the track, but the power is the best part. You can feel there is a wider gap from second to third, but the smooth yet high-torque-feel power pulls the spacing easily. Third gear is a bit lower than a Honda CRF450R. Even when the track is wet and slippery the X engine hooks hard and literally carries the front wheel for entire straights and especially up hills. The total high-rpm power is down compared to any modern 450 MXer, but the overall acceleration is fine. This is power that is easy to use and does not tire the rider.The suspension worked well on mild tracks with surprising bottoming resistance when landing a bit short. Since the bike went to the smaller 1.9-gallon tank and HPSD steering damper in 2008-’09, it came with suspension settings boasting improved plushness in slow, choppy off-road use. Despite the improvement on the trail, the suspension is still capable of handling the big impacts of MX. The action is super plush on braking chop, and the wheel control is impressive, but faster tracks with abrupt G-outs or slammer jump faces ate up too much travel for comfort. We took a two-pronged attack on suspension. First, we swapped to a 19-inch rear wheel and tire and got much better suspension feel on acceleration chop as well as better control and traction. The 19-inch squirms around less on packed surfaces and does not bounce while braking into corners. Next, we had Pro-Action modify the suspension with stiffer fork springs and valve shim and piston changes. We asked for a setting that would still work off-road, and the action remains supple on the track but control is much better. For aggressive moto guys or G-out tracks the bike would work better with a no-compromise MX setting, but we got exactly what we wanted in terms of action and wheel control, and it was still fine off-road.