Honda has an all-new, genuine competition-ready enduro machine in its off-road line up – the CRF450RX. And it uses the engine and chassis package of the 17YM CRF450R as its base – Honda’s first totally new 450cc moto-crosser in eight years.
The Honda CRF450R has been a benchmark since its introduction in 2002. It has defined the art of balance, with an engine that produces hard-hitting, useable power and a chassis that allows the rider to put every drop of that power to good use. It has always been a machine that offers total control, together with the stability and durability that Honda has long been famed for.
This makes it the perfect platform on which to build an enduro machine, giving the CRF450RX both the pure moto-cross DNA to deal with any special enduro stage and the confidence-inspiring competence to handle flat-out trails, challenging climbs and tight, tricky sections with ease.
The CRF450RX is something truly special, not just for Honda, but for the enduro world to ride and race. It looks different and feels different to the rest of the pack. And, just like the new CRF450R, it is compellingly fast.
The new CRF450R has been built from the wheels up based on direct input from AMA and European MX teams, and packs a power to weight ratio 11% better than the outgoing design. The CRF450RX is identical in almost every area, but has some crucial changes to create an uncompromising enduro focus.
Both front and rear suspension are less firm, with lighter compression damping and a lower spring rate for the shock. It uses an enduro-standard 18in rear wheel, and sidestand and 8.5L fuel tank was also added for practicality and extended range.
The CRF450RX’s PGM-FI ignition timing map produces softer power and torque delivery than the CRF450R to aid traction feel in awkward conditions. As on the CRF450R, the EMSB (Engine Mode Select Button) provides the rider with 3 distinct choices: Mode 1 equals all-round smooth performance, Mode 2 gives the most easy-to-manage throttle feel, and Mode 3 delivers the power in the most aggressive, responsive way. Electric start is fitted as standard.
The CRF450RX’s 449cc engine shares the specification of the new CRF450R engine, which has received an 11% boost in top-end power for 2017, while still offering its trademark progressive, usable power and torque delivery throughout the range. Compression ratio is set at 13.5:1 with bore and stroke of 96mm x 62.1mm.
All five gear ratios are the same as the CRF450R, but with final drive handled by 13- and 50-tooth sprockets (as opposed to 13/49).
The rider controls and displays are rationalised together and sited on the left handlebar; EFI warning, plus EMSB mode button, LED indicator and engine stop/start button for the standard-fitment electric starter, which makes restarting a stalled engine much easier, especially on tracks with rocky, uneven surfaces.
Honda’s EMSB puts instant engine character adaptability at the rider’s command. With the machine stopped, and engine at idle, a simple press and hold of the button for just under a second selects the next map in sequence.
The LED built into the button signals the map in use with a quick press and number of subsequent flashes (1 flash for Mode 1, etc). If a new map is selected the choice is also confirmed to the rider.
Mode 1 is the base map and provides the most linearity in throttle response, making the engine’s power much more usable in a wide range of conditions. Mode 2 tones down engine performance (especially useful for a tired rider) while Mode 3 delivers the power in the most responsive way – with a delivery similar to the standard mapping (Mode 1) of the CRF450R.
This is a full competition engine and needs regular maintenance. Service intervals are straightforward however with oil/filter changes and valve clearance checks every 15 hours. The engine does not need to be totally stripped and rebuilt after a certain number of hours’ use.
The CRF450RX uses the seventh generation CRF aluminium beam frame with improved turning performance, front-end stability and traction. It also delivers greater rear wheel drive with elevated levels of rider feedback and predictability.
Several subtle changes to the geometry and dynamic parameters have been made compared to the outgoing CRF450R, all of which give considerable benefits to both moto-cross and enduro riders. The centre of gravity height is 2.7mm lower. The wheelbase is 1482mm. Distance between the front wheel axle and swingarm pivot is 913mm, with distance from swingarm pivot to rear axle only 569mm. This geometry transfers more weight to the rear wheel for outstanding traction.
Seat height is 959mm. Rake and trail are set at 27.4°/116mm. Total wet weight is 118kg.
The CRF450RX is a slim, compact machine that’s easy to manage thanks to the low centre of gravity. Its rear tyre is loaded hard to dig for drive, matching the front end’s grip level and feel for traction at the limit.