Most off-road motorcycle fans are familiar with the Honda CRF450 dirt bikes. The R and X variants have been very successful in motocross and endurance racing respectively. For 2017, they’re getting majorly revised for the first time in ages. And getting a brand-new sibling as well.

Honda’s tagline for the new-for-2017 CRF lineup is “Absolute Holeshot.”

For those unfamiliar with the motocross scene, the “holeshot” is basically referring to the fact that you have to haul absolute ass in the first 100 feet of an enclosed-course dirt bike race because a big bunch of bikes are all charging through a bottleneck to the same hole.

Hence, Honda’s sales pitch describing their engine as: “developed to achieve overwhelming performance in the first 100 feet of battle.”

The 2017 CRF450 will come in three variants– R, X and RX, each of which the company claims is ground-up new according to a .

The CRF450R, built primarily for motocross racing, runs a new “Unicam” engine with a “ultra-direct downdraft air intake, steeper valve angle and twin exhaust system with smoother routing.” These features are supposed to boost power across the rev range, but the fuel injection system is built around hard-charging from a stop to the first turn on an MX track.

The Unicam is advertised as having “the performance of a double-overhead-cam layout but the compactness of a single-overhead-cam design,” thanks in part to what Honda calls an “in-finger rocker design.” Basically, it’s layering the components that go above the piston together so they take up less space. Compression ratio is up to 13.5:1.

New chassis geometry is designed to concentrate and lower the bike’s center of gravity for stability. Shocks are a new coil-spring 49mm Showa fork up front with a swingarm that’s apparently “lighter and lower” than the previous R’s. A titanium fuel tank is also new for this model year and front brakes are bigger as well; up to 260mm in diameter.

The exhaust also moves weight toward the middle to improve balance.

These major changes are going to be applied across the lineup, with little tweaks for the “X” and “RX” variants.

The CRF450RX, a new designation altogether, is designed around woods racing. Honda claims it has a “smoother ignition map,” “off-road-focused suspension settings, a revised cylinder-head hanger and changed wheel hubs and axles.”

The RX will also run “off-road-appropriate components like a larger plastic fuel tank and a forged-aluminum side stand.” The term “off-road” here is referring to backcountry “outdoor” riding, as opposed to a motocross track.

Finally, the CRF450X is optimized for long-haul endurance races like the Baja 1000. Honda has vaguely listed “a trail-tuned chassis and superior ergonomics” in its , but it seems like the X’s primary differentiator is the use of a Honda Progressive Steering Damper, “which aids cornering and helps to reduce arm fatigue.”

I’ve been hearing good things about Honda’s CRF lineup since I crewed my first off-road race in 2011. It will be interesting to see how racers, and the competition, respond to the 2017 tweaks.