Honda has given the 2027 CRF450RX its most extensive overhaul ever, with a new engine, new frame, new suspension internals, new bodywork, and a long list of detail changes throughout. While the 2027 Honda CRF450R motocrosser shares most of the same updates, the two motorcycles diverge in meaningful ways. The RX continues to be tuned specifically for cross-country racing over rocks, roots, and rough terrain, rather than a groomed track. SLR Honda, Phoenix Racing Honda, and JCR Honda provided input into the development of the new RX. So, let’s dive in with the Fast Facts:
The new engine powering the 2027 Honda CRF450RX is 17mm narrower and six pounds lighter than the unit it replaces. Honda engineers got there by downsizing components wherever possible, changing the crankshaft profile from an anchor shape to a round one for increased rigidity, and switching the journal bearings on both sides of the crank from ball-and-roller to roller-only. The result, according to Honda, is a more efficient conversion of combustion pressure into rotational force, with less friction at the bearings and gear-engagement points.
The bore has been widened by 1mm, to 97.0mm, while the stroke has been shortened 1.3mm to 60.8mm, keeping displacement at 449.5cc. The larger bore, combined with revised piston-crown and combustion-chamber geometry, raises the compression ratio to 13.8:1 from 13.5:1. A DLC (diamond-like carbon) coating on the top piston ring reduces friction and improves durability.
Both intake and exhaust valves are now larger. Intake diameter increases 2mm to 40mm, while the exhaust grows 1mm to 32mm. The exhaust valves are now titanium instead of steel. That allowed Honda engineers to run a more aggressive cam profile. The new cam timing recovers the low-rpm output that larger valves would otherwise lose, while also making the valvetrain lighter and stronger. The angle between intake and exhaust valves has been optimized, and the rocker-arm shafts in the evolved Unicam system are now coaxial, making the mechanism more compact and rigid.
The intake port is steeper and shorter to enhance the RX’s downdraft intake advantage. A new airbox eliminates the lid of the previous design, routes air more directly to the filter, and uses a filter with revised density and a rounded design, replacing the slab-style filter. Combined, these changes reduce airflow resistance by approximately 10 percent.
The exhaust system was redesigned for the new engine and to meet tighter sound output limits. The header is 3.4 inches longer, and the aluminum muffler is 3.0 inches longer. It’s a dual-resonator design, with one resonator in the header and one in the muffler to manage noise while optimizing power delivery.
The clutch is an entirely new design, and impressively innovative. The basket diameter shrinks 7mm to 132mm, and the primary driven gear uses a lighter ring-type layout. The key change is a rubber-damper-activated back-torque limiter, an off-road-friendly alternative to the cam-type slipper clutch used on most high-performance street bikes. This new Honda system uses a rubber damper that deforms under back torque to reduce clutch capacity, smoothing corner-entry transitions. Honda tested the system extensively in MXGP competition. The hydraulically actuated 8-plate clutch retains good durability and a light lever pull.
All five gears in the transmission now have taller ratios. First changes from 18.954 to 18.173; fifth from 9.271 to 8.889. Honda says the revised ratios allow the engine to operate over a wider speed range in each gear, reducing the number of shifts. The shift drum is 13mm shorter and made of higher-strength material with thinner walls, cutting its weight by 46 percent. The entire transmission is 1.1 pounds lighter than before, a 15 percent reduction.
The starter system has been redesigned from the ground up, dropping more than a pound and improving reliability. The gear layout was reduced from five axes to four. The torque eliminator changed from a press-fit type to a friction-disc type using three disc springs and one friction disc, and the one-way starter clutch was downsized.
The electronic control package has been updated with input from racing teams. The 2027 Honda CRF450RX’s ECU uses dedicated fuel-injection maps to deliver a smooth, broad spread of power suited to technical off-road conditions. Three power modes — Standard, Smooth, and Aggressive — are selectable via a left-handlebar-mounted switch, with separate maps for first/second gear, third/fourth gear, and fifth gear, enabled by a gear-position sensor. There are three levels of traction control intervention, achieved by monitoring rpm spikes and responding by retarding ignition timing and adjusting fuel injection to control rear-wheel spin. If you like, you can switch traction control off. Launch control has three modes for your holeshot pleasure.
The main frame has approximately 70 percent new components, with longitudinal and torsional rigidity increased by about 10 percent and no increase in weight. The head-pipe area was reworked with a larger gusset that is now cast. The cylinder-head hanger plates are now aluminum instead of steel, saving a combined 0.3 pounds. The lower cradle and middle engine hanger were revised to accept the new, narrower engine.
Geometry changes follow the same logic as the CRF450R updates, though with subtle changes for more forgiving off-road optimization. The rear axle moves up 0.5 inches, and the CRF450RX’s wheelbase is 58.7 inches. Rake is 27.7 degrees, two-tenths more than the R. Trail on the RX is 4.7 inches, a tenth of an inch more than the R. The additional rake and trail give the RX a more planted, stable feel when navigating uneven terrain at speed. Also, the footpegs move rearward by 0.2 inches.
The swingarm is new, and the entire unit is hand-polished. The arms are larger in diameter with thinner walls, reducing weight by 0.9 pounds while maintaining rigidity. The main arm cross-section is now D-shaped with no sharp edges, minimizing drag in ruts and impacts with obstacles. The chain guide uses an impact-resistant resin developed by the Monster Energy Honda HRC Rally team. The chain slider has been reinforced top and bottom, with a small damping hole added to reduce chain bounce.
The Showa fork replaces the Bending Control Valve with a Dynamic Blow System main-piston-valve assembly. The 49mm inverted Showa fork also gets a stiffer spring, Kashima coating on internal sliding parts, a smaller hole in the main piston rod to increase low-speed damping force, a new aluminum cylindrical spring seat, and thinner, more numerous sub-compression valve shims. Critically, the fork settings on the 2027 Honda CRF450RX are tuned specifically for off-road use, and not repurposed from the CRF450R. The RX’s fork setting prioritizes smooth compliance over rocks and roots, minimizing step-like sensations throughout the stroke. Travel is unchanged at 12.2 inches.
The shock on the 2027 Honda CRF450RX gets a significant internal makeover. There’s a more responsive round bladder and a dramatically stiffer compression-damping adjuster spring (87.4 N/mm versus the previous 7.85 N/mm). A thrust needle bearing replaces the previous thrust washer, reducing friction for better traction feedback. Also, the SS25 shock oil is lighter than the SS37 used in the CRF450R shock, matching the fork oil and providing a more compliant, consistent feel suited to off-road terrain. The linkage ratio has been revised specifically for the RX to reduce kickback under acceleration while improving comfort and stability on rough ground. Rear wheel travel has been shortened 0.1 inches this year to 12 inches even.
The rear hub and sprocket are new. The units were designed using feedback from works-level racing programs to increase strength and serviceability while cutting weight by 0.6 pounds. The rear sprocket is a fully machined RK unit with a new mounting pattern that is 7mm larger than previous RXs.
The 2027 Honda CRF450RX gets a 1.9-gallon titanium fuel tank, shared with the new R. That’s down 0.2 gallons from the resin tank on last year’s bike. Honda says the smaller tank allows for a slimmer cross-section.
New bodywork matches the look of the Honda HRC Petronas MXGP team, featuring a red/white/blue tricolor scheme. The radiator shrouds and side panels are reshaped to deliver a flatter side surface that’s easier for the legs to grip. The seat has increased padding for comfort on long races. For those concerned about such initiatives, the front fender, front number plate, radiator shrouds, and seat base are made from post-industrial recycled materials as part of Honda’s Triple Action to Zero sustainability program.
All these changes mean the 2027 CRF450RX weighs 240 pounds, a staggering 16 pounds lighter than last year. Seat height is 37.4 inches, and the ground clearance is 12.8 inches, both 0.3 inches lower than last year.
Dunlop Geomax AT81 tires return. The front is a 90/90-21, slightly taller in section than the 80/100-21 on the CRF450R. The rear is a 120/90-18.
The 2027 Honda CRF450RX retains the accouterments expected by off-road riders. It includes plastic handguards, a full-coverage skid plate, and a kickstand, none of which show up on the CRF450R.
Extensive maintenance changes simplify routine service. The shock can be removed without pulling the ECU. The air filter is accessible through the side panel, and there is no airbox lid. The mounts for the rear disc and chain guide no longer use external nuts, so each can be installed with one wrench. The rear wheel’s side collars are rounded for easier installation and removal, so the wheel is more securely retained. The clutch hose routing is updated so the fuel tank can remain in place during hose replacement.
The 2027 Honda CRF450RX’s price pokes above $10k for the first time. It’s hard to complain when you’re getting a completely updated motorcycle that sheds 16 pounds. We can’t wait to sling a leg over this one.
2027 Suzuki GSX-R1000R + BTR Build Off Winner + Brian Bentley and the Ducati 916
byMotos and Friends by Ultimate Motorcycle
Hello and welcome again to the Motos and Friends Podcast. This episode is brought to you by Leod Escapes. My name is Arthur Coldwells.
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Have you ever wanted to ride a real MotoGP track? Well, here’s your chance! Leod Escapes does all sorts of amazing European tours, including the incredible Munich to Mugello tour at the end of June, or you can try the Core of Catalunya or the Portimão Andalusia trips, both in October. These are incredible touring experiences with the very best that Europe has to offer, as well as riding these amazing tracks on brand new BMW S1000RRs. So for the trip of a lifetime, visit LeodEscapes.com, now!
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In our first segment, Nic de Sena tells us all about his recent trip to Spain to ride the new 2027 Suzuki GSX-R1000R. Suzuki did a slightly different spin on this particular launch where they split the journalists into teams of 3, and had a 6-hour endurance ‘race’ to see how well everyone fared. Nic gives us the lowdown on what it’s like to the new Gixxer and for such long track sessions!
Rider Market from just outside Orlando, Florida, is the winner of the recent Royal Enfield BTR Build-Off competition in the Road Race category. Brian Koster is the Parts Director at Rider Market and he tells us briefly about the machine and parts he selected that made this retro-looking Royal Enfield stand out and take the trophy.
Our guest for this episode is Brian Bentley. A few years ago, just prior to Covid, Brian had a chance to buy a Ducati 916. He’s always been a major fan of the bike ever since it launched in the early nineties. He’d actually been looking for a 748 for a while, but when this great example came to his attention he couldn’t resist. The only snag was that it was completely disassembled. So, Brian did what any reasonable bike-fanatic would do: he loaded all the endless boxes of parts into the trunk of his SUV, headed home to Daytona Beach, and started the build. Brian recounts the story of this incredible machine and what eventually happened to it in the end.
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Here’s quick reminder to check out our monthly digital magazine. It’s filled with everything you want to read on motorcycling, including some things you’ve probably not seen elsewhere. It’s absolutely free and you will find it on the Apple App Store and of course on Google Play as well.
Don’t forget to leave us your comments on our social media—we’re on all the usual platforms at Ultimate Motorcycling. We love hearing your feedback… so good or bad, please let us know what you think. If there’s something you’d like us to cover, we’d love to hear those ideas too!
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