EMBRACE WINNING, ON OUR BEST ENDURO EVER
THE REDESIGNED 2021 CRF450RX
LIGHTER, NARROWER FRAME
Great handling starts with a superior frame, and we’ve made some big changes to our 2021 CRF450RX’s chassis. First, it’s lighter—over a pound and a half lighter. By making the frame’s main spars narrower, we saved weight, but more important we made the chassis more responsive by reducing lateral rigidity 20 percent. The result is a bike that gets into, around, and out of corners faster.
Designed in conjunction with the new frame, by using narrower main members (just like the frame uses narrower main spars), we’ve matched the swingarm’s lateral rigidity to the rest of the chassis. What you get is a balanced, fully integrated approach to frame stiffness, letting you get around corners faster and with better feel.
We totally redesigned the rear subframe to make it nearly three-quarters of a pound lighter, and along the way simplified its construction too.
NEW BATTERY BOX
Three key features changed here: The battery box is lower, for an improved center of gravity. Second, it’s also easier to service. And third, it’s now water-tight, so there’s nothing to worry about when racing in wet conditions.
We’ve increased the front suspension’s stroke by 5mm for 2021, for better handling and rider comfort. Also, we redesigned the axle holding fixtures at the bottom of each fork leg—that increases rigidity, and enhances steering precision and suspension performance. Finally, we retuned the suspension settings for a more compliant ride.
NEW TRIPLE CLAMPS
The CRF450RX is a perfectly matched package. With the frame and swingarm featuring a retuned lateral stiffness, and the fork legs featuring a new, stiffer axle fixture, we joined the two with new upper and lower triple clamps. Working in concert, they help improve and balance total rigidity, responsiveness and turning performance.
The 2021 CRF450RX’s new frame design gave us the opportunity to fit a new rear shock. We’ve optimized its shape to match the frame, and gave it new settings to work with the new chassis. The shocks valving resets faster for better response. In addition, we’ve fit a new steel spring that’s way lighter, cutting weight without cutting performance. And naturally, the RX gets its own shock settings optimized for enduro riding.
SHOWA® SPRING FORK
The 49mm Showa® fork is specially tuned just for the CRF450RX, and features a conventional spring design that helps increase the CRF450RX’s front-suspension precision, handling and feel.
The CRF450RX’s swingarm uses a special fabrication technique that lets us fine-tune the flex to work with the chassis and give you better rear traction and cornering precision.
NEW EXHAUST PIPE
Along with the single-muffler exhaust, naturally we gave the 2021 CRF450RX a new single-pipe header. We’ve completely changed the routing too, bringing it 74mm closer to the center of the bike. It’s lighter, and helps improve weight distribution.
NEW SINGLE-MUFFLER EXHAUST
Changing the muffler’s construction to a pressed-alloy design let us reshape it too, for better rider ergonomics and lighter weight. How much lighter? More than two and a half pounds!
NEW HYDRAULIC CLUTCH
This is huge news for the 2021 CRF450RX. Out with the old cable-actuated clutch, and in with the first hydraulically actuated clutch we’ve offered outside of our works bikes. Made by Nissin, it’s the same design as in our Grand Prix MX machines, and performs better than third-party conversions. You get a clutch-lever pull that’s ten percent lighter at its peak, even though it’s paired with a stronger clutch. Plus, you’ll never have to worry about making a clutch-cable adjustment, even during the longest events.
NEW CLUTCH ASSEMBLY
While the new hydraulic clutch is getting all the attention, we’ve made even more improvement with the parts that do the work: the clutch assembly itself. Say good-bye to clutch fade—we’ve upped the number of clutch plates from seven to eight, to improve durability and hookup. That means 85 percent less slip at peak horsepower, and 27 percent more total torque transmission through the clutch pack. Even the spring is stronger, but thanks to the hydraulic actuation, clutch-lever pull is lighter than ever.
Honda SELECTABLE TORQUE CONTROL (HSTC)
Changing terrain requires changing power character. No worries: The CRF450RX features our Honda Selectable Torque Control (HSTC). You can choose from one of three settings to perfectly dial your bike in depending on how much traction is available.
260mm FRONT BRAKE
The CRF450RX’s large front-brake disc measures a whopping 260mm. You get great brake feel and a pattern that cuts down on weight. Front and rear brake-disc guards are part of the package too.
ENGINE MODE SELECT BUTTON
This simple handlebar-mounted button lets you dial in engine power delivery character with a push of your thumb. Choose between Standard, Smooth and Aggressive, depending on track conditions.
NEW RESIN FUEL TANK
We fine-tuned the fuel tank and radiator shrouds to make the 2021 CRF450RX narrower up front so it’s easier for you to move on the bike. The 2.1-gallon capacity will let many riders complete a three-hour enduro with just one fuel stop.
COMPACT FUEL PUMP
No detail is too small for our engineers—especially if they can make it smaller and lighter. That’s what they did to the 2021 CRF450RX’s fuel pump. Why carry around any extra weight when you don’t have too? While they were at it, they reduced the number of attaching fasteners from six to four.
NEW RADIATOR SHROUDS
Using computer-aided Computational Fluid Dynamics, we’ve fine-tuned the CRF450RX’s radiator shrouds to increase cooling. They’re now a one-piece design, but more important, better cooling equals more consistent power, longer into a race, especially when you’re really on the gas and working the engine hard.
HRC LAUNCH CONTROL
We’re talking about a special ECU program here: push the button to select the mode, hold the throttle open, release the clutch, and the CRF450RX will do the rest, launching you into the first turn with a big advantage. It turns your bike into a holeshot-seeking machine!
LIGHT OVERALL WEIGHT
On an enduro racer, less weight is always better. That’s why our engineers are such fanatics when it comes to trimming grams from the CRF450X. You’ll feel the benefits everywhere: in acceleration, in suspension action, and most of all at the end of the day.
REAR BRAKE PADS
Brakes are for more than just stopping: they help you set up the bike in turns and jumps. Which is why we pay so much attention to detail like brake pads. They’re designed to last longer and give you even more stopping power—a real win/win to help you win.
NEW AIRBOX AND FILTER
Along with the new air filter, the airbox shape helps deliver more torque. You can access the airbox through the left number plate. And because the new filter has no rubber gasket where it interfaces with the intake boot, cleaning and servicing the filter is faster and less messy than ever.
Kickstarting? Maybe if you’re riding in the vintage class, but not here. By ditching the kickstarter entirely, our engineers can make the CRF450RX lighter. Electric starters and lithium-ion batteries are so light now and so good that putting them on a bike like this is a win/win combination. And winning is what a CRF450RX is all about.
NEW SWITCH ASSEMBLY
Check out the controls on the new 2021 CRF450RX. We’ve made them lighter, and more intuitive. Controls used to be your bike’s shifter, clutch, and brakes. Now you have things like launch assist, selectable power modes, and more. We believe they should be easy to use, and we’ve just made them easier.
DUNLOP GEOMAX AT81 TIRES
The CRF450RX’s Dunlop Geomax tires are specially designed for enduro use. The AT81 tires are spec’d at 90/90-21 for the front and 120/90-18 for the rear. You read that right: the CRF450RX rolls on an 18-inch rear wheel.
449cc UNICAM® ENGINE
Honda’s Unicam® cylinder heads combine the best of single- and double-overhead-cam designs. The configuration contributes to a compact engine that saves weight over a comparable dual-overhead-camshaft motor and also permits a narrow included valve angle. This flattens the combustion chamber to facilitate ignition flame propagation, allowing a high compression ratio. Since less space is taken up in the cylinder head, the camshaft sits lower in the head for a more compact engine and a lower center of gravity.
REVISED DECOMPRESSION SYSTEM
You can’t see this unless you take the engine apart, but you’ll notice it on the track. Our engineers redesigned the auto decompression hardware, and also moved it from the right side of the cam to the left. The result is less stalling at extreme low RPM (think deep into a turn without downshifting) as well as better rideability.
NEW CYLINDER HEAD
The 2021 CRF450RX gets a whole new cylinder head this year. Its biggest feature: an oval-shaped centralized exhaust port. Together with the new single-muffler exhaust, it boosts power from 5000 rpm up, and increases exhaust efficiency.
DOWNDRAFT FUEL INJECTION
The CRF450RX features a downdraft intake tract and FI body to help increase both power and fuel-metering precision. It’s part of the reason the CRF450RX offers such explosive power and massive torque, especially out of the starting line and in the critical first 100 feet of the race to the first turn.
TITANIUM INTAKE VALVES
Lightweight titanium intake valves cut down on reciprocating mass and permit the use of smaller valve springs, reducing overall engine height.
NEW FUEL INJECTOR BODY POSITION
We’ve changed the angle where the fuel-injector fits into the CRF450RX’s intake tract. By steepening the angle from 30 to 60 degrees, the injector now sprays fuel all the way back to the throttle butterfly. The engine gets a cooler, denser fuel charge for more power and better torque. It’s little details like this that put the CRF450RX up front.
DOUBLE-SPRAY INJECTOR SETTINGS
The CRF450RX’s fuel-injection system sprays twice per intake cycle. That helps increase fuel atomization without adding the weight or complexity of a second injector. The better fuel atomization means more power in the midrange and on overrev—you’ll feel it the first time you race.
13.5:1 COMPRESSION RATIO
Honda engineering at its best: The CRF450RX’s cylinder head features a highly refined combustion-chamber shape and generous squish area, allowing an impressive 13.5:1 compression ratio for superior efficiency and power.
CYLINDER HEAD LAYOUT
The CRF450RX uses our latest finger-follower rocker design. The Unicam cylinder head remains one of the most efficient in the off-road world, giving you the design and performance of a double-overhead-cam layout but the compactness of a single-overhead-cam design.
A factory skid plate is light and offers the engine and lower-frame protection that a racer demands.
NEW, SLIM BODYWORK
We’ve slimmed down the CRF450RX’s bodywork, and reduced the total number of pieces. It makes it a lot easier to move around on the new bike, and that maximizes your riding freedom. While we were at it, we reduced the total number of fasteners needed to remove the body panels—maintenance off the bike just got easier too.
You asked; we delivered. The new 2021 CRF450RX comes with handguards installed right from the factory. They’re fully integrated, too, not like some aftermarket add-ons. They attach right to the control-lever pivots, are color-matched to your new bike, and are even vented.
The aluminum Renthal Fatbar features a bend that’s even better than the legendary Honda “CR” bar. It’s the new standard of excellence—you’re gonna love it!
Sometimes you need to think out of the box—that’s what we did with the new CRF450RX’s seat. We moved the attaching bolts from the rear to the front, and the tongue from the front to the rear. The result? When it’s time for service, removing and installing your new CRF450RX’s seat is easier than ever.
FLAT SEAT/TANK JUNCTION
The CRF450RX features a flat seat/tank junction, including a titanium fuel tank. The superior ergonomics make it easier to move forward and back on the bike, increasing your control.
BLACK DID RIMS
They may not help you go faster, but the black DID DirtStar rims sure look good.
Real enduro bikes need a sidestand, and we’ve given the CRF450RX a great one. Plus, for 2021 we’ve made it even better. Since now there’s no muffler on the left side, we could tuck the sidestand in closer when it’s folded for better clearance. Nice.
FRESH NEW STYLING
A bike the works as well as the 2021 CRF450R should look just as good, right? That’s why we freshened up the overall graphics package. Plus, our “in mold” graphics help keep your bike looking good. We think the only thing that could make it look better is a big ol’ First Place trophy sitting on the seat. We did our part—the trophy is up to you.
NEW CABLE ROUTING
You may not notice it at first, but re-routing the CRF450RX’s throttle cables and new hydraulic clutch line let our engineers shave almost half a pound off the bike. Light is always right!