2021 Honda CRF450RX Review

[Admin]

In only its fifth year of existence, the Honda CRF450RX has received a complete overhaul. The entire chassis has been updated, including the frame, subframe, swingarm, suspension, triple clamps, and bodywork. The engine received major changes to the cylinder head, intake tract, and EFI; it also now has a single muffler exhaust system. The 2021 CRF450RX remains a serious off-road race machine with the same high-power engine and sharp handling characteristics as the CRF450R motocross bike.

Riding the 2021 Honda CRF450RX. (Jeff Allen/)

Since the CRF450RX is an off-road competition model, it does have a few added features that make it more race-ready for events such as hare & hound, Grand National Cross Country (GNCC), and open desert racing. Those include softer suspension valving and springs, dedicated ECU mapping, a larger 2.1-gallon fuel tank, 18-inch rear wheel, O-ring chain, skid plate, and sweet OEM hand guards.

In its fifth year on the market, the Honda CRF450RX is all-new. (Jeff Allen/)

2021 Honda CRF450RX Engine

Since this engine was introduced in 2017, it’s been unbelievably fast. The problem, if there is one, lies in controlling it. Honda took big steps to make it more rideable, with a new cylinder head featuring an oval-shaped center exhaust port along with the aforementioned single-muffler exhaust system. These changes actually allow for even more overall horsepower, but Honda worked on the EFI mapping to improve rideability.

Related: 2021 Honda CRF450RX Dyno Test

Since Honda introduced the CRF450RX in 2017, its engine has been an absolute fire-breather. It still is for MY21 but much more controllable. (Jeff Allen/)

Big Red also made some serious improvements to the clutch, not only increasing its surface area by adding another clutch plate, but also putting in an additional clutch spring. The real icing on the cake is the silky-smooth hydraulic clutch system. The transmission is the exact same five-speed that comes in the CRF450R, but Honda has geared down the final drive to 13/50, compared to 13/49 on the motocross model.

So Honda’s 2021 changes are noticeable, and more power combined with more manageability is without a doubt an improvement. Still, this is an engine for a rider who likes open-class power, knows how to use it, and most importantly, respects it.

One of our favorite updates is the clutch. It is now hydraulically actuated and has a silky-smooth pull. (Jeff Allen/)

2021 Honda CRF450RX Power Tunability

If you haven’t ridden a CRF450R, you would have a hard time believing the ECU mapping on the CRF450RX has been slightly toned down. There are three EFI settings: map 1 (standard), map 2 (smooth), and map 3 (aggressive). Add to this three levels of Honda’s Selectable Torque Control (HSTC) for each of those base EFI settings.

All these options can be toggled through with the buttons on the left side of the handlebar, allowing the CRF450RX to be easily tuned for many different conditions. Compare these impressive new electronics to those on any of the newer 450s; KTMs and Yamahas come stock with a dual map switch, while Kawasaki has an optional coupler that gives you three different settings.

A new level of on-the-fly adjustability. Three EFI maps and Honda Selectable Torque Control (HSTC) provide a ton of options for fine-tuning the engine’s power delivery. (Jeff Allen/)

KTM’s version of traction control has an on-or-off switch. Honda’s newest version of what it calls “Torque Control” has three levels of intervention, giving you the ability to really dial in the three EFI maps. My best description of Honda Selectable Torque Control is that it’s a bit like dragging the rear brake to keep the rear wheel from losing traction. On level 3, the highest level of intervention, I had to think much less about throttle control and was able to focus more on corner exit and getting the bike in line for the next obstacle. Note that when I say “think less,” I mean that, when really hard on the throttle, the engine simply seemed to understand that it shouldn’t allow the tire to spin. One thing you can be sure of is no matter what settings you select on the electronics suite, there will always be far more power than you need.

The 53.2 hp and 34.3 pound-feet of torque will get you through some snow if the terrain and temperature call for it. (Jeff Allen/)

2021 Honda CRF450RX Suspension

The CRF450RX’s Showa suspension has been given a few tweaks to make it a little more off-road friendly. The internal valving and spring rates are different from the moto version; the RX has 4.8 Nm fork springs (compared to 5.0 Nm on the R) and a 50 Nm shock spring (compared to 54 Nm on the R). Also, while the fork may look the same as the 2020 model’s, it’s actually 5mm longer to fit the all-new 2021 chassis.

Overall, the suspension is noticeably softer than the CRF450R’s, possibly even softer than the 2020 CRF450RX’s. For off-road, it seems to respond well and helps give the bike a more planted feeling; it’s fairly well balanced with a slightly high rear end sensation, but that’s more from the chassis and linkage.

A softer suspension setting than the motocross model gives the CRF450RX a more planted feeling. (Jeff Allen/)

2021 Honda CRF450RX Chassis/Handling

Staying in line with the motocross version, the CRF450RX was given the latest-generation chassis. It’s lighter, slimmer, and more stable, whereas “stable” is something the 2020 model was not. It’s especially noticeable when compared to a KTM cross-country model like the 450 XC-F.

Honda’s stated design goal of centralizing the bike’s weight under the rider makes this a chassis that’s very sensitive to rider input, though less so than the 2020 model. Big Red may have improved stability, but this is still a high-performance chassis that leans toward agile cornering and is very responsive to rider input. Like the engine, it can be unbelievable when used correctly, but it absolutely demands respect.

Although still very sensitive to rider input, the all-new chassis is much more predictable and forgiving. (Jeff Allen/)

The CRF450RX feels like its wheelbase is smaller, meaning minor shifts in body position have a big influence on how the bike reacts. For perspective, the opposite end of that spectrum would be a KTM, where the chassis and wheelbase feel longer and the bike is less affected by rider movement and position. The red machine’s 2.1-gallon fuel tank is also less of a hindrance than in years past, but it’s still noticeable. The rider triangle is still the classic Honda setup, and quite comfortable, though the bike does feel tall and somewhat stink bug.

How Does the 2021 Honda CRF450RX Ride?

This is a category of bike I love to ride. Here on the west coast of the United States, there is so much open land that a rider can really let a 450 stretch its legs. There are some tighter sections, but they’re still fairly open in comparison to enduro-type areas back east.

I spent a great deal of time on the previous-generation CRF450RX and, boy, was that a love-hate relationship. When things were going well, I could easily go faster on that bike than any other. When things went wrong, I was seeing my life flash before my eyes.

We like the slimmer bodywork as it makes it easier to move around on the bike while riding. (Jeff Allen/)

Honda did an excellent job of improving most of what I felt was needed. The bike has a more controllable engine and a far more forgiving chassis. It’s more predictable on faster trails and easier to handle on tighter trails, but most crucially, it’s more recoverable when you start to lose control. Front wheel predictability seems improved by 200 percent. I wouldn’t put it in the category of a KTM or Yamaha with regard to stability, but I feel much more comfortable letting the 2021 CRF450RX slide around under me.

If there was an award for the most improved bike of 2021, the CRF450RX would be the favorite. (Jeff Allen/)

In my book, the CRF450RX is still the highest-performance off-road competition 450 on the market. Like Honda’s two motocross bikes of the same displacement, the CRF450R and CRF450RWE, this cross-country racer falls into what I personally consider the Formula 1 category. The improvements to the 2021 CRF450RX are huge; it’s still 90 percent racebike and 10 percent trailbike, but it’s 100 percent more fun to ride in both of those categories. I’d go as far as saying that, if you’re on the fence between buying the CRF450R or the CRF450RX, you leave nothing on the table by choosing the RX. On any given motocross track, anyone up to an expert-level rider will turn the same lap times on the RX as they would on an R.

Gearbox

Helmet: Arai VX-Pro4

Goggle: EKS Brand EKS-S

Jacket: Thor MX Terrain

Jersey: Thor MX Pulse Racer

Gloves: Thor MX Rebound

Pants: Thor MX Pulse Racer

Boots: Sidi Crossfire 3 SRS

2021 Honda CRF450RX Specifications

MSRP:	$9,899
Engine:	SOHC, liquid-cooled single-cylinder
Displacement:	449cc
Bore x Stroke:	96.0 x 62.1mm
Compression Ratio:	13.5:1
Transmission/Final Drive:	5-speed/chain
Dirt Rider Measured Horsepower:	53.2 hp @ 9,400 rpm
Dirt Rider Measured Torque:	34.3 lb.-ft. @ 7,000 rpm
Fuel System:	EFI w/ 46mm throttle body
Clutch:	Wet, multiplate; hydraulic actuation
Frame:	Twin-spar aluminum
Front Suspension:	Showa 49mm coil-spring fork, compression damping and rebound damping adjustable; 12.2 in. travel
Rear Suspension:	Showa shock, spring preload, high-/low-speed compression damping, and rebound damping adjustable; 12.3 in. travel
Front Brake:	Nissin 2-piston caliper, 260mm disc
Rear Brake:	Nissin 1-piston caliper, 240mm disc
Tires, Front/Rear:	Dunlop Geomax AT81; 90/90-21 / 120/90-18
Rake/Trail:	27.1°/4.5 in.
Wheelbase:	58.3 in.
Ground Clearance:	13.2 in.
Dirt Rider Measured Seat Height:	38.0 in.
Fuel Capacity:	2.1 gal.
Dirt Rider Measured Wet Weight:	250 lb.
Availability:	Now
Contact:	powersports.honda.com

View the full article