MXA RACE TEST: THE REAL TEST OF THE 2024 BETA 450RX

THE GEAR: Jersey: Alpinestars Supertech, Pants: Alpinestars Supertech, Helmet: Alpinestars M10, Goggles: Scott Prospect, Boots: Alpinestars Tech 10.

Q: FIRST AND FOREMOST, IS THE 2024 BETA 450RX BETTER THAN THE 2023 BETA 450RX?

A: Yes, because the 450RX is Beta’s first-ever 450 four-stroke motocross bike. The Italian brand has been around since 1905, and, remarkably, it has remained family owned the entire time. Beta made two-stroke motocross bikes in the ’70s and ’80s, but since then Beta has focused its attention mainly on trials bikes and off-road bikes. The 2021 Beta 300RX two-stroke was its first motocross-specific bike, and it was a precursor to this all-new 450.

Q: WHAT IS BETA ALL ABOUT?

A: Because it’s a small European brand, and probably because Beta uses steel frames, some people assume Beta is working with KTM in some capacity. We can assure you this isn’t the case. The Italian motorcycle manufacturer has been around much longer than KTM, with its inception dating back over 120 years. Originally under the name “Societa Giuseppe Bianchi,” Beta got its start making handmade bicycles and switched to motorcycles in the late 1940s. Beta is what is called a “boutique brand.” Betas are primarily bought through dealerships by pre-order, and the rider can actually customize the build through the BYOB (Build Your Own Beta) program when placing the order.

Beta is much smaller than the other major manufacturers, so the Italians have to be smart with their marketing. They don’t claim to have the fastest, strongest, lightest or most nimble bikes. Their tagline is “Rideability,” and their focus is on producing bikes that appeal to the common rider with a balanced chassis and a smooth engine. The Beta 450RX is an exciting new machine with a smooth power character.

Q: WHAT IS THE 2024 BETA 450RX BACKSTORY?

A: The 2024 Beta 450RX is the product of five years of development and four years of race testing in the MXGP series. In the World Championship, riders and teams are allowed to race on prototype machines, and there are no restrictions. For this reason, it can be exciting to see factory teams race on what may be next year’s models. Last year Romain Febvre raced the 2024 Kawasaki KX450, and  Tim Gajserwas racing the 2025 Honda CRF450.

Jeremy van Horebeek was the lead test rider/racer for the Beta factory team when they started racing MXGP in 2021, and Alessandro Lupino joined him for the 2022 season. For 2023 it was Lupino and Ben Watson, and for 2024, the team has Ben Watson and Ivo Monticelli representing Beta (Alessandro Lupino is now testing and racing for Ducati). Through race testing in the MXGP series, Beta was able to develop the 450RX that is now available to the public. This allows it to be homologated so it can be raced in AMA Supercross and motocross in 2024. Representing the factory Beta team are Colt Nichols and Benny Bloss.

The KYB forks were the most difficult part of the bike.

Q: WHAT IS THE 2024 BETA 450RX BASED ON?

A: Of course, this is a brand-new model for Beta. But, unlike the other two major incoming brands—Triumph and Ducati—Beta is already well accustomed to making dirt bikes. They have a full range of off-road-specific four-strokes in unique displacements that they currently race in the West Coast Off-Road Grand Prix series’ (WORCS and NGPC), desert races, East Coast GNCC races, EnduroCross and Hard Enduros. In the four-stroke range, Beta makes the 350RR, 390RR, 430RR and 480RR. In the two-stroke category, they make the 125RR, 200RR, 250RR and 300RR.

When developing the 2024 Beta 450RX, the Italians used their cross-country-ready off-roader as a starting point and, of course, they had to make a host of updates to dial it in for motocross.

Because Beta doesn’t currently have a 450cc engine for off-road, this engine is all new. The 450RX has a 5-speed transmission with separate oil compartments for the engine and transmission. It has a four-valve head, finger-followers, dual cams and uses electronic fuel injection with a 46mm throttle body. It uses a hydraulic Belleville washer spring clutch with a Brembo master cylinder and three tension settings on the spring to adjust the clutch feel. It also comes stock with a stainless steel HGS exhaust system.

As for the chassis, it uses a chromoly steel 450RX frame that is robot-welded and powder-coated red. This frame is new for this bike, and it was made stiffer for motocross with 10mm of added material around the steering stem. Compared to their off-road-specific frames, the steering stem angle is steeper for sharper cornering. The engine is rotated slightly back in the frame. Plus, the 450RX uses head stays that are specifically designed for motocross. This same frame comes on the “Race Edition” Beta RR off-road four-strokes for 2024, but it doesn’t come on the Enduro models. For suspension, the 450RX uses Kayaba, closed-cartridge, 48mm, AOS spring forks and a 50mm Kayaba rear shock. To stop, the 450RX relies on Nissin brakes. 

Once the suspension is fixed, the Beta 450RX is a blast to ride.

Q: HOW DOES THE 2024 BETA 450RX RUN ON THE TRACK?

A: The Beta 450RX engine is very tractor-like. It has a heavy feel that rolls on with a mellow power quality, reminding us of the new 2024 Kawasaki KX450, only it’s not quite as “free” or “quick-revving” as the KX. On a smooth track, our testers wanted more power and excitement, but when it got rough, they were thankful that the bike was easier to manage with its friendly power characteristics. 

The 450RX engine prefers to be ridden in the midrange and doesn’t want to be revved to the moon. Beta’s rev limiter is very unique, too. It has what engine tuners call a “slow” or “soft” limiter. It comes on at 11,100 rpm, which is in the same range as the 2024 KTM 450SXF, but the way it comes on is different. It gives off a flutter sensation at the limiter. Multiple test riders said that it feels like KTM’s Quickshift. Our test riders were confused at first, wondering if the bike had electrical issues, but once we realized it was normal, we got used to it. 

Although we are critical of some of its aspects, the 450RX engine isn’t bad, it’s just different. When you purchase the bike, it comes with an owner’s manual, a bracket to move the map switch from the middle of the handlebar pad to the handlebars, and four optional throttle cams that range from quick turn to slow turn. All our test riders preferred the quick-turn throttle cam because it gave the engine a more exciting low-end feel. 

Q: HOW DOES THE 2024 BETA 450RX RUN ON THE DYNO?

A: The Beta 450RX shined on the dyno. It came on strong with a dyno curve that was comparable to the 2024 KTM 450SXF curve. It matches the KTM for horsepower in the  6000 to 7000 rpm range, but the KTM does start to pull away at 8000 rpm, and it keeps pulling away into the 9000, 10,000, and 11,000 rpm ranges where the KTM peaks at 59.2 horsepower. The Beta 450RX peaks at 57.8 ponies. The torque curve, however, tells a different story. The KTM and Beta both hit a peak of 34.8 pound-feet of torque, but the KTM sustains it for much longer, while the Beta curve signs off sooner.

We also compared the two Beta 450RX maps on the dyno. The mellow map took the 450RX from 57.8 to 53.7 horsepower and the 34.8 pound-feet of torque to 32.8. It was significantly slower on the dyno and the track. Because the Beta 450RX is already a very gentle 450 four-stroke with a friendly power profile, we rarely elected to use the mellow map. Only one tester preferred it when riding in hard-packed and slick conditions. 

We now understand what Beta means by “Rideability.” :

Q: HOW DOES THE 2024 BETA 450RX HANDLE ON THE TRACK?

A: The Kayaba suspension hampers the Beta 450RX. The fork and shock do not agree with each other. The fork is stiff at the top of the stroke and soft at the bottom. It rides high in the stroke and can feel stiff until you grab the front brake or hit a big bump, then it blows through and gets very close to bottoming out. It’s a conundrum that had our test riders going around in circles at first. The shock is almost the opposite. It is plush and soft on top, but when you get into the midrange of the stroke, it gets stiff. We tried raising and lowering both the sag and the forks within the triple clamps. Ultimately, we decided to add 20cc of oil to the forks to help give some additional damping at the end of the stroke. Then we went out on the compression clicker to soften it up. Finally, we went out on the fork’s rebound adjuster to get some more movement in the bumps.

It comes stock with a Twin Air filter design, which copies KTM.

Engine braking affects how a bike slows down as it comes into corners, which affects the bike’s handling. The 450RX rolls freely off the throttle, with less engine braking in second and third gear. Of course, first gear brought out more engine braking, as you’d expect, but we rarely downshifted to first at corner entrance. The biggest effect of lots of engine braking is that it increases the load on the front end coming into corners. More weight on the front is a good thing because it steepens the head angle; however, it is not as pleasant when the forks are too stiff in the initial part of the stroke. Even though we said we rarely downshift when first approaching a corner, there were some tighter turns where we needed to go down a gear to increase front-tire traction and add some low-end grunt on corner exits.

The battery tray is arrayed neatly.

Thankfully, Beta has an in-house suspension team that can customize your suspension for your skill level and weight. They sent us a setting that helped significantly with the balance of the bike, giving our test riders much more confidence in the chassis. We expect them to fix the stock suspension settings for the 2025 Beta 450RX.

Q: WHAT’S UNIQUE ABOUT THE 2024 BETA 450RX?

A: This bike has a lot of interesting aspects to it that set it apart from the other brands. First, it has tool-less seat removal. You push a button to remove the seat, which is nice for washing the bike and protecting your seat foam. The seat is also very flat and hard. We recommend adding a seat bump under the cover to keep you centered on the bike and to help you feel like you’re sitting in the bike rather than on top of it. The tray under the seat is nice as well. A lightweight basket holds the battery, ECU and relays in one spot.

The Beta airbox is a copy of KTM’s tool-less air filter design. The plastic cover snaps on like an Austrian bike’s, and the stock Twin Air filter snaps into rubber grommets like the KTM filter—only it’s not as easy. It takes a little practice to get your fingers around it. The previously mentioned map switch/bar pad configuration is quite unique. Every test rider looked at it with trepidation, because the plastic-molded map switch stuck up above the bar pad and was dead center with where your chest would hit. Luckily, Beta does have an adapter to move the map switch to the handlebars. The front brake, clutch perches and master cylinders are all coated black, as is the swingarm, making the stock bike look factory. The dual-layer sprocket is a nice touch, with an aluminum core and steel teeth for durability. This is the only motocross bike that uses a translucent fuel tank. You don’t have to remove the gas cap to see how much gas is in the tank.

The overall layout of the Beta is unique as well. Although it has a lot of red, it can’t be confused with a Honda or GasGas. The bodywork is almost equally red and blue. The rims and the seat are blue, and the graphics are blue and red. The muffler is 100 percent exposed; however, we did lose a bolt out of the muffler guard when a test rider squeezed too hard on it. Only our shortest test rider mentioned that he could feel the heat coming from the muffler, but he said it wasn’t hot, just warm.

The footpegs weren’t sharp enough.

Q: WHAT DID WE HATE?

A: The hate list:

(1) Suspension. The biggest issue with this bike is the stock suspension.

(2) Rev limiter. This engine has a lot of pros, but the con is the rev limiter, since it is unlike any other modern four-stroke. 

(3) Footpegs. The pegs looked fancy at first, but they weren’t sharp and wore out quickly. 

(4) Seat. The seat layout could use more foam. It’s flat and hard. 

(5) Width. The fuel tank is on the wide side, bowing out more than other tanks. It feels like a 2022 or prior-model Yamaha YZ450F. It’s not terrible, but it takes a few laps to get used to it. 

(6) Maintenance. The dual-compartment transmission and engine oil situation adds a few extra steps to a routine oil change. 

(7) Fuel tank. We are 50/50 on the translucent tank. It makes the 450RX look like an off-road bike, but it’s very practical and nice for checking the fuel level at a glance.

(8) Weight. Without fuel, but all other fluids included, the 2024 Beta 450RX weighs 239 pounds, which is the same weight as the Suzuki RM-Z450 and Kawasaki KX450.

Q: WHAT DID WE LIKE?

A: The like list:

(1) Power. This engine is deceiving. It has a mellow power quality that is faster than it feels. 

(2) Aesthetics. Beta isn’t afraid to stand out, and we like that.

(3) Shock. The rear shock can be removed without lifting or removing the sub-frame. Remove the muffler, then remove the shock bolts (top and bottom) and the shock will pull out through the right side of the subframe.

(4) Map switch. It’s unique and kind of cool to have the map switch in the bar pad, but it is even nicer that it can easily be moved to the handlebars.

(5) Coatings. The black swingarm and brakes have a special thick paint on them. 

(6) No-tools filter. It’s nice to change a filter without having to open a toolbox. 

(7) Sprocket. The dual-material rear sprocket offers great value by adding durability.  

(8) Throttle cams. We’re glad they offer four extra throttle cams to adjust the power delivery. We preferred the black number 44 quick-turn cam. 

Q: WHAT DO WE REALLY THINK?

A: This bike is perfect for riders who like to stand out from the crowd. Since Beta is a smaller manufacturer and an all-new brand for motocross, odds are you’ll be one of the few riders on a Beta in your area. Owning the new Beta 450RX will mean that you need to get the suspension re-valved, but this bike does have potential. It reminds our more experienced test riders of the 2012 KTM 450SXF—a bike that wasn’t quite race-ready in stock form, but it had great potential once you got the suspension dialed in. 

Because it’s a smaller brand and an all-new model, there are fewer aftermarket parts available for the Beta 450RX; however, Beta has assured us that they are committed to the motocross market and aren’t going anywhere.