What is the Largest Dirt Bike? The BIGGEST 4-stroke dirt bike

Dirt bikes are a lot of fun! They can be used for racing or just riding around in the dirt. There are many different dirt bikes, including motocross bikes, enduro bikes, and trail bikes. But what is the largest dirt bike? That is a question that many people ask. 

In the last 10 years, 450cc motorcycles have been the largest dirt bike and on a steady incline. The newest models are all four-stroke ‘progressions’ from 250cc two-stroke race bikes (and their smaller counterparts).

The four-stroke ‘progressions’ of a 250cc two-stroke race bike are like the 125’s in that they’re all compact, easy to handle, and rapid but have their unique qualities. The 450s take it up another notch by being equally nimble yet having more power than some ATVs.

It is said that Honda and Kawasaki had been making 500cc four-stroke motorcycles for a long time, but their popularity just wasn’t there. This all changed when the 4 strokes came around with its dominating engine power compared to 2 strokes models.

The largest dirt bikes, 450 MOTOCROSS BIKES

  • Suzuki RM-Z450…$8999
  • Kawasaki KX450…$9299
  • Honda CRF450…$9399
  • Yamaha YZ450F…$9399
  • KTM 450SXF…$9999
  • Husqvarna FC450…$10,099

Suzuki RM-Z450 Dimensions

The Suzuki RM-Z450 is 2175 mm in length, 835mm wide, and 1260 high with a wheelbase of 1480 millimeters.

By knowing the Suzuki RM-Z450’s dimensions, you can determine how much room is required for parking.

Dimensions                 in mm in cm in inches in feet

Length 2175 217.5 85.63 7.14

Width 835 83.5 32.87 2.74

Height 1260 126 49.61 4.13

Wheelbase                1480 148 58.27 4.86

Ground Clearance     330 33 12.99 1.08

Dimensions and Capacity

Length 2175 mm

Width 835 mm

Height 1260 mm

Fuel Capacity 6.3 L

Saddle Height 960 mm

Ground Clearance 330 mm

Wheelbase 1480 mm

Kerb Weight 112 kg

Tires and Brakes

Tyre Size Front :-80/100-21, Rear :- 110/90-19

Tyre Type Tubeless

Wheel Size Front :-533.4 mm,Rear :-482.6 mm

Wheels Type Spoke

Front Brake Disc

Rear Brake Disc


The new MSRP of $5,000 is a steal compared with competitors in its class. It offers better handling and cornering due to being adjustable at character adjustability that can be tailored for different engines individually – not just one setting like before.


No electric start. The Showa 49mm fork is a little less agile than other brands, but it’s compensated by having one of the best balance-free rear shocks on offer. 

The Headdress frame made from lightweight aluminum makes this bike feel quite heavy at first glance – until you realize how responsive and agile they are.

The 2021 Kawasaki Ninja ZX-10R has been released, and it comes with a whole new look. The most notable aspect of this model is its graphics, which appear similar to those found on some cars in Europe or Asia rather than North America, where they’re more commonly seen as American muscle bikes.

With its new graphics and an updated engine, this bike still feels like the 2019 version. But with a few adjustments, you can tune your ride to have more power when on dirt or change gears easier in city streets.

Engine, Transmission, and Performance

The 2021 RM-Z450 is powered by a liquid-cooled four-stroke engine that produces an impressive 54hp at 9,000 RPM and a peak torque of 45 Nm coming in between 3,000 – 5500 rpm tunable via MXTuner 2 app for even more modifications.

The powerplant can be tailored to suit your preferences thanks to digital tuning equipment like maps or custom fuel/ignition settings, so you’ll always have what riding style suits best.

The heavy engine of the bike makes it feel less nimble than its competition both in terms of 250-pound weight and hefty feel on track. Fortunately, this issue has been significantly alleviated thanks to an app that can tune down some characteristics for increased performance through adjustments made by users via their smartphones.

The engine maps were tweaked to produce a more powerful and responsive ride. Before playing with these settings, it ran on our in-house dyno, where we saw 50 horsepower at 8800 rpm and 33 pound-feet of torque from 7600 RPM below.

This bike is not a “fire-breather,” as test rider Allan Brown put it, but the torque output makes up for any lack in direct drive. It has been reported to be smooth, and the clutch fades minimal thanks to its five-speed transmission that operates nicely off of bottom end or high revs when needed most.


The 450 motocrosser is an excellent choice for having the most fun on their first bike. It has a rigid frame that makes it feel less comfortable when going around corners, but this also means that you can easily turn in tight spaces.

The RM-Z450’s Showa 49mm twin chambered coil-spring fork, and Balance Free Rear Cushion shock is largely unchanged since they debuted. The only update needed for this riding experience is its rear suspension, which will be updated with a new version that has been designed specifically by riders themselves.

Kawasaki KX450F Dimensions

The intimidating Kawasaki KX450F Dimensions are enough to make any rider feel like they’re in their element. The Dimension’s 2185 mm long, 830 wide, and 1275 tall with a wheelbase of 1485 meters. Not too bad for something that size.

The Kawasaki KX450F is a bike with reach and height. The size may be unusual for some, but it’s well suited to riders who want something on the larger side of sports bikes.

Dimensions             in mm in cm in inches in feet

Length 2185 218.5 86.02 7.17

Width 830 83 32.68 2.72

Height 1275 127.5 50.2 4.18

Wheelbase 1485 148.5 58.46 4.87

Ground Clearance  340 34 13.39 1.12

Dimensions and Capacity

Length 2185 mm

Width 820 mm

Height 1265 mm

Fuel Capacity 6.2 L

Saddle Height 955 mm

Ground Clearance 340 mm

Wheelbase 1485 mm

Kerb Weight 110.2 kg

Tyes and Brakes

Tyre Size Front :-80/100-21 Rear :-120/80-19

Tyre Type Tubeless

Wheel Size Front :-533.4 mm,Rear :-482.6 mm

Wheels Type Spoke

Front Brake Disc

Rear Brake Disc

Front Brake Diameter 270 mm

Rear Brake Diameter 250 mm

Radial Tyre Yes


 KX™ Motorcycles are the only ones to offer an all-terrain, XC riding mode, and dirt jump capabilities. Their motorcycles represent what it means for a bike: reliable transportation on any terrain or slope with enough power that will take you where no other ride can.


The KX™450 engine is designed to provide broad torque and strong power throughout the rev range. This race-ready machine will stay ahead of any other engine in its class from start to finish.


The highly adjustable suspension package ensures a steady and safe ride, with firm damping contributing to optimal traction. You’ll feel like a champion with the winning performance. 


The KX™450 motorcycle is a reliable, fast-performing machine that will inspire you to take on any challenge. This race-ready bike comes backed by decades of championship-proven experience and has outstanding starting or braking power features – whatever your preference may be.


Cutting-edge technology and design have created a lightweight, agile chassis perfect for drivers who want an advantage on their race track.

Honda CRF450



  • 58.3 inches

Rake (Caster Angle)

  • 27° 7.’


  • 4.5 inches

Seat Height

  • 38 inches

Ground Clearance

  • 13.2 inches

Fuel Capacity

  • 1.7 gallons

Curb Weight

  • 244 pounds

cassis suspension brakes 

Front Suspension

  • 49mm inverted Showa fork with rebound and compression damping adjustability; 12.2 inches of travel

Rear Suspension

  • Pro-Link Showa single shock with adjustable spring preload, rebound, and compression damping adjustability; 12.4 inches of travel

Front Brake

  • Single 260mm disc with twin-piston caliper

Rear Brake

  • Single 240mm disc

Front Tire

  • Dunlop MX33 80/100-21

Rear Tire

  • Dunlop MX33 120/80-19


The new CRF450R has a light and elegant frame that makes it one of the best handling bikes on dirt or street.

The bike is more responsive, getting into corners faster.

The narrow main spars save weight and make the chassis ultra-responsive by fine-tuning lateral rigidity – it’s a formula for success in this day of lightweight bikes without coward steel.

With a single swinging arm, the new bike is able to combine stiffness from both frames. By using broader main members like those on your typical Briko frame (as opposed to more narrow ones), it’s able to maintain balance while still getting an excellent level of control during turns without sacrificing any stability or comfortability.


The CRF450RWE Works Edition includes all of the standard features you’d expect but also gets a special hand-ported cylinder head, Hinson clutch basket, and cover. 

Twin Air filter, Throttle Jockey graphics & seat cover upgraded DID DirtStar LTX rims, an exhaust system including titanium header revalved suspension black triple clamps. 

Honda’s Unicam cylinder heads are an excellent choice for those who want to save weight and space. With this design, you can enjoy the benefits of a single-cam or double overhead cam without having any negative effects on compression ratio or efficiency.

Yamaha YZ450F

Frame type Aluminium twin tube 

  • Seat details – 
  • Wheelbase 1,481 mm (58.3 inches) 
  • Length 2,191 mm (86.3 inches) 
  • Width 827 mm (32.6 inches) 
  • Height 1,271 mm (50.0 inches) 
  • Seat Height 960 mm (37.8 inches) If adjustable, lowest setting. 
  • Alternate Seat Height – 
  • Ground Clearance 330 mm (13.0 inches) 
  • Trail size 116 mm (4.6 inches) 
  • Wheels details Dunlop MX3S tires 
  • Front Tyres – Rims dimensions 80/100-21 
  • Rear Tyres – Rims dimensions 120/80-19 
  • Front brakes Single disc. Hydraulic. Two-piston calipers. 
  • Rear brakes Single disc. Hydraulic. Single-piston caliper. 


Yamaha’s new YZ450F is a powerhouse on the track with an engine that will make you confident to push it further and try some outside lines. 

With incredible stability, this bike encouraged us all over 60MPH without feeling unstable at any point in time – perfect for anyone who wants more out of their adventures.


Yamaha’s YZ450F is an excellent choice for those who want to compete in motocross. The exhaust and airbox noise could both be improved with a little work, but it doesn’t take much effort or cost to get on track. 

You can make your ride more comfortable by replacing the clutch cable with something like a hydraulic unit that will allow you a taller seat.


The Yamaha YZ450F is a top-tier motorcycle taking second place at the annual Dirt Rider Shootout for years now. It’s widely considered because it offers powerful engines and predictable handling, as well as a comfortable suspension to match its ergonomic design – but there was just one little area where they fell short: their fuel efficiency.

Engine, Transmission, and Performance

The Yamaha YZ450F is a fast and powerful motorcycle that will blow you away with its performance. At 53hp, it can produce over twice as much power as other motorcycles in its class.

With an adjustable Power Tuner app for endless fuel delivery options or ignition timing tunability (depending on what type of rider you are), this bike guarantees to deliver all riders deserve from their ride today.

The tunability of the Power Tuner app, first introduced in 2018, offers a best-in-class tuning capability that we found useful when smoothing out the engine’s power delivery. 

We noted it affected lower rpm riding, where you might notice slightly more wheel spin than other 450cc motorcycles but not enough to be significant unless someone has really sensitive ears or can’t stand some noise coming from their bike.

The five-speed transmission is modulated with an easy pull cable that doesn’t fade. 


KYB has made the most comfortable and plush suspension in its class. It’s easily adjustable, working great even for various rider abilities or weights, with excellent base settings from just one adjustment setting after sag is set.

The KX450 offers a smooth ride with plenty of stability, but it falls short compared to other bikes in terms of flex.


KTM 450 SX-F Dimensions, Aerodynamics and weight

Frame type 25CrMo4 steel central-tube frame 

  • Seat details – 
  • Wheelbase 1,485 mm (58.5 inches) 
  • Length – 
  • Width – 
  • Height – 
  • Seat Height 960 mm (37.8 inches) If adjustable, lowest setting. 
  • Alternate Seat Height – 
  • Ground Clearance 370 mm (14.6 inches) 
  • Trail size – 
  • Wheels detail CNC machined hubs. Excel rims. Wire spoked. 
  • Front Tyres – Rims dimensions – 
  • Rear Tyres – Rims dimensions – 
  • Front brakes Single disc. Brake calipers on floating bearings 
  • Rear brakes Single disc. Brake calipers on floating bearings 
  • Front Brakes Dimensions – Disc Dimensions 260 mm (10.2 inches) 
  • Rear Brakes Dimensions – Disc Dimensions 220 mm (8.7 inches) 
  • Curb Weight (including fluids) – 
  • Dry Weight 100.2 kg (220.9 pounds) 
  • Front Percentage of Weight – 
  • Rear Percentage of Weight – 
  • Weight-Power Output Ratio : – 
  • Fuel Tank Capacity 7.00 litres (1.85 gallons) 
  • Reserve Fuel Capacity – 
  • Carrying Details and Capacity – 
  • Front Suspension WP-USD, AER 48, Ø 48 mm 
  • Front Suspension Travel 300 mm (11.8 inches) 
  • Rear Suspension WP shock absorber with linkage 
  • Rear Suspension Travel 300 mm (11.8 inches) 

2022 KTM 450 SX-F Engine

The 450 SX-F engine is one of the most reliable on the market, with an impressive number that can go without needing a rebuild. It might not have as much bark or torque compared to other engines, but it’s stronger than them all nonetheless.

How long will my clutch last? The answer is in the Brembo hydraulic system and KTM’s Belleville washer setup. This conjunction ensures that you won’t need to replace any plates for many miles down the road, if at all.

The five-speed gearbox has excellent spacing, which, combined with a smooth clutch action, makes shifting easy. Its minor weaknesses are the degree of engine braking and some noticeable vibration that can be felt during spirited driving or when new on your vehicle’s engine life cycle – but it will disappear after 20 hours worth.

2022 KTM 450 SX-F Suspension

When it comes to WP suspension, the first thing that you need is time. The components are slow in adjusting and will take some riding before they’re comfortable enough for your specific needs as a rider, so don’t get discouraged if, at first glance, these new updates seem too challenging.

The KTM is a great bike to ride, but it could be more balanced with stock settings. I recommend getting the suspension tuned by your local dealer or tuner before you hit any roads that are twisty-windy enough for this type of motorcycle and terrain where there might not always be someone around who knows what they’re doing.

2022 KTM 450 SX-F Chassis/Handling

Weighing in at just 235 pounds, the KTM 450 SX-F is easily one of the lightest and most balanced motocrossers on today’s market. It has been classified as such since it hit Dirt Rider scales five years ago with a weight that was less than many competing bikes from Honda or Yamaha.

The orange bike has a fairly neutral feel while cruising around the pits. It’s open and would comfortably fit riders measuring 6 feet or more; from the seat, it feels like you’re sitting on top of this machine rather than inside its chassis as with some other bikes that could make for an easier ride at high speeds because there is no obstruction between your legs when cornering hard.

Husqvarna FC450

2021 Husqvarna FC 450 Claimed Specifications

  • Engine: 450cc, SOHC, liquid-cooled, single-cylinder four-stroke
  • Bore x Stroke: 95.0 x 63.4mm
  • Transmission/Final Drive: 5-speed/chain
  • Fuel Delivery: Keihin electronic fuel injection w/ 44mm throttle body
  • Clutch: Wet, multi-plate, hydraulically actuated
  • Engine Management/Ignition: Keihin EMS
  • Frame: Steel central double cradle
  • Front Suspension: 48mm WP Xact fork, air pressure, compression damping, and rebound damping adjustable; 11.8 in. travel
  • Rear Suspension: WP Xact shock, spring preload, high-/low-speed compression damping, and rebound damping adjustable; 11.8 in. travel
  • Front Brake: Brembo 2-piston caliper, 260mm disc
  • Rear Brake: Brembo 1-piston caliper, 220mm disc
  • Wheels, Front/Rear: Spoked D.I.D; 21 x 1.60 in. / 19 x 2.15 in.
  • Tires, Front/Rear: 80/100-21 / 120/90-19
  • Rake/Trail: 26.1°/N/A
  • Wheelbase: 58.5 in.
  • Ground Clearance: 14.6 in.
  • Seat Height: 37.0 in.
  • Fuel Capacity: 1.9 gal.
  • Wet Weight: 223 lb. (w/o fuel)


This bike is so light that it has the second-lowest dry weight in its class. 

The strong, responsive Brembo brakes will bring your stopping power to a halt without any worries about being unable or unwilling to continue riding due to an accident.

With top-of-the-line components like these, you’re sure not going anywhere fast on this ride either – just look at how quickly those corners get carved up thanks to all that technology from Magura and ODI.


Though it has lightweight, the engine feels like it’s doing more than what you asked of it.

The response from your throttle isn’t as crisp and sharp compared to other bikes in this class which makes driving easier on those trying days when focusing just needs one hand.


The Husqvarna FC 450 is an all-new motocross bike in fourth place amongst other competitive models. This Austrian-made machine’s latest version participated in Dirt Rider’s 2021450 Motocross Bike Comparison, where test riders ranked it against the Yamaha YZ450F, Kawasaki KX450, and Honda CRF45R, among others. 

But due to its lack of low-end power and crisp throttle response with some heavier feeling engine character, they placed it near middle rankings overall, however–a respectable showing for such great equipment.

Engine, Transmission, and Performance

This 350 single-cylinder engine is liquid-cooled and has a central double-cradle frame. Our in-house dyno produced 55 horsepower at 9200 rpm while 34-pound feet of torque was found with 7400 RPMs, which puts it second only to its competitors for peak power.

Output: This 450cc SOHC model boasts an impressive top speed due to its lightweight aluminum alloy cylinder head, allowing quicker response time when you tap on the gas pedal.

When test riders analyzed the engine during their first ride, they stated that it has “the easiest to control the motor of all 450 motocross bikes.” Additionally, its smooth and linear power delivery makes for a friendly Dirt Bike that decreases fatigue in longer races. 

Both features are specifically for veteran racers who want an easy-going machine without unnecessary stress or hassle.

Jim Harmer

I am Jim Harmer and I am in love with the outdoors. I share all the information I know on all activities I like doing in my home in this website. You are welcome to read and reach out for more information.

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