OK – we know dirt bikes aren’t made for flat-out speed. They’re tuned, geared, and set up to perform in conditions that a built-for-speed sports bike simply couldn’t handle.
Nevertheless, dirt bikes have speedometers – and we are only human! Inevitably, the question – “which one is the fastest” arises.
We thought it’d be fun to look at some of the faster dirt bikes on the market today.
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Fastest Dirt Bike Options
KTM 450 SX-F
- Top Speed: 123mph
- Engine: 450cc four-stroke single
- Power: 63 HP
- Wet Weight: Approx 236 lbs
There are few dirt bikes with the straight-from-the-box performance seen in the SX-F. Easily one of the throatiest, most flickable machines on our list, this KTM has become the gold standard for contemporary dirt bikes.
Despite its modern performance, a rugged steel frame and beautiful-sounding single cylinder give this bike a classic look and feel. Like the rest of the KTM range, the SX-F transmitter can link to the My Ride app on your phone. This pairing can help you to get the most out of your new toy.
Clever new features include specially designed vent and engine covers. These stop your motocross boots, mud, and debris from entering or damaging the bike during vigorous romping in the muck.
Widely regarded as an out-of-box racing machine, the KTM 450 SX-F is one of the most potent bikes on our list. A smooth, even power delivery across the bike’s range and over various terrain makes this an easy pick for those after a top-end dirt bike.
Aprilia RXV 5.5
- Top Speed: 113mph
- Engine: 550cc four-stroke v-twin
- Power: 55hp
- Wet Weight: 268lbs
At first glance, the RXV sounds heavy for a dirt bike. This machine comes in at over 300 lbs with fuel and oil in the tank. But with its ultra-powerful, v-twin engine, slim frame, and engaged seating position, the RXV rides much lighter than its stats might suggest.
Part of the extra weight here may come from the cylinder arrangement. Most dirt bikes are set up as single cylinders. Here, the v-twin layout makes for a whopping 55hp and can go from 0-60mph in just over 4 seconds.
A flat-out speed of 113 mph should satisfy even the most inveterate thrill seekers. This bike never really took off in terms of sales. This is probably due to its unorthodox features for a dirt bike. Don’t let that put you off if you see one of these for sale on the secondhand market.
- Top Speed: 100mph
- Engine: 510cc single-cylinder four-stroke
- Power: 44.5hp
- Wet Weight: 252lbs
With a distinctly off-road appearance, you’d be forgiven for not realising that the FE501S is a street-legal dual sport. Most machines of this ilk lean more on road-specific aesthetics. The seating position, high-routed exhaust, and fairing setup here all look like something from a dedicated off-roader.
The mid to high-range power has always been on point with these machines. The 2020 redesign of the FE501S has added quite a bit of lower-end performance. This machine will pull you out of ruts, cracks, and muddy terrain just as well as carry you to the office.
The street-legal status of this one means it comes with mirrors, lights, and other accessories needed. None of these features takes away from the pure dirt bike aesthetic. If you’re after a powerful off-roader, you can ride on the street; this one is worth a look.
- Top Speed: 100mph
- Engine: 644cc, air-cooled, single cylinder
- Power: 40hp
- Wet Weight: 346lbs
With its rugged, retro design, the XR650L won’t be for everyone. But there’s no denying that every feature of the bike is a proven classic. From the big, single-cylinder, 644cc, air-cooled engine to the lightweight steel frame – everything on this street-legal machine is a result of thirty years of innovation and iteration from Honda.
They may produce bikes with more bells, whistles, and carbon fibre knick-knacks, but Honda rarely produces machines with this kind of utilitarian beauty nowadays. The black rims, heritage graphics, matte black exhaust, and gaiters all combine to give this a beautiful, vintage feel.
Honda’s advertising copy even lists this as “the ultimate post-apocalyptic commuter.” This suggests they know just how cool this dual sport machine looks – and how many people will want it as a daily machine. That’s not to say this won’t perform in the muck too. It’s just that it’s so pretty, it’d be a shame to get it splattered.
Space for a pillion passenger and passenger footpegs add even more functionality to an already impressive bike. If you’re obsessed with having all the latest tech, this won’t be for you. If you want a reliable workhorse built on tried-and-tested principles, the XR650L is well worth a look.
Kawasaki KLR 650
- Top Speed: 90mph
- Engine: Liquid-cooled, transverse single cylinder
- Power: 36.4hp
- Wet Weight: 487lbs
Kawasaki’s KLR is a modern interpretation of a classic bike with a pedigree stretching back to the 1980s. This means it has a reasonably low-tech, analogue feel. But it also means that every component and feature here has been honed and iterated for decades.
The result is a dual sport machine that’s fun on the street, adept at taking on dirt tracks, and has a respectable top speed of 90mph. Oh, and it looks pretty cool too. One figure on the specs list that may cause some concern is the weight. At 487 lbs with fuel and oil in the tanks, the KLR is no lightweight.
Thankfully, the smooth, powerful engine and reliable suspension mean this extra weight never contributes to a feeling of sluggishness.
The stiff, mechanical throttle will feel jarring to those used to assistance from the latest hot wire technology. But for those who like their bikes with some old-school character, the KLR makes a lot of sense.
Servicing at home is also a real possibility here. The older design principles mean many riders will already be familiar with the inside of this bike.
Kawasaki KX 450
- Top Speed: 90mph
- Engine: 499cc liquid-cooled single
- Power: 53hp
- Wet Weight: 246lbs
The KX 450 will be no stranger to motocross fans. It uses the wisdom of Kawasaki’s forty-year KX-model heritage and the latest rider aids to deliver a thrilling, state-of-the-art ride. And it’s one with many podium-winning performances to its name.
One of the first things to notice about the KX is its lean chassis. This is a pure racing machine designed for limited drag and maximum overtaking possibilities. This is the purest, dirtiest dirt bike of all the machines on this list.
The 2023 model adds new Uni-trak suspension with adjustable high/low-speed compression damping and adjustable preload. The KX models have always been known for their excellent suspension. These later revisions make it even better.
Cornering feels quick and responsive. The Renthal flat bars and seating position work together to create agile handling. But this probably does come at some cost to the bike’s feeling of stability at high speed. This is a standard tradeoff when it comes to motocross bikes.
Honda CRF 450
- Top Speed: 87mph
- Engine: 499cc four-stroke single
- Power: 45hp
- Wet Weight: 260lbs
The CRF 450R is a machine that Honda has iterated upon for many years. It’s a legendary bike in motocross. And with its overhaul in 2017, it has become a solid, contemporary performer. It will also do 87mph flat out – pretty respectable for a 450cc dirt bike.
The latest model of the 450R places the battery box lower. This brings the centre of gravity closer to the ground and improves balance and handling. Honda’s Selectable Torque Control allows riders to dial in the bike’s performance to suit the conditions.
Since 2019, the bike has also featured an upgraded exhaust, a new clutch lifter, and HRC launch control. This bike offers Honda build quality, reliability, and performance. It mightn’t go as fast as others on our list. But it’ll certainly go for a very long time – one of the best 450s on the market.