KTM 105 SX Top Speed and Performance Specs

KTM 105 SX Top Speed and Performance Specs

Looking for a small but mighty off-road machine that can blaze through the trails? The KTM 105 SX might just be the perfect fit. This compact dirt bike packs a serious punch, delivering blistering speeds that defy its pint-sized stature. So, what is the top speed of the KTM 105 SX? And how does it stack up against its competitors? Let’s dive in and explore the performance prowess of this Austrian motocross marvel.

A Closer Look at the KTM 105 SX

Design and Features

The KTM 105 SX is a purpose-built motocross bike designed for young and beginner riders. Its compact dimensions and slim profile make it easy to maneuver, while the large 19-inch front and 16-inch rear wheels provide a confidence-inspiring riding stance.

One of the standout features of the 105 SX is its adjustable handlebar position. With four different settings, riders can tailor the ergonomics to their preference, ensuring a comfortable and controlled riding experience.

Under the sleek bodywork, you’ll find race-inspired components like a chromium-molybdenum frame, disc brakes, and high-performance suspension. It’s clear that KTM has packed this small package with big bike DNA.

The Need for Speed

Top Speed Unveiled

So, let’s get to the heart of the matter – the KTM 105 SX top speed. According to various sources and owner reports, this little ripper can reach a blistering top speed of around 55-60 mph (88-96 km/h).

To put that into perspective, most 110cc dirt bikes typically max out at 35-45 mph (56-72 km/h). The 105 SX’s higher top speed can be attributed to its larger displacement (105cc) and performance-oriented design.

Blistering Acceleration

But top speed is only part of the equation. The KTM 105 SX also impresses with its lightning-quick acceleration. Thanks to its potent power-to-weight ratio, this bike can rocket from 0 to 60 mph (0-96 km/h) in a matter of seconds (exact figures are unavailable).

Potent Power Plant

Powering this speed demon is a 103.96cc liquid-cooled, two-stroke, single-cylinder engine with a Keihin PWK 28 carburetor. While the power output figures are not officially disclosed, owners report that the engine delivers a healthy dose of torque and a wide, usable powerband.

Coupled with a six-speed transmission and a 14:49 final drive ratio, the 105 SX’s engine ensures that you’ll never be wanting for grunt, whether you’re blasting down a straightaway or powering out of tight corners.

Dissecting the Specifications

To better understand the performance capabilities of the KTM 105 SX, let’s take a closer look at its key specifications:

Engine103.96cc liquid-cooled two-stroke single
ConfigurationSingle-cylinder, two-stroke
Fuel SystemKeihin PWK 28 carburetor
Transmission6-speed manual
Final Drive14:49
Front Brake220mm disc
Rear Brake200mm disc
Front SuspensionWP USD Ø 43mm, 275mm travel
Rear SuspensionWP monoshock PDS, 300mm travel
Front Tire70/100-19″
Rear Tire90/100-16″
Wheelbase1290 ± 10mm (50.79 ± 0.39″)
Ground Clearance415mm (16.34″)
Dry Weight149.9 lbs (68 kg)
Fuel Capacity1.3 gallons (4.9 liters)

This impressive spec sheet highlights the 105 SX’s focus on performance, with features like large-diameter suspension, beefy brakes, and a lightweight chromium-molybdenum frame contributing to its speed and agility.

The Thrill of the Ride

Handling and Control

But speed is only part of the equation when it comes to an exhilarating riding experience. According to owner reviews, the KTM 105 SX delivers a controlled and responsive ride, with precise steering and excellent stability at higher speeds.

The bike’s nimble handling and flickable nature make it a joy to toss around tight trails and negotiate tricky terrain. And when it’s time to scrub off speed, the powerful disc brakes provide reliable stopping power with a progressive feel.

Comfort and Ergonomics

While the 105 SX is undoubtedly a performance-oriented machine, KTM hasn’t sacrificed comfort and ergonomics. The adjustable handlebar position allows riders to find their ideal riding stance, while the well-damped suspension soaks up bumps and keeps the tires planted over rough terrain.

Taller riders may find the compact dimensions a bit cramped, but for the bike’s intended audience of youth and beginner riders, the ergonomics hit the sweet spot.

What Determines Top Speed?

So, what factors contribute to the KTM 105 SX’s impressive top speed? As with any motorcycle, it’s a delicate balance of several elements:

  1. Engine Power: The 105 SX’s high-revving two-stroke engine delivers a impressive power-to-weight ratio, providing the necessary grunt to reach high speeds.
  2. Gearing: The bike’s close-ratio six-speed transmission and 14:49 final drive ratio are optimized for strong acceleration and high top-end speeds.
  3. Aerodynamics: While not a major factor for off-road bikes, the 105 SX’s compact dimensions and streamlined bodywork help reduce wind resistance at higher speeds.
  4. Weight: At just 149.9 lbs (68 kg) dry, the 105 SX is a relative featherweight, allowing its modest engine to propel it to thrilling speeds.

It’s worth noting that while top speed is an exciting metric, it’s not the be-all and end-all for off-road riding. Factors like low-end torque, suspension performance, and overall control are often more critical for conquering rugged terrain.

Owner Perspectives

Positive Owner Reviews

But don’t just take our word for it. Here’s what some satisfied KTM 105 SX owners have to say:

“The power-to-weight ratio on this bike is insane! It’s an absolute rocket ship off the line and can hit some seriously fast top speeds for its size.” – Jason T., California

“I was blown away by how well the 105 SX handles. It’s flickable and precise, yet still feels planted and stable even at higher speeds. An absolute blast to ride!” – Emily R., Colorado

Negative Owner Feedback

Of course, no bike is perfect, and the 105 SX has its fair share of criticisms from owners:

“The rear brake felt a bit too sensitive and grabby for my liking. I had to really modulate the pressure to avoid locking up the wheel.” – Mark P., Texas

“While the engine is a ripper, the vibrations can get a bit buzzy, especially during longer rides. Some extra vibration damping would be nice.” – Kyle W., Oregon

Competitor Comparison

So, how does the KTM 105 SX’s top speed stack up against its rivals? Here’s a quick comparison:

  • Honda CRF150R: Top speed around 55 mph (88 km/h)
  • Kawasaki KX100: Top speed around 50 mph (80 km/h)
  • Suzuki RM85L: Top speed around 45 mph (72 km/h)

As you can see, the 105 SX holds a clear advantage in the top speed department, cementing its position as a class leader in terms of outright performance.

However, it’s important to note that top speed isn’t the only factor to consider when choosing a dirt bike. Factors like handling, suspension performance, and overall rider comfort also play a crucial role.

Unlock More Speed

Performance Upgrades

While the KTM 105 SX is plenty fast straight from the factory, there are several upgrades available for those seeking even more speed and performance:

  • Exhaust Systems: Aftermarket exhaust systems from brands like FMF and Pro Circuit can free up additional horsepower and improve throttle response.
  • Air Filters: High-flow air filters from companies like K&N and UNI can increase airflow and boost power output.
  • Engine Internals: For more serious speed gains, internal engine modifications like high-compression pistons, ported cylinders, and performance camshafts can unleash the full potential of the 105 SX’s two-stroke powerplant. However, these modifications often require the expertise of a professional tuner and may void the manufacturer’s warranty. ECU Remapping: For those seeking a simpler solution, an ECU remap or fuel controller can optimize the engine’s fueling and ignition maps, potentially boosting power output without the need for extensive internal modifications.

It’s important to note that while performance upgrades can increase the KTM 105 SX’s top speed, they may also affect other aspects of the bike’s performance, such as fuel efficiency, reliability, and emissions compliance. As always, it’s recommended to consult with a professional and follow all legal regulations.

Cosmetic Customization

While speed and performance are the main attractions of the 105 SX, many owners also enjoy personalizing their ride with cosmetic upgrades. KTM offers a wide range of graphics kits and styling accessories to help you stand out on the track or trail.

Popular options include:

  • Graphics Kits: With designs ranging from bold and aggressive to sleek and understated, KTM’s graphics kits allow you to give your 105 SX a unique look. Kits like the Race Series, Mayhem, and Velocity are among the most popular choices.
  • Colored Plastic Kits: For a more comprehensive makeover, colored plastic kits can replace the bike’s standard bodywork with vibrant hues like orange, blue, or even custom colors.
  • Accessory Upgrades: Additional accessories like anodized brake and clutch levers, colored sprockets, and custom seat covers can add personalized flair to your ride.

Not only do these cosmetic upgrades allow you to express your style, but they can also help protect your investment by refreshing the bike’s appearance and potentially increasing its resale value.

Pros and Cons

To help you make an informed decision, let’s weigh the pros and cons of the KTM 105 SX:


  • Blistering top speed and acceleration for its displacement
  • Nimble handling and precise steering
  • Adjustable ergonomics for a tailored fit
  • Race-inspired components and high-quality construction
  • Extensive customization options for personalization


  • Potential for excessive vibrations, especially on longer rides
  • Sensitive rear brake may require extra modulation
  • Compact dimensions may feel cramped for taller riders
  • Higher maintenance requirements compared to four-stroke bikes
  • More expensive than some competitors in its class

Top Alternatives

If the KTM 105 SX doesn’t quite tick all the boxes for you, here are some top alternatives to consider in the small-displacement off-road segment:

  • Honda CRF150R: A well-rounded and popular choice with a proven track record.
  • Kawasaki KX100: A powerful option with a strong following in the motocross community.
  • Yamaha YZ85: Yamaha’s entry in the big-wheel category, known for its smooth power delivery.
  • Husqvarna TC85: A premium option with a focus on high-end components and performance.

Ultimately, the best choice will depend on your individual riding style, budget, and preferences.

Value Proposition

Despite its impressive performance credentials, the KTM 105 SX manages to strike a balance between speed and affordability. The 2023 model has an MSRP of $5,699 in the United States, making it a reasonably priced option in the premium small-displacement dirt bike market.

It’s important to note that while the initial purchase price may be higher than some competitors, KTM’s reputation for quality construction and performance-focused engineering can potentially translate into a higher resale value down the line.

As for who should consider the 105 SX, this bike is an excellent choice for young or beginner riders looking for a capable and thrilling off-road machine that won’t be outgrown too quickly. Its adjustable ergonomics and manageable power delivery make it a great stepping stone for riders looking to hone their skills before moving up to larger displacement bikes.

Ownership Experience

Common Issues

Like any high-performance machine, the KTM 105 SX does have its share of potential issues that owners should be aware of:

  • Lean Condition: Fresh air leaks, loose intake manifold bolts, or faulty gaskets can cause a lean running condition, leading to poor performance and potential engine damage.
  • Fouled Spark Plugs: Improper jetting or prolonged low-RPM operation can lead to fouled spark plugs, causing misfires and performance issues.
  • Rod Bearing Wear: The 105 SX’s rod bearings may require more frequent replacement compared to some other models, especially under high-stress riding conditions.
  • Brake Pad Wear: The bike’s powerful brakes can lead to accelerated pad wear, necessitating more frequent replacements.

It’s essential to follow the recommended maintenance schedules and address any issues promptly to ensure reliable performance and longevity.

Warranty and Support

KTM offers a 24-month manufacturer’s warranty on the 105 SX, providing coverage for defects in materials and workmanship. However, to maintain warranty coverage, all service and maintenance must be performed by an authorized KTM dealer.

Owners also have the option to extend their warranty coverage by an additional 12 or 24 months before the initial warranty expires, providing up to 12 years or 80,000 km of coverage for added peace of mind.

In terms of support, KTM has a global network of authorized dealers and service centers, ensuring that expert assistance is never too far away.


Can the KTM 105 SX be ridden on the street?

No, the KTM 105 SX is a purpose-built off-road motorcycle and is not street-legal. It lacks the necessary equipment, such as turn signals, mirrors, and lighting, to be legally operated on public roads.

What is the recommended fuel mixture for the KTM 105 SX?

KTM recommends using premium unleaded fuel (91 RON or higher in the USA) mixed with high-grade two-stroke oil at the appropriate ratio, typically around 50:1.

Are aftermarket parts widely available for the KTM 105 SX?

Yes, as a popular model in the motocross and off-road community, there is a wide range of aftermarket parts and accessories available for the 105 SX from various manufacturers, including exhaust systems, air filters, suspension components, and more.

Is the KTM 105 SX suitable for taller riders?

While the 105 SX’s compact dimensions make it an excellent choice for younger or shorter riders, taller individuals may find the ergonomics a bit cramped. It’s always recommended to test-ride the bike to ensure a comfortable fit before making a purchase.

How often should the KTM 105 SX be serviced?

KTM recommends following a regular service schedule based on time or mileage, whichever comes first. Key service intervals include oil and filter changes, valve clearance adjustments, spark plug replacements, and inspections for leaks, wear, and degraded materials.

Final Verdict

The KTM 105 SX is a true speed demon in a compact package, delivering blistering top speeds and acceleration that belie its small displacement. With its potent two-stroke engine, race-inspired components, and agile handling, this little ripper is sure to put a smile on the face of any thrill-seeking off-road enthusiast.

While it may not be the most comfortable or low-maintenance option, the 105 SX’s performance credentials and extensive customization options make it a compelling choice for those seeking an adrenaline-fueled riding experience. Just be prepared to keep up with the maintenance demands and potentially upgrade to a larger displacement bike once you’ve outgrown its pint-sized prowess.

For young or beginner riders looking for a capable and exciting off-road machine that won’t be outgrown too quickly, the KTM 105 SX is an excellent choice that delivers an uncompromising blend of speed, handling, and pure riding enjoyment.

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