Quick Analysis
KTM 50 SX
3.5 pts
Unweighted: 2 advantages
EnginePerformanceDimensionsBrakesTyresFeaturesOther
KTM 390 DUKE
30.0 pts
Unweighted: 23 advantages
EnginePerformanceDimensionsBrakesTyresFeaturesOther
| Specification | ||
|---|---|---|
Engine Specifications |
||
| Cooling System | — | Liquid cooling with radiator |
| Displacement | 49.9 cc | 398.63 cc |
| Engine Type | 1-cylinder, 2-stroke engine | Single Cylinder, Liquid Cooled, DOHC, FI Engine |
| Power | 5.3 bhp @ 11500 rpm | 33.8 kW @ 8500 rpm |
| Torque | 5.2 Nm @ 7500 rpm | 39 Nm @ 6500 rpm |
Performance & Efficiency |
||
| Fuel Tank Capacity | 2.3 L | 15 L |
| Mileage | 30 kmpl | 30 kmpl |
Dimensions & Weight |
||
| Kerb Weight | 41 kg | 168.3 |
| Seat Height | 653 mm | 820 |
Brakes & Suspension |
||
| ABS | — | Dual-channel ABS with SUPERMOTO mode |
| Front Brake | Disc 160 mm | 320 mm Disc with Radially mounted calliper |
| Front Suspension | XACT 35 WP Upside-Down fork, Ø 35 mm | 5-click Compression & Rebound adjustable, Open Cartridge, WP APEX USD forks, 43mm diameter |
| Rear Brake | Disc 160 mm | 240 mm Disc with Floating calliper |
| Rear Suspension | XACT WP mono shock | Adjustable WP APEX Monoshock, 5-step Rebound damping, 10-step preload adjustable |
Tyres & Wheels |
||
| Front Tyre | 60/100 - 12 | 110/70 - ZR17 |
| Rear Tyre | 2.75 - 10 | 150/60 - ZR17 |
| Tyre Type | Tubed | Tubeless |
| Wheel Type | Spoke | Alloy |
Features & Technology |
||
| Headlight | — | Full Split LED Headlamp |
Other Specifications |
||
| Battery | — | 12 V, 8 AH MF battery |
| Bike Image 1 | — | https://motoautiv.com/wp-content/uploads/2025/11/KTM-390-Duke-Electric-orange.webp |
| Bike Image 2 | — | https://motoautiv.com/wp-content/uploads/2025/11/KTM390DukeBlack_Booking.webp |
| Cluster | — | 5" TFT dash display |
| Color Options | Electronic Orange | GUN METAL GREY | #4A4F55, #FF6600 ELECTRONIC ORANGE | #FF6600 ATLANTIC BLUE | #2F5D7C, #FF6600 |
| Cons | High Maintenance: As a 2-stroke engine, it requires frequent servicing and tuning. Small Fuel Tank: Limited capacity means more frequent refills. Kick-Start Only: No electric start, which can be tricky for very young riders. Limited Power for Older Kids: The 50cc engine may not be enough as the rider grows or becomes more skilled. Sensitive to Tuning: Owners report issues like fouling spark plugs or needing to frequently re-jet the carb: “Used to run great … then started fowling plugs … Moved to a 95 main jet … About 15 kph slower …” Parts Cost & Availability: As a race‑oriented bike, some parts can be expensive or harder to source for older models. | Firm (harsh) ride: The suspension can feel stiff over potholes or uneven surfaces, which may be tiring for long rides. Limited wind protection: Being a naked bike, you feel a lot of wind at highway speeds, making long-distance touring less comfortable. Engine heat: In slow or stop-go traffic, the radiator fan can dump hot air toward the rider’s legs, which many find uncomfortable. Seat comfort: The stock seat can feel firm and less comfortable for long rides; also, pillion comfort is limited. Vibration: Some riders report noticeable vibrations in certain RPM ranges, especially between ~4,500–6,000 rpm. Reliability concerns: There are occasional reports of reliability issues or quality control, especially in older models. |
| Detailed Overview | The KTM 50 SX is a purpose-built mini motocross bike, tailored primarily for very young and beginner racers who want to get a genuine motocross experience without jumping straight to bigger bikes. It’s more than just a “toy” — KTM has packed serious race-bike DNA into this 50cc model, making it a standout choice for youth motocross training and competitive racing. At the heart of the 50 SX is a 49.9 cc single-cylinder 2-stroke engine, which delivers a punchy yet manageable power output. According to KTM’s specs, this engine is paired with a centrifugal automatic clutch, meaning there’s no manual clutch lever to worry about — the clutch engages automatically, which is ideal for young riders still building coordination and confidence. The engine uses a Seletra 2p D36 system for fuel delivery (on some models), which helps in precise tuning and reliable performance. KTM has thoughtfully designed the chassis for both strength and agility. The frame is made from chromoly steel, which keeps it light but sturdy. The overall design ensures that the bike is highly maneuverable, making it easier for young riders to learn balance and control on a real race-ready structure. The 50 SX isn’t just about motor and frame — it comes with serious suspension too: a WP XACT 35 mm upside-down fork at the front and a WP mono‑shock at the rear.The front suspension travel is around 200 mm and the rear is close to 190 mm, giving enough give for track bumps and jumps. In terms of ergonomics, the seat height is just 653 mm, making it very accessible for younger riders. Ground clearance is around 233 mm, giving the bike enough space to handle uneven terrain without scraping too much.The fuel tank capacity is modest — 2.3 liters — but that’s more than enough for short motocross sessions that young riders typically do. For braking, KTM hasn’t compromised: the 50 SX is equipped with disc brakes both front and rear, each 160 mm in size. This provides good stopping power and control, which is very important for safety and learning advanced braking techniques. On the wheels front, the bike uses spoke wheels, keeping things light and rugged for off-road racing. Despite its small size, the 50 SX is very race-focused. The frame has been redesigned to mimic the flex and rigidity characteristics of full-size MX bikes. The new frame also comes with frame protectors, which help reduce damage in case of falls — a common occurrence when young riders are learning. The handlebars are lightweight aluminum, with a bend that suits smaller riders, and the footpegs are designed to give a solid grip even when things get muddy or rough. KTM also includes power-reduction kits in its parts catalog for the 50 SX. These kits let parents or coaches limit the power output while the rider is still learning, which is a smart way to scale the bike’s performance to the rider’s ability — and once they’re better, the full power can be unlocked. When it comes to reliability, the 50 SX has a liquid cooling system for better thermal management. The engine’s central crankshaft design helps in keeping the mass well-balanced, which contributes to smoother handling. As for maintenance, like all 2-stroke motorcycles, it does need regular care — but KTM has made key parts (like the clutch) durable, using a reinforced clutch basket for longevity. Overall, the KTM 50 SX is a very well-engineered youth motocross bike that brings real race performance to younger riders. It balances power, weight, and control in a way that helps beginners grow into serious racers. Whether for track training, competitive racing, or just building early riding skills, it’s absolutely one of the top choices in the mini-moto world. | The KTM 390 Duke is built with a layout that focuses on keeping the bike compact while still offering strong performance for its size. It uses a 399cc, single-cylinder, liquid-cooled engine that produces around 45–46 bhp and close to 39 Nm of torque. The engine is paired with a 6-speed gearbox and comes with a slipper clutch and a quickshifter, which help make gear changes smoother in both city traffic and faster riding conditions. The throttle is controlled electronically through a ride-by-wire system, which adjusts how the engine responds to inputs. The bike is based on a steel trellis frame that works along with a lightweight subframe to keep the structure balanced. With a kerb weight of around 168 kg, it remains relatively light, which affects how easily it moves in traffic and how quickly it responds to steering inputs. The fuel tank capacity is about 15 litres, and the seat height is close to 800 mm, making it manageable for a wide range of riders. The riding position is upright with a slight forward lean, supported by a wide handlebar. Suspension is handled by WP Apex units, with upside-down forks at the front and a monoshock at the rear. Both ends are adjustable, allowing changes based on riding conditions. The bike runs on alloy wheels with wide tyres, which influence grip and stability during cornering as well as everyday riding. The setup is designed to maintain control without making the ride feel too soft. Braking is managed by a single disc at the front and a disc at the rear, supported by dual-channel ABS. The system also includes cornering ABS, which adjusts braking force based on the bike’s lean angle. These systems work automatically and are meant to provide stability in different riding situations without requiring constant input from the rider. The electronics package includes a TFT display that shows speed, fuel level, ride modes and other basic information. It also supports smartphone connectivity and allows the rider to switch between different riding modes, which change throttle response and system intervention levels. Features like traction control are also included, reflecting the level of technology now available in this segment. The design follows a sharp and compact naked bike style, with minimal body panels and exposed elements around the frame and engine. The tank, panels and overall proportions give it a tight and focused appearance. While many bikes in this category try to balance multiple roles, the 390 Duke’s setup keeps things centered around a specific type of riding, and that focus is visible in how its engine, chassis and features are put together. |
| Expert Review | MotoAutiv Team | In a segment where most motorcycles are expected to manage daily commuting along with occasional highway use, the KTM 390 Duke takes a slightly different direction. Its 399cc single-cylinder engine produces around 45–46 bhp and close to 39 Nm of torque, placing it among the more performance-focused options in its category. At the same time, changes in the latest version have made the power delivery smoother at lower speeds, which helps in typical city traffic conditions. The lightweight chassis and compact design make it easier to handle in tight spaces, something that suits Indian roads where traffic and road conditions can vary a lot. It also includes features like ride modes, traction control and a TFT display, reflecting how buyer expectations in this segment have evolved over time. In the broader context, the bike shows how the Indian market is gradually moving towards motorcycles that combine everyday usability with a stronger focus on performance and technology., 4.4, MotoAutiv Team |
| FAQ (Manual Override) | Q: What is the engine capacity of the KTM 50 SX? A: It has a 49.9 cc 2-stroke engine. Q: What kind of transmission does it use? A: The KTM 50 SX has a single-speed automatic transmission. Q: How is the KTM 50 SX started? A: It uses a kick-start. Q: Does it have a clutch? A: Yes — a centrifugal (adjustable) clutch, so the rider doesn’t have to use a manual clutch lever. Q: What is the fuel tank capacity? A: The fuel tank capacity is 2.3 litres. Q: What is the seat height? A: The seat height is 653 mm. Q: What is the weight of the bike? A: The dry (or “without fuel”) weight is about 43.5 kg for recent models. Q: What kind of suspension does the KTM 50 SX use? A: It comes with WP XACT suspension — a 35 mm upside-down fork in the front and a WP mono-shock at the rear. Q: What brakes does it have? A: It has disc brakes both at the front and rear, each 160 mm. Q: What power does the KTM 50 SX produce? A: The KTM 50 SX produces around 5.3–5.4 PS at ~11,500 rpm. Q: Is the KTM 50 SX road legal? A: No — it's designed for off-road / motocross use, not for street-legal riding. Q: What kind of clutch does it have for young riders? A: It uses a centrifugal clutch, which automatically engages at high RPM — good for beginners or young riders who don’t manually operate a clutch. Q: What is the ground clearance? A: The ground clearance is 233 mm. Q: Is there a guarantee or warranty for KTM 50 SX? A: According to specs, it has a 2-year standard warranty. Q: What is the typical maintenance challenge or issue to watch for? A: Some owners report carburetor tuning issues | Q: What engine does the KTM 390 Duke have? A: It uses a single-cylinder, liquid-cooled, DOHC engine. Q: What is the displacement, power & torque of the 390 Duke? A: The displacement is about 398.6 cc. In the newer versions, it produces around 46 PS at 8,500 rpm and 39 Nm of torque at 6,500 rpm. Q: What is the seat height and weight of the 390 Duke? A: The seat height is 800 mm (or optionally 820 mm) depending on the version. The kerb weight is about 168.3 kg per KTM’s specification. Q: What is the fuel tank capacity and what is the mileage like? A: The fuel tank capacity is 15 litres in many versions. According to some sources, real-world fuel efficiency is around 25–30 km/l, depending on riding style. Q: What brakes and suspension does it use? A: It comes with WP APEX 43 mm upside-down front forks and a WP APEX monoshock at the rear. For brakes, there is a 320 mm front disc and a 240 mm rear disc, with a radially mounted caliper up front. Q: What is the ground clearance of the 390 Duke? A: The ground clearance is around 183 mm according to KTM India specifications. Q: What is the seat configuration and ergonomics like? A: It has a two-part seat design, with a slightly aggressive but comfortable rider position thanks to its upright handlebars. There’s also a “Supermoto mode” which lets you limit ABS intervention to the front brake, great for sliding control. Q: Does the 390 Duke come with smartphone connectivity? A: Yes, some variants support KTM MY RIDE via the 5-inch TFT dash, allowing for calls, music, and navigation integration. |
| Fuel System | — | Fuel Injection |
| Price Variants | | 475000 | Standard | 339002 |
| Pros | Very Lightweight: Makes it easy for young riders to handle and build confidence. Automatic Transmission: The centrifugal clutch and automatic gearbox simplify riding for beginners. Adjustable Suspension: High-quality WP fork and shock can be tuned to rider weight and track conditions. Racing‑Oriented Build: Frame and components are derived from KTM’s full-size SX range, giving a race-ready feel. Power-Reduction Kits Available: Helps beginners by limiting power until they’re ready for more. Good Cooling: Liquid cooling ensures the engine stays healthy even under hard off‑road use. Tool-Free Adjustability: Seat height, suspension, and other parts can be adjusted without special tools. | Excellent performance for its class: The 390 Duke’s single-cylinder engine delivers punchy acceleration and strong mid-range performance. Lightweight & nimble: With a relatively low kerb/wet weight, its chassis is very agile, making it easy to flick through corners and manoeuvre in traffic. Advanced electronics suite: Comes equipped with ride modes, traction control (MTC), cornering ABS, supermoto ABS, quickshifter, and a modern TFT display. Adjustable suspension: The front and rear suspension are adjustable (WP APEX), allowing riders to tune the setup depending on road conditions or riding style. Sharp styling & design: Features such as an exposed steel trellis frame, LED headlight, and aggressive design make it visually striking. Good build quality: Reviews note improved fit and finish on newer models, giving a premium feel. Decent fuel efficiency: Compared to its performance, it offers reasonable fuel efficiency for sporty riding. |
| Starter | — | Self Start Only |
| Transmission | Manual | 6 Speed Manual |
