KTM 790 Duke (2017–2020): The Scalpel’s Surgical Precision

Introduction

Dubbed “The Scalpel” by its creators, the KTM 790 Duke (2017–2020) is a masterclass in agility, precision, and raw excitement. Designed to carve corners with the finesse of a track tool while retaining everyday usability, this middleweight naked bike redefined expectations for performance and electronics in its class. After spending time with this orange menace, it’s clear why riders still seek it out—whether for weekend twisties, commutes, or track-day bragging rights. Let’s dissect what makes this generation of the 790 Duke a modern classic.

Engine Performance: Twin-Cylinder Thrills

At the heart of the 790 Duke lies KTM’s first parallel-twin engine, the LC8c (liquid-cooled, 799 cc). This compact powerhouse churns out 105 HP (77 kW) at 9,000 rpm and 87 Nm (64.2 lb-ft) of torque at 8,000 rpm, delivering a linear yet exhilarating powerband. The engine’s 75-degree crank offset and 435-degree firing order give it a distinctive growl, blending the urgency of a V-twin with the smoothness of an inline-four.

Key Highlights:
- PASC Slipper Clutch: Ensures seamless downshifts and prevents rear-wheel hop during aggressive braking.
- Quickshifter+: Standard up/down shifts let you keep the throttle pinned, whether accelerating out of a corner or chasing redline.
- Throttle Response: Ride-by-wire fueling serves up instant punch in “Sport” mode, while “Rain” mode tames the chaos for slippery conditions.

Riding the 790 Duke feels like conducting an orchestra—every twist of the wrist elicits a symphony of mechanical harmony. The engine thrives on revs, but its mid-range torque (peaking at 8,000 rpm) makes overtaking effortless. Even at highway speeds, the twin remains vibration-free, a testament to its dual balancer shafts.

Chassis & Handling: Lightweight Precision

Weighing just 169 kg (372.6 lbs) dry, the 790 Duke’s chromoly steel frame and aluminum subframe prioritize stiffness without bulk. Paired with a 24-degree rake and 98 mm (3.8 in) trail, the geometry strikes a balance between flickable agility and high-speed stability.

Suspension & Brakes:
- WP USD Forks (43 mm): Non-adjustable but tuned for progressive damping—soft enough for potholes, firm enough for hard braking.
- WP Rear Shock: Preload-adjustable with 150 mm (5.9 in) of travel, offering plush compliance over bumps.
- Braking Setup: Dual 300 mm front discs with radial-mount J.Juan calipers (ABS-equipped) provide strong, predictable stopping power.

The Duke’s Maxxis Supermaxx ST tires (120/70-17 front, 180/55-17 rear) warm up quickly and offer surprising grip, even in wet conditions. For track enthusiasts, swapping to stickier rubber unlocks even leaner angles—though the stock setup already encourages knee-down heroics.

Electronics Suite: Brain Meets Brawn

KTM loaded the 790 Duke with tech that rivals flagship superbikes:
- Cornering ABS & Supermoto Mode: Disengage rear ABS for slides while retaining front intervention.
- Motorcycle Traction Control (MTC): Lean-sensitive and adjustable across 10 levels (in “Track” mode).
- 4 Riding Modes: “Street,” “Rain,” “Sport,” and customizable “Track” settings.
- TFT Dashboard: A vibrant 5-inch display shows gear position, lean angles, and even a color-shifting tachometer.

These features aren’t just gimmicks—they’re lifelines. During a sudden downpour, switching to “Rain” mode dulled throttle response and boosted traction intervention, keeping the rear tire firmly planted.

Ergonomics: Confidence for All Riders

The 790 Duke’s 825 mm (32.5 in) seat height accommodates shorter riders, while its narrow profile and tapered aluminum handlebar (adjustable in 4 positions) create a natural, upright stance. Despite minimal wind protection, the riding position is comfortable for hours—though highway speeds above 130 km/h (80 mph) turn your torso into a sail.

Practical Touches:
- 14-Liter Fuel Tank: Small for touring, but the Duke sips fuel efficiently (avg. 4.5 L/100 km or 52 MPG).
- LED Lighting: The signature “face mask” headlight pierces night rides, while the minimalist taillight is easy to remove for track days.

Competition: Middleweight Showdown

The 790 Duke’s rivals are formidable, but here’s how it stacks up:

1. Triumph Street Triple 765 RS

• Pros: Refined triple-cylinder engine, premium Showa/Brembo components.
• Cons: Higher price tag, less playful electronics.
• Verdict: The Street Triple is a smoother operator, but the Duke’s raw agility and tech suite make it more thrilling.

2. Yamaha MT-09

• Pros: Iconic CP3 engine, lower cost.
• Cons: Soft suspension, basic ABS/traction control.
• Verdict: The MT-09 is a hooligan, but the Duke out-handles it and offers finer electronic control.

3. Ducati Monster 821

• Pros: Italian flair, V-twin character.
• Cons: Heavier, pricier maintenance.
• Verdict: The Monster charms with style, but the Duke dominates in weight savings and tech.

Maintenance: Keeping The Scalpel Sharp

Ownership costs are reasonable, but adherence to service intervals is critical:

Key Recommendations:
- Engine Oil: Use SAE 10W-50 (2.8 L with filter). Change every 10,000 km (6,200 mi).
- Chain: Clean and lubricate the 520 X-ring chain every 500 km (310 mi). MOTOPARTS.store offers premium kits for longevity.
- Tire Pressures: 2.3 Bar (33 PSI) front / 2.6 Bar (38 PSI) rear for optimal grip and wear.
- Brake Fluid: Flush with DOT 4 or 5.1 every 2 years.
- Coolant: Replace every 24,000 km (15,000 mi) using high-quality ethylene glycol-based fluid.

Upgrade Tips:
- Swap to aftermarket sprockets (16/41) for quicker acceleration.
- Install heated grips or a tail tidy from MOTOPARTS.store to enhance functionality.

Conclusion: A Modern Benchmark

The KTM 790 Duke isn’t just a motorcycle—it’s a precision instrument. From its razor-sharp handling to its tech-laden cockpit, every detail screams “performance.” While rivals offer more comfort or lower costs, none match the Duke’s ability to thrill on backroads and behave in traffic. For riders seeking a middleweight that punches above its weight, The Scalpel remains a cut above the rest.

Ready to elevate your 790 Duke? Explore MOTOPARTS.store for upgrades, maintenance kits, and accessories tailored to your ride.

Specifications sheet