2018 · Naked Bike · Buyer's Guide
The Scalpel Hits Its Mark
KTM's LC8c era starts here. The 799 cc parallel twin runs a 285-degree crank that gives it the lumpy, off-beat pulse of a V-twin instead of the flat hum most twins settle into, and it makes a genuine 105 hp with 64 lb-ft underneath. Wrapped in a light steel trellis frame, it earned the Scalpel name honestly: the geometry is set up to drop into a corner the instant you think about it. The electronics are real KTM kit too, with Motorcycle Traction Control and Ride-by-Wire running Street, Track, and Rain maps. For a naked middleweight, this was the sharp benchmark of its moment.
The 790 rewards a rider who wants to feel the machine working under them rather than be insulated from it. At 417 lb (189 kg) wet it changes direction almost telepathically, and the 32.5 in (825 mm) seat keeps the riding position aggressive without punishing you in traffic. It fits the canyon and back-road rider who values precision over outright power. The honest caveat: the fork is fixed and the shock only takes preload, so there is little dialing the suspension in for your weight or pace. And the early LC8c motor needs its valve checks taken seriously, because soft cam lobes can show up around 12,000 to 19,000 mi (20,000 to 30,000 km).
Spec sheets don't ride bikes, but they set the baseline.
| Power | 105 hp (77 kW) @ 9,000 rpm |
|---|---|
| Torque | 64 lb-ft (87 Nm) @ 8,000 rpm |
| Displacement | 799 cc |
| Engine | Parallel twin |
| Bore × stroke | 88 × 65.7 mm |
| Cooling | Liquid-cooled |
| Gearbox | 6-speed |
| Final drive | Chain |
| Frame | Steel trellis |
| Front tire | 120/70-17 |
| Rear tire | 180/55-17 |
| Seat height | 32.5 in (825 mm) |
| Wet weight | 417 lb (189 kg) |
| Fuel capacity | 3.7 gal (14 L) |
| Fuel economy | 53 mpg (US) |
Equipment check
Connectivity
Drivetrain
Lighting
Safety
Swing a leg over and the first thing you notice is how slim it feels between your knees, narrow and tall enough that your weight sits forward over the front wheel where KTM wants it. Thumb the starter and that 285-degree beat thrums through the bars and pegs at idle, a deliberate, mechanical pulse you feel as much as hear. Out on a real road the bike feels lighter than its numbers, tipping side to side with barely a nudge on the bars, and the upright stance lets the wind push at your chest the way a good naked should, making 60 mph feel busy and alive. The seat keeps you in one comfortable spot for canyon work, though there is genuine buzz through the bars up near the top of the rev range. Roll the throttle on and the whole thing leans into the effort with you.
Premature camshaft wear
The LC8c engine can suffer from soft cam lobes, leading to excessive wear and potential engine damage. Typically noticed at 20,000–30,000 km during valve checks.
Coolant hose leaks
The round radiator hoses do not seal well against the oval thermostat housing, causing coolant leaks. Common on 2018-2020 models.
Immobilizer malfunction
In cold weather or with a weak battery, the immobilizer may trigger a warning on the dash and prevent starting. Replacing the battery often resolves the issue.
Thermostat housing leak
The thermostat housing lacks a separate gasket, allowing small debris to accumulate and cause leaks. Difficult to diagnose without removal.
Valve cover gasket leak
The valve cover gasket can leak oil from the half-moon seals due to insufficient factory sealant. Often appears around 14,000 km and may eventually affect all early bikes.
Where this KTM 790 Duke pulls ahead of — or falls behind — its rivals on the numbers, and the typical bike in its class on character.
Power
Torque
Displacement
Wet weight
Seat height
Forget spec-sheet bragging. Here's who the 790 Duke is actually built for.
If your weekends are Angeles Crest and tight Westside passes, this is a precise, light tool that rewards clean lines. You will love the agility; just keep up on valve checks if you buy used.
Made for Angeles Crest Highway · Coronado Trail / US 191 · Highway 1 / Big Sur
For repeated laps of the Dragon and the Cherohala, where skill beats speed, the 790 is ideal: featherweight steering and big lean clearance let you focus on technique, not muscling the bike.
Made for Back of the Dragon · Blue Ridge Parkway · Cherohala Skyway
Commute the city, meet up at Alice's, then carve the ridge roads. The 790 handles all three with a sharp look and easy handling, and its strong aftermarket lets you make it yours.
Made for Bay Area Ridge Roads · San Francisco / Bay Area · Skyline Boulevard / Alice's Restaurant
If you're cross-shopping the older generation, here's what changed.
Previous generation · 2016–2019
Single Cylinder Scalpel On Street
Compare to the previous model →If this one isn't quite the fit, these are the bikes worth riding back-to-back against it.
Any price note compares both bikes at the same age — the youngest age both have on the used market — against this KTM 790 Duke. “cheaper/pricier” is what that bike costs second-hand, not how worn it is.
