2017–2021 · Supersport · Buyer's Guide
One Cylinder, All Attack
KTM built the RC 390 around one idea: make a small bike feel like a real race machine everywhere it counts. The 373 cc liquid-cooled single makes 45 hp at 9,500 rpm and 26 lb-ft at 7,000 rpm, and it wants to live near the top of that range. Around it sits a steel trellis frame, an upside-down fork, a 320 mm front disc, a slipper clutch and a 6-speed box, with ABS as the electronic safety net. On paper it is a small supersport. On the road it behaves like a scaled-down one, which is exactly the point.
The character sorts buyers fast. This bike rewards riders who carry corner speed, hold a clean line and keep the revs up, and it stays composed as the pace climbs. Running costs are low and the aftermarket is deep, so it takes modification well as your skills grow. The caveats are just as real. The fork has no adjustment at all, only the shock takes preload, and ABS is the extent of the rider aids. The 2.5 gal (9.5 L) tank keeps rides short, and the radiator fan is the known weak spot on this generation.
Spec sheets don't ride bikes, but they set the baseline.
| Power | 45 hp (33 kW) @ 9,500 rpm |
|---|---|
| Torque | 26 lb-ft (35 Nm) @ 7,000 rpm |
| Displacement | 373 cc |
| Engine | Single-cylinder |
| Cooling | Liquid-cooled |
| Gearbox | 6-speed |
| Final drive | Chain |
| Fork | Upside-down (USD) |
| Front brake | 320 mm |
| Front tire | 110/70-17 |
| Rear tire | 150/60-17 |
| Wheelbase | 52.8 in (1340 mm) |
| Seat height | 32.3 in (820 mm) |
| Fuel capacity | 2.5 gal (9.5 L) |
Equipment check
Chassis
Drivetrain
Safety
Premature radiator fan failure
The radiator fan is prone to early failure, which can cause overheating in traffic or during track use. Replacement with an upgraded unit is a common fix.
Where this KTM RC 390 pulls ahead of — or falls behind — its rivals on the numbers, and the typical bike in its class on character.
Power
Torque
Displacement
Seat height
Forget spec-sheet bragging. Here's who the RC 390 is actually built for.
On Angeles Crest this bike is about corner speed, not horsepower. It turns in instantly and leans hard without grinding, so you ride the road instead of the throttle. Sitting in LA traffic is the price.
Made for Angeles Crest Highway · Coronado Trail / US 191 · Highway 1 / Big Sur
For the Dragon and Cherohala it works as a skill tool. Light steering and stable manners at speed let you chase line accuracy run after run, as long as you plan around the small tank.
Made for Back of the Dragon · Blue Ridge Parkway · Cherohala Skyway
The Hill Country curves suit it; the long straight slog out of Austin does not. Short range and a firm seat keep days compact, so treat it as a local weapon, not a roadtrip bike.
Made for Austin / Texas Hill Country · Twisted Sisters · Austin / Handbuilt Motorcycle Show
If you're cross-shopping the older generation, here's what changed.
Previous generation · 2014
Corner Entry On Repeat
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 RC 390. “cheaper/pricier” is what that bike costs second-hand, not how worn it is.
Successor · 2022–2024
The A2 Corner Carver
Competitor · 2019–2024
Light, Sharp, Rev It Hard
About the same used price as this bike at 6 yr
Competitor · 2018–2024
Light Weight, Sharp Lines
Roughly $700 cheaper used than this bike at 6 yr
Same Platform · 2017–2023
Small Orange, Maximum Attack
About the same used price as this bike at 5 yr