By NastyNils·
Motorcycle comparison · Naked Bike
Aprilia Tuono 660 (MY2021) vs KTM 990 Duke (MY2024)
Aprilia Tuono 660 vs KTM 990 Duke: which one to buy, and what actually separates them.
Tip the Aprilia Tuono 660 into a bend and it's turning in off the lightest push on the bar. The KTM 990 Duke's front end talks to you all the way to the apex. Once you've committed, the chassis holds its line.
So which one do you buy?
The 990 Duke has the edge if…
Sporty riding on twisty roads
Nose ahead: 990 Duke
The 990 Duke is a touch more fun when the road starts bending. Thank harder acceleration and more feel through the bars for that.
Daily commuting & city riding
Small edge: 990 Duke
Your daily ride leans slightly toward the 990 Duke. The reason: simpler maintenance. Fit and price can easily outweigh that.
Keeping running costs low
Narrow edge: 990 Duke
Over a year of riding, the 990 Duke noses ahead on running costs. A neglected example would wipe that out.
Which one's the smarter buy
Nothing in it on value
At these used prices, neither bike comes out ahead. The Tuono 660 and 990 Duke cost the same, so the money doesn't pick a winner.
What makes each one tick
Tuono 660
The Tuono 660 doesn't wait to be asked at corner entry, and it swaps sides through the next curve with almost no input. The bars barely move. Underneath, there's a parallel twin with a loping rhythm all its own. The exhaust barks like a V-twin's.
Nils rode the Tuono 660 in 2021, and in Austria in 2023 (NastyNils Testride).
990 Duke
The 990 Duke's riding position works for a hard session and still makes sense on the Monday commute. On the Angeles Crest Highway, its suspension soaks up a broken patch of pavement, and there's enough comfort left for daily miles. With the suspension dialed in, ripples don't kick the bike sideways. The tires stay glued down.
Nils rode the 990 Duke in Austria in 2024 (NastyNils Testride).
The Voice of Experience
What actually separates them
- The 990 Duke makes more peak power: 123 hp (90 kW) vs 95 hp (70 kW).
- The 990 Duke makes more peak torque: 76 lb-ft (103 Nm) vs 49 lb-ft (67 Nm).
- The 990 Duke has the larger engine: 947 cc vs 659 cc.
Which one for the way you ride
Comfortable long-distance riding
Look elsewhere
Long days aren't what these two do best. Plan shorter legs and plenty of stops.
A confidence-building first motorcycle
Not its job: 990 Duke
Too much motor for a beginner: the 990 Duke sits this one out.
Who each one is built for
What's good, and what you'll live with
Tuono 660
What owners say
Strengths
- Light, agile handling
- Refined 270° parallel-twin character
Trade-offs
- Buzzy vibrations around 5,000–6,000 rpm
- Soft, underdamped stock suspension (Standard model)
- Parts availability and dealer density
990 Duke
Strengths
- A Front End You Can Read
- Clean, Predictable Throttle
- Sporty Yet Daily-Usable
- Deep, Usable Electronics
- Engine flexibility across the rev range
Trade-offs
- Notchy, Abrupt Gearshift
- Tight Fit For Tall Riders
- Brakes Are The Weak Link
- Lost the 890 R's playfulness
- Minimal wind protection
Known problems to check before you buy
Tuono 660
- Loose shift lever (early units) and quickshifter false-neutral / "sticky" engagement Two distinct symptoms reported: (a) on early MY2021 units, the shift lever could come loose from the splined shaft within the first ~100 miles and require dealer replacement; (b) the bidirectional quickshifter occasionally produces a false-neutral on upshifts in upper gears at low or partial throttle, or "sticky" cuts during shifts. Rough gear changes at low rpm and partial throttle, smoothing above 5,000 rpm, have also been reported. The loose-lever issue is widely reported on MY2021 and largely resolved on MY2022+ production.
- Snatchy ride-by-wire fueling on throttle transitions Closed-throttle to roll-on transitions exhibit a touchy, jerky character widely reported in launch-year reviews. Cold-weather behavior below approximately 54°F (12 °C) ambient adds occasional hesitation or misfires until the engine warms. The character is most pronounced in the more aggressive ride modes. Reports diminish in MY2022+ coverage relative to MY2021.
- Water-pump mechanical seal weep at low mileage Coolant or engine oil drip from the water-pump weep hole, sometimes presenting as early as 150–250 miles. Recurring early-ownership theme on Aprilia owner forums. The coolant-side variant sometimes self-clears as the seal beds in; the oil-side variant requires teardown of the flywheel cover and seal replacement, normally completed under warranty.
- Aprilia MIA module pairing failures and dashboard firmware quirks When the optional Aprilia MIA Multimedia Platform (PMP 3.0) module is fitted, owners report Bluetooth pairing failures, the phone icon remaining greyed out, inaccessible submenus, and music interruption when paired comms are active. Several owners report a fix only after a dealer-side dashboard firmware update via the Piaggio PADS diagnostic tool.
- Cosmetic finish and fastener corrosion complaints Recurring small complaints across reviews and forums: matte/satin tank paint is thin and scratch-prone; visible fasteners surface-corrode in year-round use; belly-pan plastic feels rough relative to price tier; decals work loose over time; minor rear-brake squeak reported. None are structural problems and all are cosmetic in nature, but they are widely cited as detracting from the bike's premium positioning.
990 Duke
No confirmed faults on file yet. That's not the same as fault-free.
What they cost used
These prices compare a 2-year-old Tuono 660 with a 2-year-old 990 Duke.
- Tuono 660
- $9,900
- 990 Duke
- $9,900
What they share
- Engine
- Parallel twin
- Cooling
- Liquid-cooled
- Gearbox
- 6-speed
- Final drive
- Chain
- Front tire
- 120/70-17
- Rear tire
- 180/55-17
Where the spec sheets split
| Tuono 660 | 990 Duke | |
|---|---|---|
| Seat height | 32.3 in (820 mm) | 32.5 in (825 mm) |
| Dry weight | 373 lb (169 kg) | 395 lb (179 kg) |
| Tuono 660 | 990 Duke | |
|---|---|---|
| Displacement | 659 cc | 947 cc |
| Power | 95 hp (70 kW) | 123 hp (90 kW) |
| Peak power at | 10,500 rpm | 9,500 rpm |
| Torque | 49 lb-ft (67 Nm) | 76 lb-ft (103 Nm) |
| Peak torque at | 8,500 rpm | 6,750 rpm |
| Tuono 660 | 990 Duke | |
|---|---|---|
| Fuel economy | 48 mpg (US) / 4.9 L/100 km | 50 mpg (US) / 4.7 L/100 km |
| Fuel capacity | 4.0 US gal (15 L) | 3.9 US gal (14.8 L) |
| Tuono 660 | 990 Duke | |
|---|---|---|
| Wheelbase | 53.9 in (1370 mm) | 58.1 in (1476 mm) |
What comes fitted, what costs extra
| Tuono 660 | 990 Duke | |
|---|---|---|
| USB Charging Port | Option | Standard |
Head to head, area by area
Both bikes on the same scale, one area at a time.
