KTM 790 Duke 0-60 mph in 3.07 seconds
KTM’s Duke series has been with us since 1994, when it first appeared as the 620 Duke supermotard.
Since then it has gone through many different versions over the years.
As most people know, KTM started life as a dirt bike manufacturer and has enjoyed considerable success both off-road and on the track.
Their dirt bikes appear to have followed a kind of Darwinian evolution over the past twenty-plus years.
Some models have developed from pure dirt bike singles into supermotard singles, then into naked twins, and even full Superbikes in the form of the RC8.
KTM now also competes at the highest level in MotoGP.It has been an impressive journey for the Austrian manufacturer.
Today, the Duke series continues to thrive in multiple engine configurations. One of the more recent additions is the KTM 790 Duke.
Released in 2018, this sporty naked motorcycle is powered by a compact 799 cc parallel-twin engine producing a claimed 105 horsepower.
Naked bikes have become the new Superbikes.
In recent years, they have grown hugely in popularity, largely because they offer similar levels of performance and fun to full-on Superbikes in many situations, yet remain far more practical and comfortable for everyday riding and urban use.
While the 790 Duke does not possess the raw power of a Superbike, it hits that magical “all you need on the road” figure of 100 horsepower. In all but the most extreme circumstances, that is genuinely enough.
Combine that with its light weight and excellent handling, and you have a very capable motorcycle that consistently punches well above its weight.
KTM 790 Duke dyno curve and engine performance
Parallel-twin engines rarely get much love in the motorcycle world.
There is nothing inherently wrong with them. In fact, they are compact and relatively cheap to produce.
However, they are often used in budget or learner motorcycles precisely for those reasons.
As a result, parallel-twins are frequently found in small-capacity machines and are usually tuned for learner-friendly power delivery.
On top of that, conventional parallel-twins do not have a particularly inspiring sound, which can be a turn-off for many enthusiasts.
o address this, some manufacturers have started using offset crankshafts to give their parallel-twins more character.
Yamaha was one of the early adopters with the TRX 850, and more recently, the MT-07 with its 270° crank.
KTM has taken a different approach with a 485° crank on the 790 Duke. This gives the engine a firing order that makes it sound remarkably similar to KTM’s own 75° V-twin engines used in larger models.
In effect, the 790 Duke delivers the character and sound of a 75° V-twin, but packaged as a parallel-twin.
So why not just build a proper 75° V-twin? The answer is simple: parallel-twin engines are cheaper to manufacture, physically shorter, and still very narrow, making them far easier to package in a compact chassis.
KTM790 Duke Theust Curve
They can be tall when used in very large capacities, but this can be largely offset if the engine is an oversquare, short-stroke design. A genuine win-win.
The KTM 790 Duke produces a very respectable 96 horsepower at 9,000 rpm, with peak torque of 58 ft-lb arriving at 6,500 rpm.
These are strong figures from an 799 cc parallel-twin, although the power curve is still climbing right up to the rev limiter, which cuts in abruptly just before 10,000 rpm.
That seems quite low for a modern two-cylinder engine with relatively big pistons.
It feels as though KTM has been deliberately conservative. I am confident this engine could easily rev to 11,000 rpm and deliver around 105 horsepower at the rear wheel.
Despite the relatively low redline, the engine is still excellent.
It is smooth, responsive, and offers a good spread of power and torque, with a pleasing surge as the revs approach 6,000 rpm.
Thanks to very lightweight internals and short gearing in the first three gears, the 790 Duke builds revs extremely quickly, often feeling like a bike with considerably more power.
While there is plenty of low-down grunt, the engine truly comes alive between 6,500 rpm and just over 9,000 rpm.
This is not the widest powerband in the class and is narrower than some key rivals such as the Yamaha MT-09, Kawasaki Z900 or Triumph Street Triple 765.
Those bikes are either less rev-dependent or have a much broader usable rev range.
Even so, the KTM 790 Duke is surprisingly quick for a two-cylinder naked bike. In general, four-cylinder engines of similar capacity tend to rev noticeably higher than parallel-twins.
Even when a two-cylinder engine produces the same peak power as a four-cylinder, the four-cylinder unit will almost always rev higher.
That extra rev range gives designers the option to use lower gearing without sacrificing top speed in each gear.
Here is a simple example: imagine two engines both making the same power at 10,000 rpm.
One is a two-cylinder with a rev limit of 10,500 rpm, while the other is a four-cylinder with a rev limit of 11,500 rpm.
Because the four-cylinder can rev 1,000 rpm higher, the designer can choose gearing that is roughly 10% lower.
This still allows the four-cylinder to reach the same maximum speed in each gear as the two-cylinder, but it now delivers around 10% more thrust at any given road speed.
If the four-cylinder makes slightly less power and torque across the rev range, this shorter gearing can effectively cancel out the deficit.
To compensate for their lower rev limits, two-cylinder performance motorcycles typically run shorter gearing in the first three gears and taller gearing in the top three.
This is exactly why a modern 600 cc Supersport can often match or even beat a late-1990s or early-2000s 1000 cc L-twin in a top-gear roll-on, despite having roughly half the torque.
Thanks to the huge rev differential (600s routinely exceed 15,000 rpm while the old twins peaked just under 11,000 rpm), the average 600 cc Supersport’s sixth-gear ratio is roughly equivalent to fourth gear on those older 1000 cc twins.
KTM 790 Acceleration through the Gears
Like many two-cylinder bikes, the KTM 790 Duke has to live with the disadvantage of not revving as high as its three- or four-cylinder rivals. It also revs lower than many larger-displacement twins.
Despite this, it still puts down some very impressive numbers.
As with most electronic rider aids, such as traction control and anti-wheelie systems, they can help you achieve more consistent times, especially if you are of average skill.
However, if you have a few traffic-light Grand Prix wins under your belt, your quickest times will almost always come with all the aids switched off.
With the electronics disabled, the 790 Duke is exceptionally quick off the line, recording an excellent 3.07 seconds for 0-60 mph and 3.16 seconds for 0-100 km/h, impressive figures considering it requires a gear change to reach 60 mph.
To achieve these times, you need fine control of the bike’s eager wheelie tendency through precise clutch and throttle work, while shifting as much of your weight over the front as expertly as possible.
Feed the rampaging KTM 790 Duke a couple more gears, and 100 mph arrives in 6.49 seconds.
It storms through the quarter mile in a strong 11.01 seconds at 124 mph, a genuinely great time for this type of bike.
The popular 0-200 km/h benchmark is dispatched in 10.99 seconds.
The 790 comes very close to breaking into the 10-second bracket, which is impressive for a naked parallel-twin. In perfect conditions, it could easily dip under 11 seconds.
KTM 790 Duke Top Speed
Hold on long enough, and the 790 Duke will eventually reach 144.5 mph, although it takes around 40 seconds to get there.
With an efficient tuck, most riders should see a realistic 140 mph, arriving in roughly 20 seconds.
However, few people buy a naked bike like the 790 with flat-out top-speed runs in mind.
It is not what these machines are built for, and fighting the wind fully exposed can quickly become tiring.
From a performance perspective, the KTM 790 Duke is a true middleweight that can trade blows with some of the heavier hitters in the class above. It will be fascinating to see what the larger 890 brings to the table.
KTM 790 Duke Acceleration
| KTM 790 Duke Acceleration | |
| Speed | Time |
| 0-10 mph | 0.48 |
| 0-20 mph | 0.96 |
| 0-30 mph | 1.44 |
| 0-40 mph | 1.93 |
| 0-50 mph | 2.43 |
| 0-60 mph | 3.07 |
| 0-70 mph | 3.63 |
| 0-80 mph | 4.45 |
| 0-90 mph | 5,30 |
| 0-100 mph | 6.49 |
| 0-110 mph | 7.84 |
| 0-120 mph | 9.93 |
| 0-130 mph | 12.78 |
| 0-140 mph | 19.70 |
| SS/QM | 11.01/124 mph |
| SS/KM | 20.95/140.5 mph |
| SS/Mile | 30.41/143 mph |
| Top Speed | 144.5 mph |
