KTM 390 Duke (2024) - Review

Technical Review: Ben Purvis
Riding Review: Adam ‘Chad’ Child

Price: £5699 | Power: 44.3bhp | Weight: 154kg | Overall BikeSocial Rating: TBC 4/5

“No bullshit.” That’s KTM’s calling card for new range of single-cylinder naked models led by the all-new 390 Duke – a machine that retains its predecessor’s name but carries over little else from the model that came before.

The original 390 Duke hit the market more than a decade ago as part of KTM’s 2013 range, and was already a familiar face even then, essentially being an enlarged version of the 125 Duke that had arrived in 2011. In the intervening decade there have been tweaks, notably a new headlight for 2017, but most of the bike’s specs have remained unaltered. That changes for the 2024 model year with a completely new chassis, a heavily revised and enlarged engine. Like most model updates the targets are more power and less weight, and KTM appears to have hit both.

Throw in new looks, debuting the latest iteration of KTM’s family ‘face’, and uprated, adjustable suspension and the 390 Duke makes a compelling case for itself as a steppingstone between L-plates and bigger bikes.

KTM says that 90% of the bike is new, meaning very little of the old bike remains. We headed to southern Spain for a crazy ride out, and some fun gymkhana to see if the new KTM 390 can live up to KTM's ethos of ‘Ready to Race’.

KTM 390 Duke (2024) review by Adam 'Chad' Child from the press launch near Almeria in Spain. This all-new single-cylinder, A2 licence-compatiblemotorcycle from the chirpy Austrian marque full of youthful exuberance.

2024 KTM 390 Duke Price

The 390 Duke's price has been confirmed at £5699, which places it slightly below the competition, despite its raft of new technology and high-end finish. We can assume some of this cost saving is because the bikes are produced in India, not Austria like the larger 990 and 1390. PCP prices are even more attractive: with a £1000 deposit, monthly payments are £79, only £10 per month more than the learner legal 125 Duke. That's a lot of bike for the money considering the 390's high-level specification for this entry-level A2 licence category.

2024 KTM 390 Duke Engine & Performance

Even from the outside, the new 390 Duke engine looks notably different to the previous model, with new castings for the cases and cylinder, as well as a more compact cylinder head design. Inside, it’s bigger than before, with a capacity hike from 373cc to 399cc courtesy of a longer, 64mm stroke, up from 60mm, while the bore remains unchanged at 89mm.

The extra size adds a little power – up from 43hp for the old 373cc version to 45hp for the 399cc bike – but more importantly it brings that peak down from 9,500rpm to 8,500rpm. That points to a bigger boost in torque of 28.8 lb-ft at 7,000rpm, up from 25.8 lb-ft at 7,250rpm before.

The new engine, which also forms the basis for the new 125 and 250 Duke models, is dubbed LC4c. The ‘LC4’ bit is familiar KTM terminology – standing for Liquid Cooled, 4-valve – while the lower case ‘c’ at the end mirrors that of the 889cc LC8c used in the 890 Duke and Adventure models, standing for ‘compact’.

KTM could have easily given us significantly more power but, to keep the bike A2 licence compliant they are limited it to 35kW. The 390 Duke is already close to the limit (33kw), which is why by increasing capacity they have increased torque and moved peak power and peak torque lower in the rpm. In theory this makes the new it less peaky meaning you shouldn’t have to be clicking up through the gears (via a neat quick-shifter, I hasten to add) to make rapid progress.

Without a back-to-back test against the old bike, it’s impossible to quantify how much progress KTM has made, but the new 390 certainly feels punchy for an A2-compliant bike. You can rattle along at a brisk pace without having to bounce the free-revving single off its rev limiter. Its rather wide sweet spot sits between 4000rpm and 8000rpm, where the midrange drive is strong and satisfying, the engine responsive and urgent. Cruising at 120kph (75mph) is surprisingly relaxed, too, while around town, at far lower revs, it's smooth for a single, though the fuelling is a tad sharp going from a closed to 20%-open throttle.

There are three riding modes to choose from:  Track, Sport and Rain. They can be selected on the move and are clearly displayed by a new 5-inch TFT dash. Track mode changes the dash's layout, giving a sportier, rev-counter-focused race display and sharpens the throttle response too. This is a little abrupt on the road, especially around town, and I spent 90% of the test in the smoother Sport mode, with the traction control off. Even at a gymkhana race KTM had prepared for us, I still preferred the Sports mode.

The optional up-and-down quick-shifter was fitted to our test bike and although it was fun running through the gearbox in chase of very last horsepower, it wasn’t perfectly slick and threw in the odd missed gear or clunky shift.

2024 KTM 390 Duke Handling & Suspension (inc. Weight & Brakes)

Like the engine, the frame is entirely new, although if you’ve been paying attention, it might look a little familiar – the Husqvarna E-Pilen electric bike prototype, which was wheeled out in public back in 2021, used exactly the same design. That makes sense, as KTM is also known to have been working on an electric Duke based on the same structure, and if both battery-powered and ICE models can share common components it hugely reduces up-front costs for manufacturers.

The frame itself is a steel trellis of the sort we’re used to seeing from KTM, but it’s a rather slimmer and more elegant design than the one used on the original 390 Duke. At the back, the old bike’s steel subframe is replaced with a cast aluminium design, and despite looking more delicate that its predecessor, the new chassis is claimed to have better torsional rigidity, improving rider feedback.

Despite the new chassis, styling and engine, the 2024 390 Duke’s wet weight, including a full tank of fuel, is unchanged from its predecessor, already impressively light at a claimed 154kg.

At the back, a banana-style swingarm arches over the underbelly exhaust – something that was also a feature of the original 390 Duke but was lost as that bike was updated to meet changing emission laws. The swingarm’s curve serves a double purpose, not only clearing the tailpipe but also providing a lower mount for the single, offset rear shock.

As we expect from KTM, all the suspension is from its WP subsidiary, with 43mm APEX forks and a matching APEX shock. Unlike its predecessor, the 2024 390 Duke has adjustable suspension, tweakable for both rebound and compression at the front, and for rebound and preload at the rear.

The brakes, like the old model, feature a single, radial-mount four-pot caliper at the front, from Brembo subsidiary ByBre, grabbing a very slim 320mm disc. At the rear there’s a two-pot caliper and 240mm disk. Unusually for a bike in this part of the market, there’s lean-sensitive, cornering ABS as standard. It’s KTM’s ‘Supermoto ABS’ system, which allows the rear wheel’s anti-lock to be switched off while keeping it active on the front.

The presence of lean-sensors means KTM has also been able to include cornering traction control, and there’s even a launch control system as standard.

Who would have guessed 15 years ago, when the first electronic rider aids came to the market on flagship superbikes, that before too long entry-level, A2-compliant street bikes would be festooned with digital technology too? The new KTM 390 Duke comes with lean-sensitive rider aids, traction control and ABS, plus launch control and a pit-lane limiter, not forgetting that optional quick-shifter. All that technology on a bike with only 44.3bhp (33kw) might seem like overkill but such are the demands of the modern market that anything less was unthinkable to KTM.

The pit lane limiter is more likely to be used around town to keep the 390 Duke within strict 20mph and 30mph limits than at Donington Park, and the launch control will mainly be used for impressing mates. But the lean-sensitive TC and ABS are real plus points for newer riders. For the more experienced, the rider aids can be turned off (a Supermoto ABS setting allows you to lock the rear, but still have ABS on the front) because KTM wanted the Duke to be both fun and safe – which it is.

The ByBre single front brake caliper and 320mm disc are similar to the previous model's but are now on the right side. This is simply for styling as the single discs and new WP rear shock are both on the right side. Despite the on-paper similarities between the old and new, the new stoppers feel improved. This might be down to the feel from the new forks, reduced un-sprung weight (more below), or the overall lightness of the bike – but they are sharper and stronger on the 2024 machine. Meanwhile, the lean-sensitive ABS isn’t too intrusive and works like a huge safety net for new riders.

As mentioned, KTM is claiming a huge reduction in un-sprung weight, with new wheels a staggering 4.3kg lighter than the old model's! Topping the scales at 165kg overall (that's a wet weight, by the way), the 390 feels incredibly light all-round. It turns on proverbial sixpence and nonchalantly shrugged off the low-speed agility challenge of the gymkhana course. At slow speeds, the subtlest of rider inputs get the Duke cranked over. In fact, it’s so small and light it can feel like a toy at times but this doesn’t translate to instability because, at high speeds, the 390 is predictable and unfazed.

We did get a short opportunity to test the handing in the hills around Malaga in southern Spain and the WP suspension setup is impressive for this type of bike. The APEX forks have feel and control and perform well above the bike's sub-£6000 price tag. Unlike the older model, their compression and rebound damping settings can be tweaked, with each single click equal to five clicks on racier, more sophisticated WP suspension. So, while you have fewer clicks to play with, you gain simplicity.

At the rear is a completely new side-mounted directly mounted WP APEX shock, with easy access to pre-load and rebound adjusters. I’d suggest I’m slightly heavier than the target 390 owner, but it coped with my weight and aggressive riding. The ride is comfortable but, without any linkage, it did feel a little firm at the bottom of the stroke, something exacerbated by a relatively thin seat.

The suspension is complimented by Michelin Power 6 rubber and helps deliver a handling package that is impressive for a bike in this category. The steering is light, the turn quick and accurate; it's stable at speed, agile around town and invites knee-down confidence for the more experienced. Fit some track day rubber and the 390 Duke is indeed ready to race. And for those in the real world, those lean sensitive rider aids will be just as useful as you dart through traffic running late for work.  

2024 KTM 390 Duke Comfort & Economy

KTM’s optional extras also include an array of protective elements including crash bars, which might be handy for inexperienced buyers.

As you’d expect, the 390 is frugal. KTM claims 3.4l/100km, which equates to 80mpg. After 128km (80 miles) of immature riding, I’d averaged 4.8l/100km or 59mpg, which is excellent considering the throttle was wide open for much of the time. With a 15l fuel tank, that equates to around 190 to 250 miles between fuel-ups. For those commuting, that’s probably just one tank of unleaded a week or less.

However, despite the frugal engine and over 200 miles between filling up, I won’t be volunteering for a touring trip on the 390. KTM has tried to make the 390 as accessible as possible, and the seat is even lower, down by 10mm to 820mm, but comfortable it isn’t. I’m only 5ft 7ins so wasn’t too cramped but taller and heavier riders suffered as the seat is firm and the direct-mounted WP suspension lacks plushness over big bumps. I was starting to move around in the saddle after a reasonably long ride but not as much as the bigger lads who looked unhappy after two hours in the saddle. The bar reach isn’t bad and the ergonomics work for shorter riders, but if I were to take on some serious miles, I’d want a comfier seat.

2024 KTM 390 Duke Equipment

The existing 390 Duke was already among the early adopters for the now-ubiquitous colour TFT screen instead of old-school analogue instruments, and the new model continues that trend and adds to it.

The screen is now a five-inch TFT, with a bonded glass screen for a clean appearance, and gives access to uprated tech including a trio of riding modes – Street, Rain and Track – each altering the bike’s responses. As usual, ‘Rain’ softens throttle response and ratchets up the traction control sensitivity, while ‘Track’ switches the TFT screen to a different layout, emphasising the rev counter and adding a lap timer and gear display as well as the traction control and ABS settings.

There’s turn-by-turn navigation, call answering and music control, too, if you link your phone and install the KTMconnect app.

Elsewhere, the 390 Duke gets new, illuminated bar controls and full LED lighting , as well as standard launch control. Delve into the options list and you can add KTM’s Quickshifter+ up-and-down quickshift, and there will also be a range of bolt on options including a Remus exhaust.

Unlike some larger bikes in KTM’s range, there isn't a ‘Demo’ mode, which allows you to try different rider aids and tech, then pay an extra amount after 1500km (930 miles) should you want to keep them. What you see is what you get with the 390, though I can see most potential buyers opting for the quick-shifter straight away.

It's interesting and something of a challenge to see where KTM has saved costs to keep the price competitive and below the Yamaha MT-03 and Kawasaki Z400. Yes, it’s only a single cylinder but the 5-inch dash with connectively will appeal to the iPhone generation. Lean sensitive rider aids, adjustable WP suspension, quality Michelin rubber... Where have they cut corners?

The switchgear is unremarkable but works well enough, and you could argue the 390 lacks the build solidity and mechanical resonance of the other bikes in this class. Its lightness, though, is key to the 390 Duke's performance and ride as well as being one of KTM's signature dishes across all its bikes.

2024 KTM 390 Duke Rivals

There are plenty of alternatives on the market to make KTM’s life tougher, including both single-cylinder and twin-cylinder alternatives. Yamaha’s MT-03 is perhaps the most obvious one, but in the near future we’re expecting KTM’s Chinese partner company, CFMoto, to bring its new 450NK twin to the UK market, with around 50hp on tap, and don’t ignore Kawasaki’s Z400 and BMW’s G310R, either.

Yamaha MT-03 | Price: £6,005

Power/Torque: 41.4bhp/21.8lb-ft | Weight: 168kg

Kawasaki Z400 | Price: £5,799

Power/Torque: 44.8bhp/27.3lb-ft | Weight: 167kg

BMW G310R | Price: £5,190

Power/Torque: 33.5bhp/20.7lb-ft | Weight: 164kg

2024 KTM 390 Duke Verdict

KTM has produced a 90% new 390 Duke which should have the competition worried. It comes with lean-sensitive rider aids, riding modes, launch control, a pit lane limiter, adjustable and quality WP suspension and decent rubber. With a 5-inch TFT dash with connectivity and bold looks it should have a young A2 audience hurrying to their local KTM dealer.

We only got a flavour of the bike on test.  It's ability over a longer ride and how it fares against the twin-cylinder competition remain unknown but on this brief test it looks like KTM has upped their game significantly with the new 390 Duke.

It is lightweight, small, easy to ride; a fun machine backed up by useful rider aids. The gearbox and quick-shifter aren't perfect and, for some taller riders, the 390's lack of comfort may be off putting. For the young audience KTM is aiming at, however, I can see it being a ready-to-race, 'no bullsh*t' hit.

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2024 KTM 390 Duke - Technical Specification

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