2025 KTM 125 & 390 SMC R - Technical Review

KTM might have made inroads into most corners of the motorcycling world but the company’s name remains inextricably linked with single-cylinder off-roaders supermotos – so the new 125 and 390 SMC R models that join the lineup for 2025 are aimed directly at the heart of its customer base and provide a much-needed expansion of the brand’s supermoto range.

And the Austrian company needs some hits at the moment. KTM may be Europe’s biggest motorcycle maker, but ill-timed expansion just as the market contracted means it’s spent the end of 2024 and start of 2025 under self-administration, sorting out a new deal for creditors to secure the brand’s future. New offerings targeting its core customers, like the new SMC R machines, should help.

Pros & Cons

2025 KTM 125 SMC R & 390 SMC R - Prices & PCP

Small supermotos are pretty thin on the ground on the new bike market in 2025 – particularly from brands as well-known as KTM – so it’s not straightforward to judge whether the 390 SMC R at £5699 and 125 SMC R at £4899 are attractively-priced. But in terms of comparing them with street bikes of similar performance, they’re in the right ballpark.

In fact, the prices are identical to the costs of the existing 125 Duke and 390 Duke, bikes that share their engines and the essence of their chassis with the new KTM SMC R models.

The smaller bike might be the harder sell as it’s up against some rival learner-legal supermotos, albeit often from less well-known brands, at a lower price. Of those, Aprilia’s SX 125 is probably the most familiar, with a list price of just £3780, while you can get your hands on a Sinnis SM-R 125 for as little as £3299.

Both the new models are due in KTM dealers from March 2025.

2025 KTM 125 SMC R & 390 SMC R - Engine & Performance

Both the new SMC R models borrow their powerplants from the latest small Duke models, and while the 125cc and the 399cc ‘390’ motors are rooted in a shared design – dubbed LC4c – there are substantial differences beyond the obvious chasm between their capacities.

As you’d expect, the 125 SMC R is aimed squarely at L-plate riders, and as such its power peaks at 15hp – the legal limit for learners – which is reached at 10,000rpm. That’s paired to 8.5lbft of torque, achieved at 7750rpm. With no requirement to maximise the possible output of the engine, it’s designed with a single-cam cylinder head, keeping costs down.

The 390 version, in contrast, is operating in without a legislation-imposed limit on its power, so KTM has given it a higher state of tune. The differences include not only the increased capacity, via an 89mm bore and 64mm stroke (58 x 47.3mm for the 125), but a DOHC cylinder head. The result is a peak of 45hp at 8500rpm and 28.8lbft at 7000rpm.

The latest LC4c engine is substantially different from the earlier single-cylinder KTMs, with more capacity for the 390 (previously 373cc with a shorter 60mm stroke) and a design that’s developed to meet the latest Euro5+ emissions rules despite an exhaust that packs two catalytic converters and a silencer into the space under the engine, so there’s no side-mounted end can. There’s also new fuel injection, with injectors that provide a finer spray and point at the inlet valves to help clean them of carbon build-up, and a new airbox that’s designed to allow the engine to sit higher in the chassis, boosting ground clearance.

The engine drives via a new six-speed transmission that promises reduced shifting forces compared to the earlier design, via a slip/assist clutch. A quickshifter is optional.

2025 KTM 125 SMC R & 390 SMC R - Handling & Suspension (inc. Weight)

The chassis shared by the two new SMC R models borrows the basics of its design from the latest 125 Duke and 390 Duke but with substantial changes to suit the SMC Rs model’s different stance and intentions.

The head angle, yokes, subframe and rigidity are all tweaked to give a more off-road-style setup, and the cast aluminium swingarm is a new design that’s expected to be shared with the soon-to-be-revealed 2025 125 and 390 Adventure models.

Both the 125 and 390 SMC R use KTM’s usual WP suspension, with 43mm USD APEX forks and a matching offset monoshock at the back, each end offering 230mm of travel. On the pricier, higher-performance 390 model, the forks are adjustable for compression and rebound, while the rear is rebound and preload adjustable. The 125 makes do with rear preload adjustment only.

Both bikes use 17-inch wheels at both ends, with a 110/70 front and 150/60 rubber at the rear, but the 390 benefits from wire wheels while the 125 uses cast alloys. And regardless which model you choose, you get the same 320mm front brake disc and 240mm rear, with ByBre calipers.

Those stoppers should be well up to the job of hauling down the speed on such lightweight machines, with the 125cc version coming in at a mere 145kg wet, while the 390 is only 9kg more at 154kg.

2025 KTM 125 SMC R & 390 SMC R - Comfort & Economy

If you’re concerned about comfort, you’re probably not part of the target audience for a supermoto – it’s not a niche that’s known for cossetting riders in the lap of luxury – but in some respects the wide bars, slim seat and low-set pegs are a practical proposition.

The upright riding position and wide bars mean you’re inevitably going to be exposed to the brunt of the windblast, but at least you’re not going to be crunched into a backbreaking posture.

With its roots in offroad design, the SMC R’s rider triangle is intended to make it practical to stand on the pegs as well as riding in a seated position, and the company points out that the 9-litre fuel tank is particularly slim, helping with the ergonomics and keeping it safe from damage if you drop the bike. The subframe is also designed with crashes in mind, being bolt-on so it’s easy to replace if damaged.

At 860mm the seat is fairly high – a natural corollary of the supermoto layout – but it’s still 30mm lower than the new Suzuki DR-Z400SM.

Fuel economy isn’t likely to be a big concern to customers, but it’s actually pretty impressive. The 125cc version is rated at a strong 117mpg, allowing the potential for a range of 233 miles from a full tank, while the 390 is good for 83mpg, making for up to 164 miles of range.

2025 KTM 125 SMC R & 390 SMC R - Equipment

You wouldn’t expect a supermoto to come with a huge array of luxuries as standard and the KTM SMC R models don’t buck that trend – they have what you need, but little more.

The 390 is the better-equipped bike, with selectable riding modes – Street or Sport are the options – with traction control and ABS settings that get tweaked to suit. That traction control can also be switched off entirely, if you prefer. In Sport mode, the ABS can be switched between three settings: Road, Supermoto or Supermoto+. The 125 version does without riding modes, though.

Both bikes get LED lighting throughout, plus a new 4.2-inch TFT dashboard with a bonded glass screen that’s claimed to improve its readability under bright sunshine, as well as phone connectivity via the KTM Connect app, giving control over music, calls and turn-by-turn navigation though newly-designed switch blocks on the bars.

2025 KTM 125 SMC R & 390 SMC R - Rivals

The supermoto market isn’t as well supported as it was a couple of decades ago but could be seeing something of a renaissance in 2025 with the introduction of the new Suzuki DR-Z400SM as a new mainstream offering. That bike will surely be the clearest competitor for KTM’s 390 SMC R, at least until the inevitable GasGas and Husqvarna spin-off versions of the Austrian bike are launched.

The 125 SMC R has a tougher market to face, with rivals from the likes of the Aprilia SX 125, Sinnis SM-R, and, at the higher end of the price range, the Fantic XMF 125.

Suzuki DR-Z4SM | Price: £TBC

Read more

Power/Torque

37.5bhp / 27.3lb-ft

Weight

154kg

Aprilia SX125 | Price: £3780

Read more

Power/Torque

15bhp / 8.4lb-ft

Weight

136kg

Fantic XMF 125 | Price: £5199

Read more

Power/Torque

15bhp / 8.7lb-ft

Weight

112kg

2025 KTM 125 SMC R & 390 SMC R - Verdict

We’ll give a verdict once we’ve ridden the bikes!

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2025 KTM 125 SMC R & 390 SMC R - Technical Specification

What is MCIA Secured?

MCIA Secured gives bike buyers the chance to see just how much work a manufacturer has put into making their new investment as resistant to theft as possible.

As we all know, the more security you use, the less chance there is of your bike being stolen. In fact, based on research by Bennetts, using a disc lock makes your machine three times less likely to be stolen, while heavy duty kit can make it less likely to be stolen than a car. For reviews of the best security products, click here.

MCIA Secured gives motorcycles a rating out of five stars (three stars for bikes of 125cc or less), based on the following being fitted to a new bike as standard:

• A steering lock that meets the UNECE 62 standard

• An ignition immobiliser system

• A vehicle marking system

• An alarm system

• A vehicle tracking system with subscription

The higher the star rating, the better the security, so always ask your dealer what rating your bike has and compare it to other machines on your shortlist.