Back-to-back test: Yamaha MT-03 vs KTM Duke 390 review

Back-to-back test: Yamaha MT-03 vs KTM Duke 390 review

The two most exciting sub-500cc nakeds on the market go head-to-head

WHAT’S Europe ever done for us? Well, it’s arguably the reason we have these two bikes, or at least the licence rules that create a place for them in the UK market.

That’s right – those meddling Eurocrats are indirectly responsible for probably the two most exciting sub-500cc naked bikes we’ve seen in decades.

I wrote once about the KTM RC390 that it was the closest thing we have today to two-strokes of the ‘80s and ‘90s, and some readers reacted like I’d defiled the memory of their first love.

I stand by it, and think the same is true of the 390 Duke, the original naked version of the RC390 using the same engine and chassis. Of course it’s very different – it’s a four-stroke single – but it makes 43.5hp and weighs 139kg dry, putting it near enough in RD350LC territory (47hp and 143kg according to

Basically, there’s nothing else on the market this small which goes this fast, with the possible exception of Yamaha's MT-03, the naked version of the R3.  

In fact even that can’t quite match the impishness of the KTM. The Yamaha seems tiny until you get back on it after trying the tinier Duke, which makes it feel like a middleweight.

The seat of the MT-03 is lower and the bars further away, so that you feel more that you’re sitting in it than on it. It’s like getting off a toy and onto a proper bike.

By any standard other than the KTM’s, the MT-03 is still very small, and slices through city traffic like a Hattori Hanzō sword, but with more poise and balance.

But again, it’s an impression which is put into a new perspective by the KTM, which is like the same blade heated by fire and used to part butter. If a bicycle can squeeze through a space, so can the Duke, usually.  It will turn sharply enough to cut 90° angles across unmoving queues and fire itself through closing gaps with a twitch of throttle, and it’s controllable enough to do it all without taking a foot off a peg.

Both machines are precision tools for commuting, rivalled in the city perhaps only by each other, but there’s a lot more to them than that.

At 42hp, the MT-03 is slightly down on power compared to the KTM and 5hp shy of the A2 licence limit, but it doesn’t feel lacking. The 321cc parallel-twin engine is useful everywhere in the range, with a reasonable spread of torque. It’s a machine you can thrash to the red line in almost every gear without fearing for your licence, but you don’t have to wring its neck to feel like you’re making progress on the motorway or country roads. It’s lively from about 5,000rpm in third, so you can drive briskly out of corners without being constantly on the limit, while its dimensions and weight (168kg with a full tank) mean it couldn’t be easier to sling it on its side for the next bend.

Will it surprise you now to hear that the KTM takes this sprightly nimbleness and again turns it up to 11?

The MT-03 may be lively but the Duke has something it doesn’t: punch. Real, surprising punch in a bike so small, enough to rock the Duke back and forth on its budget suspension components with a small wrist movement, and see it charging toward the horizon with unlikely enthusiasm.

What’s interesting about both these machines is that, faced with stifling restrictions – 47hp and no more than 0.27hp per kg – they manage to be really good fun.

By not going for the full 47hp, they’re able to be significantly smaller and lighter than the likes of Honda’s CBR500R. With a full tank the MT-03 is close to the limit, at 0.25hp/kg, so it must be really pushing it on reserve.

And the KTM in fact just cheats. Having said it's fun despite the restrictions, a close look at the specs reveals it doesn’t quite meet them. Its claimed dry weight gives it 0.31hp/kg. Hard to imagine that a manufacturer would produce a machine that misses out on a licence category by a couple of horses, but that’s KTM for you. It means the firm has to make a slightly less powerful version of the 390 Duke, with 40.8hp, for A2 licence holders. That still puts it over the A2 limit without fluids, at 02.9hp/kg.

This, and the KTM’s stronger peak torque, explain why it is able to easily leave the Yamaha behind in a roll-on acceleration test from 30mph in second gear. Often acceleration tests are close in back-to-back tests but this time there was no need for a re-run. The Duke decisively pulled away from the MT-03, although the rider needed to find a higher gear much sooner.

Where the MT-03 has a white shift light that doesn’t come on until about 11,500rpm, and a red line up at 12,500, the KTM has a red light that flashes on at 8,000. The engine doesn’t yet feel like it’s running out of power so you find yourself looking at that light quite a lot. It’s a bit annoying. The light's programmable, so you can set it to come on higher in the range, which is something I would do. 

There’s one really important respect in which the MT-03 is superior to the 390 Duke. It’s a better all-round motorcycle on a budget. Where the KTM’s suspension is basic but firm-ish, the Yamaha’s is basic but soft-ish, making it more comfortable for longer rides. It’s got a grab-rail and more space for a pillion. I gave our photographer a brief pillion ride on both machines. On the KTM I was crushed against the tank and his arse was sticking out over the end. There was definitely more space on the MT-03.

Neither machine has stunning brakes, although both will stop quickly with enough pressure on the lever. The level of power is about the same but there’s slightly more feel from the Yamaha’s single front disc, even though the KTM’s caliper is radial-mounted and has four pistons instead of two. It just goes to show that the trickest isn’t always the best.

The MT-03’s engine feels smoother and more fluid than the KTM’s, although the Duke’s is the better sounding of the two as well as the more potent.

The MT-03 is going to have a longer range, with its 14-litre tank compared to the Duke’s 11. Calculated from fuel receipts, we got 57.6mpg from the Duke on the road test and 61.2mpg from the MT-03. That gives a theoretical range of 139 miles from the KTM and 190 from the Yamaha.

The 390 Duke seem to run hotter than the MT-03 in town, with its fan almost perpetually on. 

And the Yamaha has easily enough space under the pillion seat for a disc lock, while getting the KTM’s seat to close over my Abus lock required guile and cunning.

The MT-03 is a more practical machine.

But the KTM is something else, something better than practical. It’s special, like a 125 with a proper engine fitted. I say ‘like’ but that is in fact what it is, since it shares its steel trellis frame with the Duke 125.

I remember in the late ‘80s, Performance Bikes (Performing Berks) magazine set about trying to fit a KX250 engine into an AR125. They never quite managed to make it work but it was an exciting idea to a 17-year-old me, and I bought the magazine every month hoping for an update.

The 390 Duke reminds me of it, with its 373cc single in the chassis of a 125, but it’s better, and it works, and someone has put it into production and you can buy it. Who cares how practical it is?

The fact KTM has been silly enough to make it a couple of hp too powerful for A2 is telling. The 390 Duke isn’t really a bike made to match a licence category. It’s a bike made just because.

I rode both bikes home and it was the KTM that I noticed the young scooter louts from the estate looking at, not the Yamaha with its conservative black paint. I made sure my garage was locked that night.

The KTM is a bike that you want in your garage not because of any licence restriction but just because you want it in your garage. That’s why, as impressive, useful and fun as the MT-03 is, it can’t possibly win this test.

Read our back-to-back test of the KTM RC390 and Yamaha YZF-R3 here and watch the video review here.


Model tested: KTM 390 Duke

Price: £4,549 plus on-the-road charges

Engine: 373.2cc single

Power: 43.5hp

Torque: 25.8lbft

Weight (dry): 139kg

Frame: steel trellis

Suspension: preload adjustable shock and 43mm (outside tube) non-adjustable upside-down fork, both from WP

Brakes: single 300mm front disc with four-piston radial caliper, single piston rear caliper, Bosch ABS as standard.

Tyres: Metzeler Sportec 150/60-17 rear, 110/70-17 front

Seat height: 800mm

Fuel capacity: 11 litres

Fuel economy on test: 57.6mpg

Colours: black/orange, white/orange

Availability: now

Model tested: Yamaha MT-03

Price: £4,499 plus tax and registration

Engine: 321cc parallel-twin, DOHC four-valve

Power: 42hp @10,750rpm

Torque: 21.8lbft @ 9,000rpm

Weight (wet, with full tank): 168kg

Frame: diamond-type steel

Suspension: preload adjustable shock and 41mm non-adjustable right-way-up fork, both KYB

Brakes: single 298mm floating front disc and twin-pot caliper, 220mm rear disc with single-pot caliper. ABS standard.

Tyres: Michelin Pilot Street 140/70-17 rear, 110/70-17 front

Seat height: 780mm

Fuel capacity: 14 litres

Fuel economy on test: 61.2mpg

Colours: silver/blue (Race Blu) or black (Midnight Black)

Availability: now