The 2017 Duke 390 is powered by the same 373cc water cooled single cylinder engine. Although power figure of 43bhp is the same, torque has gone up by 2Nm and it comes about 250rpm sooner too. To meet the stringent Euro 4 norms, KTM has made changes for the new bike to breathe better. As a result you get a bigger air box, a bigger catalytic converter, revised exhaust, different fuel mapping and ride by wire throttle body.
All this results in a bike that feels distinctly different right from the time you start it. Thumb the starter button and the new Duke 390 settles into a refined idle with very few vibrations creeping through. You also get a more linear response on throttle inputs at low speeds, which makes the new bike fare much better in stop go traffic. The engine also pulls better from lower engine speeds but still it doesn’t feel the happiest below 4000rpm in higher gears. Once past 5000rpm, the strong midrange and the enthusiastic upper reaches of the power band makes this bike as much fun as the old bike. Refinement has taken a huge leap forward, with vibrations well damped except for the foot pegs which transmit the most especially past 5000rpm. One of the biggest complaints, heating issues, has been addressed too. Sure it still gets relatively hot, but not as much as before and we rarely saw the temperature gauge pass the halfway mark. On the downside, the radiator fan is extremely noisy and cuts in much earlier than the old bike.
Complementing the refined engine is the more pliant ride. Where the old bike use to feel harsh and hard edged all the time, KTM has struck a good balance and the new bike feels easily a couple of notches better damped. The new WP upside down front forks that use an open cartridge design instead of piston help here. The rear shock too is different, as internally the oil and gas now sit separately, which leads to less heat and more consistent performance. The 2017 Duke not only feels suppler, it also has a flatter ride especially at the rear, where over undulating surfaces the old bike use to bounce a lot more before settling back down.
If you feel the Duke has gone soft and the higher kerb weight will make it less fun, you would be so wrong. The revised geometry and shorter wheelbase results in a bike that feels nimble and is more willing to drop into corners. What helps further, is the smoother on-off throttle transition, which gives you more confidence, while opening the throttle mid corner. Where the old bike has an edge though is in terms of mid corner stability, the new bike feels a bit twitchy in that respect. The tyres too are a harder compound as compared to the W rated Metzellers of old, and has much lesser grip, with more movement. But that is something you get used to and in the long run you will also appreciate the longevity of the H rated rubbers and its lower asking price as compared to the W rated ones.
Even braking is much improved. You now get a massive 320mm rotor and ByBre callipers that house sintered pads for better braking. KTM has also revised the master cylinder in pursuit of better feel and sharper bite. As a result the 2017 Duke 390 doesn’t suffer the same problems like the soggy feel and fade of the old bike which just adds to the rider’s confidence.