KTM 790 Duke Motorcycle Review

KTM 790 Duke Review Page Three

A well-hidden radiator helps the engine keep its cool and is assisted by a thermo-fan. During hard riding on the launch the machines never got hot, but an extended burnout session by one of the Japanese journalists did see a machine display ‘hot engine temp’ on its comprehensive and well thought-out full-colour TFT display. I then jumped straight on that particular machine for a mono shot, and it took only a few hundred metres of cruising up and down the short strip to get the engine temperature back to normal before I hoiked it up on one for the photographer.

The 790 Duke is not actually all that much of a wheelie animal. The long die-cast open-lattice swingarm, smooth power delivery and the way the shock compresses via its direct mount system (rather than a linkage), all combine to make it a bit harder to sit up through a few gears than I had expected. The 790 Duke will never mono by accident. The long swingarm ensures it digs in and drives the front tyre forward rather than skyward. When going full berserk in the mountains I did get quite a few twitches and quick wiggles from the front, but the standard steering damper ensured they never got unruly. I get a feeling that without that damper the steep 24-degree steering head angle and 98 mm of trail might make for a ride that could get a little too lively.

The brakes are supplied by Spanish company J.Juan, a firm linked to race braking systems run by some Moto2 teams. KTM testers worked with J.Juan to back things off from the immediate precision and maximum braking efforts of racing hardware to achieve a compromise between feel, progression and power more tenable to street scenarios.

Both the 300mm four-piston radial fronts and the two-piston 240mm rear worked flawlessly for me. Only when getting in too hot a couple of times would I have liked a little more extreme power at the front in return for a little less effort at the lever, but I had cocked it up by then, so would any more braking power actually been all that more useful?

WP makes the non-adjustable 43mm inverted forks and gas-charged lay-down shock absorber that acts directly on the swingarm, rather than via a traditional bottom linkage. Adjustment is limited to preload, and only on the rear. On a machine that otherwise wows on the spec sheets, this has been a source of much keyboard warrior conjecture in the lead up to the release of the machine.

Somehow though, it just works. Testers ranged in weights from 60 kg to double that and there was very little criticism from any of us about the performance of the suspension. That long swingarm must play an important part in that equation as despite a pace that was truly barking mad, the damping never went away, the machine never wallowed and it just got on with doing the business. There was little to complain about up front either, as the open-cartridge forks with the compression circuit in one leg and rebound in the other, controlled the progressive fork springs quite deftly.

KTM actually started out using 48mm forks but in its quest for flex and feedback at street speeds (this is not a road-race bike after all), actually ended up opting for 43mm stanchions. The forks offer 140mm of travel, while the shock offers a fairly generous 150mm.

At the end of what was a day that saw these bikes tested to the absolute extreme outer level of street-riding performance in the mountains of the Canary Islands, it showed the overall competency of the package, clickers or not.

Ex Japanese Superbike hotshot, Hikaru Miyagi, goes all right… I spent much of the day with the massively experienced, and modest, Miyagi either on my tail, or leading me at a frightful pace through along the palisades of Gran Canaria, and at the end of the day he said when he got back to Japan he was going to order one.

That goes to show how much fun we had been having on those absolutely amazing roads. It also demonstrated just how well the machine performed; a bloke who has raced Superbikes at the highest levels in Japan, and even got to race a 500cc GP bike, thought it competent and enjoyable enough to be hauling Yen out of his own pocket.