Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/1183666
K TM 890 DUKE R RIDE REVIEW P82 bigger-cubed motor by 500 rpm to 10,500 revs, while at the same time reducing the dry weight of the complete motorcycle by 7.3 pounds to 366 pounds, says Sinke—a savings mainly obtained by swapping to Brembo brakes from the J.Juans on the 790. For despite increasing the twin front discs diameter from 300mm on the 790 Duke to 320mm on the 890, the new package is 2.6 pounds lighter all told, thanks mainly to using aluminum carriers for the discs, and Brembo's new-gen Stylema radial one-piece calipers, which are both good-looking and also lighter than the J.Juan units. Switchable Bosch 2-channel ABS is fitted as standard for Euro-4 compliance. More power and torque yet with reduced weight (and largely unsprung at that, which has a benefi- cial effect on the now fully adjustable WP suspen- overall. This carries forged pistons, via a sophisti- cated cracked conrod design, which results in low piston weight and reduced reciprocating mass. The crankpins are offset by 75º (versus the more common 180º or 270º crank throws) with 435º fir- ing intervals to replicate the gritty sound of a KTM V-twin's irregular firing order. That heavier crank is to deliver a sense of momentum as the engine spins up, says Sinke, as well as greater stability in turns thanks to the gyroscopic function of the engine. This, in turn, has necessitated redesigning the twin counterbalancers—one at the front of the engine and one in the cylinder head—between the cam- shafts to eliminate vibration. The compression ratio has been raised from 12.7:1 to 13.5:1, thanks to a knock sensor now added to obviate detonation, and this, in turn, helps deliver improved acceleration. (Right) The 890 Duke R is powered by KTM's first- ever parallel-twin motor with 75º crank bored and stroked for 90cc more capacity than than the 790 Duke which was introduced two years ago. (Left) Switchable Bosch 2-channel ABS is fitted as standard for Euro-4 compliance, with a light-sensitive full color TFT dash. sion—the 790 Duke's was non-adjustable beyond rear spring preload) sounds like motorcycle R&D nirvana. After being honored to be chosen as the first person outside the company and its suppliers to ride the new bike in pre-production prototype form, it took about six miles of the 110- plus miles I covered on a hard-ridden tour of the Salzkammergut mountains in KTM's back yard, to realize how special this new KTM hotrod really is. Another of the many apparent paradoxes on what is a remarkable new motorcycle by any standards is that KTM has achieved this weight-saving while actually increasing the rotational mass of the forged one-piece three-bearing crankshaft by 20 percernt, which, of course, makes it heavier