There's a whiff of dj vu about KTM's '08 LC4 launch, but for all the right reasons. A year after the 690 SM introduction, we were back in Spain to ride the 690 Duke, Enduro and SMC, all powered by the latest 654cc single with enough other changes to keep things interesting.
The 690 Duke gets a sharp new suit and more muscle underneath. It's the most powerful LC4, thanks to an airbox and exhaust system that bump peak output to an alleged 65 horsepower at 7500 rpm. Fly-by-wire injection fuels a riot of acceleration. Braking and cornering are equally fierce, and a vibe-canceling balance shaft means the Duke can be caned to an indicated 115 mph with minimal discomfort. The bolt-upright riding position is the big drag there. Better to make up some time in the bends, where the Duke's lightness, quick steering and capable suspension make for rapid, entertaining progress. The Duke can be thrown into turns with a tweak of that wide Magura handlebar with nothing on the deck but a boot toe and the sticky Dunlop Sportmax radials. Stopping is just as immediate. Brakes deliver instant bite, if not quite enough control, but that's the Duke: mad, bad and always entertaining.
The $8998 690 SMC comes with chassis bits similar to the 450 SMR racer. Aimed at the hard-
If the Duke is eccentric, the 690 SMC is certifiably insane. Essentially the same engine in a lighter chassis on longer-travel suspension and sticky street rubber, the SMC is similar to last year's 690 SM, but with significant differences. Developed from KTM's Rally racebike, the SMC's airbox is above its engine. A self-supporting plastic rear subframe holds the bike's 3.2 gallons of fuel and forms a base for the dual seat. A fully adjustable 48mm WP fork delivers 10.8 inches of travel, almost matched by the 10.4 inches of the WP shock out back. The SM has just 8.3 inches front and rear. The SMC's 17-inch wire-spoke wheels wear Pirelli Supercorsa Pro rubber. Its front brake is a Brembo blend: 320mm disc and four-pot, four-pad radial caliper like the Duke's, but no radial master cylinder.
Straight-line performance is akin to the Duke as well. An equally exposed riding position gives a similar feeling of speed well below the 120-mph maximum. It's still big fun to ride, but less practical than the Duke. That's partly due to a narrow seat that towers 35 inches above the dirt or tarmac. The tank underneath carries 3.2 gallons and puts gas stops about 125 miles apart.
This one really came into its own on the supermoto track, where its lightness, agility and grip made it stunningly fast and controllable though a selection of bends tight enough to stagger most other bikes. Ridden in boot-out supermoto style or knee down like a roadracer, the SMC charged around at a surprisingly rapid pace. It tips into turns with a tweak of those wide bars, punches out quite smartly and then stops on a dime, all with near-limitless cornering clearance. Experienced supermoto pilots will appreciate the slipper clutch, as well as the new engine's robust feel and balance-shaft smoothness.
On the downside, the SMC is too focused for most riders, especially since it's pricier than the standard 690 SM. But as a competitive, street-legal supermoto racer that's huge fun on track days or twisty roads, KTM's craziest single makes perfect sense.