Although a small niche in the motorcycle market, big-bore, single-cylinder supermotos like the Husqvarna SMS630 dice up urban congestion with surgical precision. We should expect that kind of accuracy from Husky; after all, the currently BMW-owned outfit got its start manufacturing military rifles in the late 17th century.
Husqvarna also knows a thing or two about supermoto, having won 13 world titles in that discipline. Origins for the SMS630 can be traced back to the 1999 SM 610, which was the only production supermoto bike sold in the U.S. at the time. This 2011 model benefits from the most comprehensive redesign to date.
An all-new 600cc engine (the 610’s actual displacement was just 576cc) features a bore increase from 98 to 100mm, with stroke standing pat at 76.4mm. Its four valves are now tickled by twin cams in place of the previous single unit. The updated fuel-injection system has a 45mm Mikuni throttle body, while the exhaust system incorporates a closed-loop lambda O2 sensor, a catalyzer and twin aluminum silencers.
So, how does the SMS compare to the class-leading KTM 690 SMC (Roundup, December, '10)? Well, for starters, the Husky's nearly 36-inch seat height is taller than the KTM's, making the reach to the ground a stretch for anyone with a short inseam. But at least the seat is cushy enough that, combined with the plushness of the 45mm Marzocchi fork and fully adjustable Sachs shock, it blesses the SMS with a more luxurious feel than the harder-edged, more stiffly sprung KTM.
I rode the SMS everywhere, from urban streets to mountain curves, and the 630 carved up everything I threw at it. Sticky 120/70 and 150/60 rubber wrapped around wire-spoked 17-inch rims provides grip at nearly any angle of lean. Weighing just 320 pounds dry on the certified CW scales, the Husky feels very light and agile compared with a typical sportbike. In tight corners, the 630 snaps into a deep lean with little effort. The chassis was also very composed on rain-grooved Southern California freeways and never showed any instability or tendency to weave, which is a common criticism in this class of machines.
Power output is 46 hp and 35 foot-pounds of torque (measured on the CW dyno), and acceleration is good. Fueling, however, was sporadic, with an inconsistent idle occasionally causing the bike to stall at stoplights. Our testbike's engine also hunted a bit at a steady rpm. It's not a deal-breaker, but the mapping would benefit from refinement. Around town, engine vibration is barely noticeable; on the freeway with the engine spinning above 5000 rpm, vibes are prevalent through the handebar and frame.
So, while it isn't a match for the racier, more-aggressive (and $1300 more-expensive) KTM 690 SMC, the $8999 SMS630 provides a plusher, less hardcore and, arguably, more enjoyable overall riding experience. Ultimately, Husqvarna has paid tribute to its supermoto heritage while still keeping its competition in the crosshairs.