KTM 660 SMC [2005-2006]: The Unapologetic Supermoto That Still Thrills

Introduction

The KTM 660 SMC stands as a raw, unfiltered love letter to supermoto enthusiasts. Produced between 2005 and 2006, this Austrian beast combines enduro toughness with street-smart agility in a package that feels more like a rebellious experiment than a mass-produced motorcycle. With its liquid-cooled 654cc thumper and race-bred chassis, the 660 SMC doesn’t just ride – it demands participation. This isn’t a bike for the faint-hearted; it’s for riders who crave visceral feedback and mechanical honesty in an era increasingly dominated by electronic nannies.

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Design & Ergonomics: Function Over Fluff

The 660 SMC’s design ethos screams “minimalism with purpose.” Its chromium-molybdenum steel frame, painted in KTM’s signature orange, wraps around the engine like exoskeletal armor. The 910mm (35.8") seat height towers over most street bikes, putting riders in a commanding position that’s equal parts intimidating and exhilarating. This isn’t a bike that apologizes for its proportions – it dares you to climb aboard.

WP suspension components dominate the layout. Up front, massive 48mm USD forks (the motorcycle equivalent of tree trunks) provide 300mm (11.8") of travel, while the rear monoshock offers 335mm (13.2") of wheel movement. These numbers belong on a dirt bike, yet here they are, paired with 17" cast wheels shod in sticky 120/70 front and 160/60 rear tires (note: specs vary slightly between sources – some list 169/60 rear). The result? A visual contradiction that somehow works – part motocrosser, part streetfighter.

The cockpit is Spartan but purposeful. A slim digital dash provides basic info, while wide Renthal-style bars give leverage for aggressive maneuvers. At 138kg dry (304 lbs), it feels shockingly light when pushing off the sidestand – a testament to KTM’s obsession with mass centralization.

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Performance: Carbureted Fury

Fire up the 654cc single, and the world narrows to vibrations beneath you and the metallic bark from the aluminum dual silencers. The Mikuni BST40 carburetor (some sources mention Keihin FCR41 – regional variations likely) delivers fuel with old-school abruptness. There’s no ride-by-wire smoothness here – just an immediate throttle response that keeps you constantly engaged.

Peak power arrives at 6,250 RPM – 28.2 HP (21 kW) that feels exponentially more thrilling thanks to the single-cylinder’s torque shove. That 42.5 Nm (31.3 lb-ft) torque figure hits at just 3,250 RPM, translating to wheel-lofting capability from idle. The engine’s character is Jekyll-and-Hyde: tractable enough for city commuting below 4,000 RPM, yet ferocious when wrung out. Liquid cooling (a rarity for big singles at the time) lets you punish it in traffic without fear of overheating.

The 5-speed transmission slots through gears with deliberate mechanical clicks. You’ll hunt for a sixth gear on highways, but that’s missing the point – this is a bike that lives for 0-100 km/h (0-62 mph) bursts and tight corners. Top speed? Around 160 km/h (100 mph), but you’ll feel every vibration at triple-digit speeds.

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Handling: Ballet on 17s

Where the 660 SMC truly shines is in its ability to transform urban landscapes into personal playgrounds. The combination of long suspension travel and supermoto geometry (27° rake, 99mm/3.9" trail) creates handling that’s both stable at lean and flickable mid-corner. Transitioning between turns feels like guiding a scalpel – minimal input yields maximum direction change.

Brembo anchors provide stopping power that borders on comical. The 320mm front disc (paired with a 4-piston caliper) could probably halt continental drift. Yet modulation remains superb – you can trail-brake deep into corners without unsettling the chassis.

Ground clearance (290mm/11.4") means you’ll grind hero blobs long before touching hard parts. The upright riding position allows for easy weight shifts, whether you’re dragging knees or popping wheelies. Just don’t expect plushness – the WP suspension, while adjustable, prioritizes feedback over comfort.

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Competition: How It Stacks Up

The mid-2000s supermoto arena pitted the KTM against three key rivals:

1. Honda XR650M:
   Honda’s air-cooled brute offered legendary reliability but weighed 23kg (51 lbs) more. Its softer suspension and lower seat height appealed to beginners but felt numb compared to the KTM’s telepathic handling.

2. Husqvarna SM610:
   The Swedish contender matched the KTM’s power but used a carbureted 576cc engine. Its six-speed transmission was better for highways, yet chassis flex in hard corners gave the 660 SMC an edge.

3. Aprilia SXV 5.5:
   Aprilia’s V-twin rocketship made 70 HP but required rebuilds every 10,000 km. The KTM’s maintenance intervals looked downright lazy in comparison, making it the pragmatic choice for daily riders.

The 660 SMC carved its niche by balancing race DNA with (relative) practicality. It wasn’t the fastest or most comfortable, but it delivered undiluted supermoto thrills without demanding a mechanic’s salary in upkeep.

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Maintenance: Keeping the Beast Alive

Owning a 660 SMC is a commitment – but one that pays dividends in riding joy. Key considerations:

Valve Checks:
With intake and exhaust clearances at 0.12-0.15mm (0.0047-0.0059"), inspections every 1,000 km (621 miles) are crucial. Use quality feeler gauges and always check when cold.

Oil Changes:
The 1.9L (0.5 US gal) capacity demands JASO T903 MA-rated 10W-50 oil. Change every 3,000 km (1,864 miles), more frequently if you’re a habitual redliner.

Carb Tuning:
The Mikuni BST40 benefits from annual diaphragm inspections. Keep the pilot jet clean for smooth low-RPM operation. The factory-recommended 2 turns out on the air screw is a good baseline.

Cooling System:
Use distilled water with corrosion inhibitors (KTM’s “Wasser+” specification). Flush annually, and check the radiator fins for debris after off-road excursions.

Chain Care:
The 5/8 X 1/4” chain needs frequent lubrication given the single’s vibrations. Replace sprockets when wear reaches 16/38 teeth – uneven wear on the front sprocket is common.

MOTOPARTS.store Recommendations:
- NGK DCPR8EIX iridium spark plugs for cleaner burns
- Brembo brake pads (Sintered HH for aggressive riding)
- WP Suspension Fluid 5W for fork maintenance kits

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Conclusion: Timeless Thrills

The KTM 660 SMC remains a benchmark for pure supermoto exhilaration. Its combination of brutal simplicity and race-derived components creates an ownership experience that’s equal parts rewarding and demanding. While modern alternatives offer ABS and ride modes, the 660 SMC gives something increasingly rare – unfiltered communication between machine and rider.

For those willing to embrace its quirks (and keep up with maintenance), this KTM delivers adrenaline by the liter. And when parts do wear out – as they inevitably will on a bike ridden hard – MOTOPARTS.store stands ready to keep your Austrian beast terrorizing backroads for another decade.

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Specifications sheet

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