Husqvarna engineers concentrated on the frame to make both models even lighter and easier to handle. To achieve this, the frame is of a completely new design with new levels of rigidity and settings for dealing with power that optimise handling and give the rider a much better feel for the bike. The frame is also one kilo lighter than before. All the new body panels have IPD (in–mould plastic decoration) graphics and are made of stronger, more flexible plastic. The front and rear lights are more powerful.

The rear cluster houses LED lights and an integrated dual purpose number plate holder that can carry either a homologation or a racing number without the owner having to buy additional parts. The front mudguard is also new. The new look of the bike is both eye-catching and different. Still on the subject of looks, the wheels are black anodised Excel rims and the new plastic engine protectors on both sides are also black. The newly designed side stand is made of aluminium. All the 2010 Husqvarna twin-cam engines now feature new radiator hoses and more powerful water pumps so as to improve cooling and performance.

The engine has a new over-pressure valve in the oil circuit, a new needle cage lubrication bearing and a new oil filter. The exhaust valves are made of steel to ensure longer life and reliability. The gearbox has been renewed to offer improved gear change speed and accuracy. Gearbox design has seen changes in terms of: gear change linkage, lever and selector mechanisms. The 450 and 510 engines have also benefited from a new timing gear chain tensioner that was introduced to improve chain tension and reduce contact pressure. The exhaust system has twin aluminium silencers that create a very special sound, reduce overall noise levels and improve performance.

The SM 630 first took shape as project 610 but the frame and engine were totally redesigned. The new completely designed bodywork gives an elegant, streamlined yet aggressive look. The saddle, tanks, side panels and front and rear mudguards are all newly designed. The saddle especially now has double depth padding to provide the rider and passenger with more comfortable seating for medium and long journeys. Passengers will be able to make use of two specially designed handles on the saddle frame that will let allow them to feel both safer and more comfortable.

The headlight unit is also new and houses a stronger lamp. This unit is built into the fairing that goes perfectly with the “racing” mudguard. The frame and rear swing arm are now black to contrast with the two new colour schemes available - White and aluminium and black and white. The white and aluminium version is more elegant and sober featuring “in mould” plastic decorations. The black and white version is sportier and more aggressive with fully painted bodywork. The rear mudguard is also new with LED lights and a built-in number plate holder.

The main news item on the new SM 630 is the engine that has been bored out from 98 to 100 mm to give a capacity of 600cc The head now has a red rocker box like the race machines and houses DOHC valve gear from the racing 450/510 that provides 20% more power than the previous 570cc version. The SM 610 i.e. now has an electronic injection system that was developed in collaboration with Mikuni. The engine now features a 45 mm throttle body with the starter command on the handlebars and there is a 300 Kpa Mitsubishi “twin jet” fuel injector fitted to the throttle. The pressure regulator (3 Bar) regulates any return of excess fuel to the tank and the MAQS (Modularised Air Quantity Sensor) consists of air temperature, mapping and TPS (Throttle Position Sensor) sensors.

The Kokusan 360W three-phase ignition flywheel is also new. The water temperature sensor is positioned on the head. The injection ECU processes signals and governs the operation of the solenoid-operated valve fitted to the right hand side of the radiator. The cooling system has a new impeller and pump body. The clutch is hydraulically operated and the left cover plate has been redesigned. New components include the rugged 12 litre polyethylene petrol tank with a 40l/h pump; the non-return fuel circuit has quick-fit connections. The exhaust system on the four-stroke single cylinder engine has a “closed loop” lambda probe and the twin aluminium silencers feature catalysers that have been redesigned and optimised to meet Euro 3 requirements.

The areas on the silencers that houses the catalysers and around the passenger footpegs have been covered with stainless steel protection. The chassis can be fitted with a main stand that is available as an optional extra. As regards the brakes - the front now has a radial race-derived Brembo caliper acting on a floating 320 mm disc while the rear has a 220 mm Brembo disc with a single piston caliper. The suspension remains unchanged except for the Marzocchi forks that now have the same black sleeves as on the 450 and 510 models. The 2010 version of the SM 630 will have Tommaselli tapered handlebars with new steering head clamps and no cross bar. Dry weight is 158 Kg.