Suzuki DR-Z400SM

"The supermotard is an extremely versatile motorcycle... it allows riders the freedom for off-road adventures and the practicality of road registerabilty, without compromising on exceptional performance and handling.

"We expect production supermotard machines to be the next big trend in Australia and we're excited about our first foray into this untapped market." So says Suzuki in its September 2005 announcement of the DR-Z400SM - its first attempt at this class of bike.

Supermotos are anything but new. Private owners have been converting dirt bikes to street use (or putting street bikes on dirt suspension) for many years and there have been plenty of notorious racers. One of the most ludicrous was Gallina's Gorilla, built in the late eighties from a Roberto Gallina-tuned grand prix 500cc two-stroke. The current crop tends to be singles (though Aprilia has developed a 450 V-twin), raced hard on a combined tar and dirt circuit.

The popular road format has been the typical big dirt bike converted to smaller laced rims (particularly on the front), grippy street rubber, lower handlebars and, well, that's about it really. They're simple enough to do, cheap to build and run and a hell of a lot of fun on tight roads. They're particularly effective on rough tar, typically showing a clean set of heels to a sports bike when the going gets rough.

They also happen to be pretty effective toys in the city, thanks to the narrow profile, high seating position, and they're ability to happy clamber over minor obstacles, like gutters. As one newcomer to the class recently put it to me, commuting on a supermoto becomes addictive after while - more like a game, rather than a chore.

Okay, so what are the down sides? Top speed, fuel range and long-distance comfort will pretty well cover it. They're not great tourers.

Suzuki has tackled the category in a way that's not so different to what private owners have been doing for years - which is grab a perfectly good dirt bike and see what you can do to make it tar-friendly.

The basis for the whole shebang is the company's DR-Z400 dirt bike, which has earned a good reputation for being a solid, value-for-money, machine for the average trail rider. The DR-Z engines, in 250 and 400 form, are very willing and tough units, happy to spend the day revving their little hearts out. So we're starting with a lively and known quantity.

Up front is where the big changes are, with the most obvious being a 17-inch Excel rim laced to the hub, which is carrying a fairly serious-looking 310mm single floating disc brake with twin-piston Nissin calliper.

The upside-down fork is derived from an RM motocrosser, according to Suzi, and revalved for the road. The single rear monoshock hangs off a fairly conventional alloy box-section swingarm, that carries a single-piston calliper for the rear disc.

Finishing off the chassis is a sticky set of Dunlop D208 radial tyres with 120/70 and 140/70 front/rear profiles.

When it comes to the engine, the changes seem to be subtle, while Suzuki is a little coy about the exact changes and what horsepower they produce. We do know the carburettor has been swapped from the 39mm dirt bike item to something with a slightly smaller bore (36mm) as part of an effort to ensure there's plenty of low-down urge. This actually reflects overseas tuning on some of the dirt versions, so the company is in familiar territory.

When it comes to equipment, there's a 10 litre fuel tank (good for up to 200km, depending on how hard you're riding it), no tacho, but a multi-function speedo with clock and trip meters. The latter is the same set-up found on the DR-Z400E.

So what's it like to ride? An absolute hoot - that's the short answer. Weighing a claimed 134 kilos dry, it's a cinch top flick around, particularly with the wide (by road standards) handlebars.

There's plenty of grip from the D208 rubber, and good feedback when you start to reach the ragged edge - something which the bike encourages you to do.

Suspension is plush and the only struggle road riders might have is getting used to the fairly extreme attitude changes under brakes and over a series of mid-corner bumps - the bike handles it all fine, but it can take a little getting used to.

One interesting conundrum is working out what riding style to use - typical road as in leaning with the bike, or more of a dirt style where the machine does most of the work. Both styles seem to be okay, though you can't help notice that a more dirt-oriented style is what the racers are using.

The powerplant is a hell of a lot of fun. People were condemning it for not being powerful enough before the bike was even released and I reckon they're wrong. In stock form, the SM is nicely balanced with just enough urge to scrabble near an indicated 160km/h and heaps of go up to around 130km/h

It pulls well at low revs, has a fat midrange (good, I'm told, for a bit of wheelie work), and the top end seems fine. No doubt you could get more out of the latter with a bit of tuning work, but it would be risking the good all-rounder nature of the machine.

Braking is ample, with nice feel and enough grip to have it standing up on the nose.

So what are the disadvantages? I must admit I'd be happier with a tacho; The seat gets hard fairly quickly; And the fuel range is limited. The last two, I think, are part of the nature of the supermoto beast (regardless of brand).

Price is well under $10,000, which seems pretty reasonable given the huge amount of fun you can have with this thing.

Specifications
Engine: 398cc, four-stroke, single cylinder,
DOHC, 4-valve, liquid cooled.
Bore Stroke: 90 x 62.6mm
Compression Ratio: 11.3:1
Fuel System: Mikuni BSR36
Lubrication: Dry sump
Ignition: Digital/DC-CDI
Transmission: 5-speed
Final Drive: #520 chain
Overall Length: 2220mm
Overall Width: 870mm
Overall Height: 1185mm
Seat height: 890mm
Ground clearance: 300mm
Wheelbase: 1460mm
Dry weight: 134kg
Front suspension: Inverted telescopic, oil-damped, adjustable compression and rebound damping
Rear suspension: Link-type, fully-adjustable spring preload, adjustable compression and rebound damping
Front brakes: Single hydraulic disc
Rear brakes: Single hydraulic disc
Tyres Front: 120/70-17
Tyres Rear: 140/70-17
Fuel capacity: 10.0L
Colour: Black
Price: $9590 plus ORC
Warranty: 12 months unlimited km