As with so many off-beat ideas, we have the French to thank for this one; it was Gallic two-wheeled hooligans who first put sticky street tyres on big off-roaders and called them supermotards - and now there's a World championship for them!
Suzuki's DR-Z400 SM is radical compared to your average street bike but quite mild by motard standards since it's derived from a remarkably civilised off-roader, the DR-Z400.
The 398cc, twin-cam single has an old-fashioned Mikuni 36mm carburettor with a manual choke (remember where it is, you'll need it) and kicks out a claimed 39kW at 7600rpm accompanied by 39.2Nm at 6600rpm.
Like most singles with big carbs, it works better when ridden hard; it will stumble and sometimes spit back if you ride it with delicate right-hand movements but give it big handfuls and you'll get great gobs of torque without hesitation.
The SM weighs all of 134kg and accelerates like a cobra striking, striking every gear as if it was prey. There are only five, but that's enough; forget the clutch and snick up when it stops accelerating, which happens much more quickly than you're ready for.
The SM goes up through the box to 140km/h hard enough to give serious sportbikes a run for their redlines, with another 12km/h available to those with elbow-room and a certain lack of mechanical empathy.
It is, however, reassuringly stable even flat out, which I wasn't expecting given its wide, off-road handlebars and lack of weight.
The clutch is light, positive and seemingly immune to heavy-handed road use - just as well, as there's no slipper clutch and you need to use it on downshifts.
Balance shafts take care of primary vibration, although a too-gentle hand on the twistgrip at low revs will induce ferocious power-thudding.
The standard DR-Z400 forks have been replaced by 47mm inverted Showa units derived from those on the RM250 motocross bike; I couldn't induce either flex or stiction in this superlative equipment but their too-soft spring rate allows alarming amounts of dive under heavy braking.
Mind you, once you get used to the bike's sudden changes of attitude, you realise it appreciably steepens the head angle and makes this quick-steering bike turn in even more abruptly with the brakes hard on - which takes a lot of nerve but makes it possible to turn inside almost any sportbike on the market.
Rear suspension is by an equally high-spec, remote-reservoir monoshock adjustable for high and low-speed compression damping. It's just as softly sprung as the forks; it doesn't make the rock-hard, too-narrow seat any more comfortable but the bike will hold its line on the bumpiest of tar roads.
Low-tech brakes
Braking is by low-tech, Nissin floating callipers on 310mm front and 240mm rear discs, hardly state-of-the-art but more than adequate for the SM's lack of mass. Several hours of hooliganising on a quiet Sunday morning induced no fade that I could detect.
The bike is, however, very thirsty for its size; the vacuum-operated fuel-tap can't supply enough fuel to keep the engine running with the choke on so you have to start on the straight-through "prime" position.
Naturally I forgot to return the tap to the "on" position once the bike was hot so when it stopped on a remote hilltop after only 130km there was no reserve: the tank was bone dry and I had to walk to the nearest garage.
Suzuki quotes a fuel capacity of 10 litres; the tank on the test bike overflowed at 9.75 - close enough. I had ridden 130.8km on that amount of fuel, which works out to 7.5 litres/100km, distinctly extravagant for a 400cc single.
Pit stops
Just be aware that you'll need a pit stop every 100km or so to be on the safe side.
What you get for that fuel expenditure is a buzzy, harsh ride on a ridiculously uncomfortable motorcycle with lightning-quick handling allied to extraordinary road-holding and stability, utterly limitless ground clearance and more attitude than an NBA basketball team.
I'm not sure I'd want to ride one every day but that Sunday was the most fun I'd had in years and isn't that what Sundays are for?
Price:
R47 900.
- Test bike from Suzuki South, Cape Town.