Priced at a very competetive five grand, fast enough to scare the living crap out of most passengers and trustworthy enough to be, erm, trusted; these Ducati 600s are begging to be taken seriously. Mark Forsyth and Trevor Franklin try hard to be serious...

The Mostro was struggling to get past 100km/h. The speedo needle wheezed through the last few numerals; 97,98,99, 100." God this is slow for a 600", I mumbled to myself while trying to assume a more aerodynamic shape. Being late for work on a bike barely capable of cracking 62mph into a head wind is frustrating. But I was being stupid. Very stupid.

It wasn't until I got to work that I realised the speedo wasn't a km/h speedo but a proper, UK spec mph one. I'd just spent the past ten miles sitting, not at 62mph, but lOOmph. Past the police station roundabout, down slip roads, and past every car on every road. I thought everybody was driving slowly that morning. Duurrrr.

After this little oversight, life with the 600 Mostro became much more bearable. The sit-up and beg riding position, low footrests and wide bars made perfect sense for everyday rides to work and back.

Little things like looking over your shoulder to overtake, change lanes or join a motorway (crap mirrors) were made much easier because of the riding position. After years of riding race-replicas I forgot how easy looking over your shoulder is when your bum isn't up in the air and your hands aren't down by the front wheel spindle.

The obvious difference between the Mostro and the 600SS is the fairing, or lack of it. The absence of a fairing wasn't a problem for me at all. Largely because, a) it's not fast enough to matter and, b) the big headlight and low seat give a certain degree of wind protection anyway. Once the speedo shows 110 mph there's precious little left except on a steep down-hill with a 90mph tail wind and a full racing crouch. Out of the two bikes I'd plump for the unfaired version. It felt physically smaller and more manageable. It looked better too.

Painting a picture of 100mph flat-oot top-end potential doesn't really do the Mostro 600 justice. OK, so it may only produce 48bhp but put it another way; you can safely wring its neck everywhere without feeling it's going to get the better of you. Can you say that about your Fireblade? No, of course not. Riding the Mostro on poor surfaces or wet roundabouts with this no^ surprises power delivery is easy, concentration and physical exertion don't figure. It still sounds like a Ducati when both throttle slides are fully open and the cylinders are gasping for air, but it feels like its wings are clipped by emission regulations. Pass me that Termignoni exhaust system and S&B filters Eugene and bugger the latest EC legislation. This motor (basically a 600 Pantah) is capable of producing a reliable 70 or so bhp. Forty eight bhp is a bit of an insult but the rest shouldn't be too difficult or expensive to liberate.

Insulting power levels or not, the Mostro is still stonking good fun. Low final gearing and handlebars more RM250 than 600 Duke make it the ideal wheelie-merchant's bike; maybe not as ideal as the 900 version but pretty good anyway. The slick five speed gearbox and robust clutch help. Changes can be made and trusted to stay firmly in place; the clutch can withstand all kinds of abuse without ever becoming grabby or unpredictable. After all the big Dukes this is an unexpected delight. The 900s (851s and 888s too) have a horrible ' ; clutch that doesn't always do what the rider wants. The Mostro's top gear is something of an overdrive, the motor feels very relaxed at 70-80mph.

Handling? Well, the 600 Mostro looks to have all the right gear; USD forks and a shock with a suspiciously Öhlins-yellow spring. But the reality is a little less exotic. The damping and springing front and rear is F.hard, hard enough not to wallow or bottom out (ever) with a passenger on board. Solo, the Mostro is prone to feeling a bit skittish on the biggest, baddest bumps. Rippled surfaces are the worst, there is just too much damping to allow the suspension to react for the next bump. To make matters worse the forks are also prone to stiction (this may become less pronounced as the forks bed in). But this is only a minor whinge; most of the time the Mostro feels taught and predictable especially through fast, fourth and fifth gear corners. It turns quickly (very quickly thanks to the leverage from those enormous handlebars) and toes the chosen line like a spineless back bencher with shaky job prospects. But at low speed the restricted turning circle (30°) is more than a pain in the rectum, especially when you've got to do a U-turn in a narrow lane.

The ideal Mostro 600 habitat is a twisty B-road. It likes nothing better than grunting between corners getting flicked left to right. There's no need to stamp all over the gearlever between corners because the power couldn't be better suited to being rolled on and off without sacrificing velocity. Mid-range power is there, not masses of it, but enough to keep most other bikes in sight. The only real handling flaw is the lack of Ground Clearance.

You don't have to try very hard to clout your feet on tarmac. Elaborate, low-slung footrest hangers put your feet dangerously close to terra firma and constant contact is almost inevitable. But it's the pipes that cause the biggest shock when the front leading edges of the enormous silencer cans touch down. Throw the Mostro into a turn too hard and it can lift the back wheel in the air when the pipes deck. Not nice, and something you have to keep in the back of your mind all the time when the roads are dry, especially when you're riding with other people on different bikes. What was I saying about the Termignoni system?

So the Mostro is good but it could, without spending too much money, be much better. Fit the footrests from the 600SS, remove the standard (wobbly fitting) exhaust system and replace it with a slightly louder, better tucked in one. Replace the standard air filter with a more free flowing set-up and re-jet carbs to suit. Job done. Then, perhaps, the performance would rival most other 600s on the market but with a bargain-basement price and the looks and feel of a Ducati. What could be better?

600SS

It went like this. "That's never a 600 is it?" "Yes."

He wasn't the last either. Luscious red paint, trellis frame and the fabulous engine noise of an air-cooled V-twin make you think of bigger Dukes. It's an easy mistake to make — until you ride it.

The 30.3 in seat height is low — less than a Kawasaki AR50 (30.9in) — and the reason for the girlfriend's hysterics seeing me riding up the drive. Wearing waterproofs and rucksack I must have dwarfed it.

Clip-ons mounted under the top yoke and a seating position that puts the boney parts of your bum plumb onto the ample seat foam make the SS less cramped than it looks.

Rubber topped footpegs positioned low (tarmac catchers) prevent knee-cramps you normally get on small bikes. This makes long distance riding a doddle. The pegs also damp the engine vibes that affect the bar grips (more noticeable on the left bar without the throttle tube).

The fairing works well. Both screen and lowers cut the breeze and keep legs fairly free from surface water (three storms on one 185 mile journey). The mirrors aren't so good. Three quarters of the rear view is obscured by shoulders and elbows.

Factory finish is excellent. Paintwork on the fuel tank and tail/side panels were scuff and scratch-free even after constant attacks from magnetic tank bags and sling overs.

Myopic Metro drivers are something else. A 20mph bumper-to-fairing impact bent a frame mount and cracked the fairing around the screw area. To keep mobile the mount was hammered straight and a large penny washer held the fragmented plastic together. Not many race-reps would get off so lightly.

Ducati's steel trellis frame has been around far longer than any alloy types. The 600's chrome-moly, lattice item is developed from the '84 750F1 (based on the 6001T F2 racer) and has hardly altered.

Easy engine access for servicing and removal is a good reason, the main one is it'll cope with more power than the SS motor could ever thud out and, more weight and abusive riding than I could heap on it (Bloater Hargreaves might find the limits). Rigidity and lightness have a downside by clearly showing up minor faults in the running gear.

Marzocchi USD front forks work fine at constant speeds, soaking up the bumps. They dive badly though, using up all the fork travel when hard on the front brake. There's no adjustment to cure this so do as I did; wbrry not and carry on.

The single rear Boge shock is fully adjustable. On standard settings it pitched me out of the seat twice. There's a thin line between hard and soft on the adjustment but, two tabs later, I reached a compromise by backing off everything, including preload. No more major jolts but still firm enough to feel the rear tyre working. Forsyth felt it was still too harsh, he noticed road ripples where I couldn't.

First pull on the single front disc is not a pleasant experience. You need four fingers, lots of pressure and everything happens later than you think. It's worse in the wet which suggests a duff pad compound.

Holding a tight line is the bike's ace when pitched against the Mostro in a brain out back-to-back thrash.

Unflappable is the word. Aim in the direction you want to go, any gear, throttle against the stop with hot Dunlop Sportmaxes and it'll stay there. Mark and I swopped bikes. The Mostro runs wide, wider still if you're off the throttle mid-corner. Two possible reasons: the Mostro's sit up and beg style puts more weight over the rear wheel letting the front wander or, the replacement Michelin tyres didn't suit.

If the Mostro is exciting to ride on B-roads (bouncing around, pegs and exhausts leaving a trail of spent aluminium) then the SS, flat out and scraping either footpeg, is exhilarating. What a gas!

All that from a 583cc, 2 valves per cylinder V-twin motor; I'm impressed. The sound of an air cooled Ducati twin on full chat is fairly intoxicating no matter what the engine size. Low down urge starts at 3,000rpm and drives through to 8,000.

Cruising at 70mph (4,8O0rpm), the motor is in lazy mode with no vibes. All day at 80mph is no problem but, 30 miles at 90mph the vibes get bad  bad enough for me to take my left hand off the bar and let it flop downwards to get some feeling back. That, and the ring of piston slap bouncing off the fairing sides are the only criticisms of the engine.

As a press test bike it's undoubtedly suffered from wheelie jockey torture. God knows why, with only 46.5bhp and a tall first gear it's not designed for that sort of abuse.

Gearchanges need minimal foot pressure when you cog up with the faultless hydraulic clutch. This surprised me, I expected the full crunch syndrome from an antiquated engine design.

Riding the 600SS for two weeks converted me from doubter to someone who can't wait to get his leg over another air cooled Ducati. You find brake and suspension niggles on all makes of bikes, why should the 600SS be any different?