I was supposed to be convinced that the acrobatic courage of three young athletes would be mirrored in the new range of 50cc and 125cc Runner scooters.

Take the words "credulity", "stretched" and "breaking point" and rearrange them to create a phrase PR people never want to hear. By the time I was introduced to a 12kW, 125cc Runner my natural cynicism was fully alert.

But Runners are not aimed at comfortable middle-aged motorcyclists with unrestricted licences who can afford 1100cc superbikes. They're meant for teenagers with attitude.

One approached me in a park in Bermondsey. "Is that the new Gilera?" he asked. "Cool. Where'd ya get it?"

I explained that I was test-riding it for The Independent and he proposed a deal.

Since it didn't belong to me he wondered if I'd mind turning my back while he pinched it.

Is that a recommendation? In this market it's probably the best you can get. The upside is that the Runner is technically good, too. Gilera calls it "a scooter with the soul of a motorcycle".

That's not complete fantasy: the top-heavy, hornet-shaped front end and tapered tail push the rider into a crouch vaguely approaching the posture needed to ride a sports bike.

There are three models in the new range: fuel-injected and carburettor versions of a 50cc two-stroke which is legal in Britain for 16-year-olds and four-stroke powered VX125. All are liquid-cooled.

The 50cc models use upside-down front forks and a rear mono-shock while the 125cc has conventional forks and twin hydraulic shock absorbers at the back.

Gilera claims quicker acceleration and sharper braking than its competitors, combined with low fuel consumption and emissions.

The VX 125 has the oomph to compete in London traffic. Pick-up is as near to instant as I have experienced and progress up to 80km/h is smooth and brisk.

But the best enhancement, common to all three models, is the new, large, lightweight alloy wheels. The Runner's front end now has a 14", six-spoke wheel and genuinely sporty 120/70 tyre while the 13" 140/70 rear gives a real sense of security.

The outcome is good handling and plenty of potential for the sort of stunt-riding young scooter fans so enjoy - in the safe privacy of deserted car parks, of course.

I preferred the simplicity of the Runner SP with its carburettor-fed engine to the fuel-injected Purejet version but the difference was marginal. The spritzer is even better for the environment and offers quicker acceleration (5.5second to cover 30m from standstill against 62sec). My advice is to ride both and choose according to feel.

The Runner is a scooter, not a revolution in the art of urban transport. But its sharp contours, signature Gilera headlight, in which twin lamps are covered by a single transparent sheet, and ultra-sleek profile do make it very pretty. The back-lit analogue-digital instrument panel is as comprehensive as any available at this level in the market.

All three Runners are fun. They can't leap between buildings but their rigid tubular steel frames make for excellent agility and precise handling, as does locating the fuel tank under the central tunnel to lower the centre of gravity

Specifications – Gilera Runner VX125:

Engine: Single cylinder, liquid-cooled 124cc four-stroke Piaggio Leader.
Brakes: 240mm disc at front, 220mm disc at rear.
Fuel capacity: 8.7 litres.
Running weight: 135kg.