It's not the best of starts. I've only been in the saddle of this new bicycle – the centrepiece of London's cycle hire system, set to launch on 30 July – for two minutes and I'm already being flagged down by a policeman. What have I done wrong, I wonder nervously. Did I cut across someone when changing lanes on the approach to Westminster Bridge? Should I be wearing a helmet? It's been three decades since I passed my cycling proficiency test, and there's been very little serious cycling in between.

The policeman points to the spot on the curb when he wants me to park up. "What have I done, officer?"

"Oh, nothing," he says. "I just wanted to ask what the bike was like to ride. Do you think it will be popular?" Squeezing the brakes and ringing the bell, he's like a wide-eyed boy in a bike shop. I offer him a go. "I can't," he says. "I'm on duty."

It strikes me, during this rather surreal exchange, that at least the bike isn't suited to being a getaway vehicle. It weighs more than 20kg, and has three gears: Sloth, Tortoise and Ageing Elephant. It's designed for leisurely ambling rather than APD (aggressive pursuit of destination), which is clearly the default setting of every other cyclist on the road today. The looks of disdain and irritation are palpable as they continually whizz past me.

After Paris, this will be the world's second-largest urban cycle hire system. The scheme, vigorously promoted by London's mayor Boris Johnson, will eventually see 6,000 bikes parked at 400 "docking stations" spread every 300 metres or so across central London (although the latest in a string of delays means only pre-registered "members" will be able to take out the bikes from a week on Friday, with the wider public only getting their hands on the bikes at the end of next month). After paying a daily access fee of £1, and providing details of a credit card for the deposit, the first 30 minutes of bike use will be free, although the price escalates rapidly as the clock ticks on (£1 for an hour, £6 for two hours, £35 for six hours).

My first impressions of the bike, riding it from Victoria to Borough and back along the South Bank, are good. Yes, it is heavy – you're never going to overtake Lance Armstrong on this thing – but it needs to be built to last, and be thief- and vandal-proof, a problem that has blighted other systems around the world (particularly Paris). It is purposely not designed for long rides: the pricing structure encourages sub-30-minute journeys and, given the limited geographical spread of the distinctive blue docking stations, it is not yet a bike aimed at commuters. Rather, it is there to replace a short taxi ride, or a two- or three-stop tube journey.

The bike has an adjustable padded seat, smooth handling, a guard to protect your clothing from the oily chain, a bell and dynamo lights. But there are problems. The lack of mirrors is a minor grumble, but understandable given how easily they might snap off (tip: carry your own clip-on mirrors). A far bigger inconvenience is the lack of a basket or a security chain, both of which come as standard on the Vélib' in Paris. Instead, the London bike has what can only be described as a magazine rack. You could carry a Sunday newspaper in it, but not much else. And rather than chain it to a lamppost when you pop into the shop to buy said paper, you will have to find a docking station or risk losing the £300 deposit should it be stolen.

My other criticism is that you've got "Barclays" plastered all over the bike. Sure, London wouldn't have this new bike without the rumoured £25m that Barclays has paid to sponsor the system for the next five years, but the prominence of the branding earns me a heckle or two as I pass the peace protestors camped out at Westminster Square.

And then there is the name. Parisians have fallen in love with the Vélib' – a portmanteau of velo (bicycle) and liberté (freedom). Londoners are, one feels, less likely to fall for the Barclays Cycle Hire, as the bike is officially known. Freecycle is already taken, but this bike urgently needs an affectionate moniker (The London Wheel? The Big Ben? The Bumbling Boris?) if Londoners are to develop the same levels of affection.

Another key to the scheme's success, says Tom Bogdanovich, campaigns manager at the London Cycling Campaign, will be avoiding the "Montmartre effect", whereby users arrive at popular destinations only to find empty docking stations. (In Paris, the steep hill at Montmartre means users invariably only hire the Vélib' to ride down the slope rather than up, leading to a noted shortage of bikes at the top of the hill.)

"London has the great benefit from learning from the experiences in Paris and Barcelona," Bogdanovich says. "Getting the distribution right is key: it's crucial that people have easy, immediate access. As the system moves on, they must respond to patterns of use and identify where the highest demand is. It would make sense, for example, to think about expanding it to Canary Wharf and the Olympic zone."

Bogdanovich says an estimated 250,000 people cycle in London every day, and that one in three people are "interested" in cycling. "But that's still way behind cities such as Amsterdam and Copenhagen. The system should take advantage of the fact that London is a cluster of villages. Hackney, for example, has very high cycling rates – 10% of all journeys. Also, the average bike journey in London now is 3.5km, yet this system is largely aimed at replacing short tube journeys in central London. Over time, the system will need to serve both demands."

Leo Hickman enjoys the Vélib' hire bike in Paris. Photograph: Graeme Robertson for the Guardian

Four hours after handing my trial bike back to a Transport for London official, and one Eurostar trip later, I am standing outside a Paris apartment adjacent to the exquisite Jardin du Luxembourg on the Left Bank. The apartment belongs to Eric Britton, an American who has lived in the French capital since the late 1960s and who now acts as an international consultant and commentator on sustainable urban transport systems. He's a huge fan of the Vélib', which launched to much fanfare and enthusiasm three years ago this month. He immediately probes me for first impressions of the London bike.

"Yes, it is a big error not to include a lock-up and a basket," he agrees, as we walk to his nearest docking station. "Around 90% of Parisians use the basket on their Vélib'. Ladies' purses, backpacks, shopping bags – they all go in there. I also think the London scheme is too small. Paris, which is a smaller city, launched with almost twice the number of bikes and stations."

Still, Britton is broadly optimistic that London's bikeshare scheme will be a success: "The real genius of the systems in both London and Paris is that the first 30 minutes are free. It needs to be 100% ready on day one, though. All the problems need to be ironed out, otherwise people will conclude it's not worth the effort.

"Over time, you will see the bikes starting to occupy the terrain. Slowly, they will increase and gain more of the roadspace. Then the demand for more bike lanes will increase. We've seen this in Paris. Such a modal shift takes a little time, but it is happening here."

Britton shows me how easy it is to undock a Vélib'. As an annual subscriber, he has a swipe card which gives him instant access. I have to use my bank card to gain access via the electronic terminal, though, which delays things for a couple of minutes.

Britton shows me how to quickly scan for the best available bikes: brakes, tyre pressure, seat, gears, a spin of the back wheel – a habit he says is now instinctive for most Vélib' users. It has also become etiquette, should you have a faulty bike, to lower the seat and turn it to face backwards to indicate to other users not to use it. (Each docking point also has a "spanner" push button to mark the bike down as needing a repair.)

The Vélib' is virtually the same bike as the London one, except for the sizeable basket and chain lock. But whereas I had a gleaming new model to try out in London, most of the Vélib's I see in Paris are displaying signs of heavy use. I pick a bike with a handle grip missing. Graeme the photographer discovers, in the middle of a fast-flowing intersection as we head towards the Eiffel tower, that his chain has a tendency to slip at the most inopportune moments.

Nevertheless, it is immediately apparent what differentiates Paris and London in terms of cycling experience. Paris's wide boulevards and avenues, with their separate side lanes now converted into cycle lanes, mean cyclists can regularly escape the near-constant close contact with heavy traffic that London's cyclists must tolerate. Despite the launch of London's first cycle "superhighways" for commuters yesterday, it is hard to see how other city's urban topography can ever be drastically altered to counter this.

But Britton's most surprising observation is that the Vélib' hasn't done much to reduce road traffic in Paris. Rather than get people out of cars – it is reckoned to have substituted only about 10% of car trips in central Paris – it has done a far better job of getting people off public transport. As many as half of all Vélib' trips are estimated to have replaced Metro or bus journeys.

Before I depart Paris, I meet up with Albert Asséraf, a strategist at JCDecaux – the advertising corporation that runs the Vélib' in return for a 10-year exclusive contract to use the city's 1,500-odd digital display hoardings. I ask what lessons London can learn from the Paris system, particularly after JCDecaux director general Rémi Pheulpin's comments last year that the Paris scheme was not commercially viable because of the extent of the theft and vandalism.

"Since we launched in 2007, we have expanded to 1,750 stations across the city and neighbouring suburbs and now have a maximum of 24,000 bikes in operation at any one time," he says. "To date, we've had 9,000 bikes stolen and 9,000 bikes vandalised. Most thefts are caused by day users because they are not used to how the docking systems works and they leave the bike accidentally unsecured. We have worked hard to communicate the message that these bikes are 'ours' – they belong to all of Paris, and it is a system we should be proud of. London should do the same."

Asséraf says the average journey on a Vélib' lasts 21 minutes and covers 2km, but that to counter the aforementioned Montmartre effect, users are now rewarded for returning their bikes to unpopular docking stations on hills (bikes are also redistributed around the city in trucks).

"We now give users 15 minutes' free credit if they return a bike to a so-called 'altitude' station. It's little lessons like this that London will need to learn. And London should make sure the stations are well stocked, even during the night. About 15% of all Vélib' journeys occur after the Metro shuts down and people want to get home without paying for expensive taxis. The Vélib' has become part of our lives – Parisians just can't imagine Paris without the Vélib' now."