'Think big' shouts David Eales as I wobble ungracefully away from him, down a narrow, car-lined road.

I feel like an overgrown child from a heartwarming movie scene, except I'm not making my bid for independence down a gently rolling park hill but out onto the mean streets of London.

Strictly speaking they're the much less scary back streets of Brentford, but for someone who has never cycled on the capital's roads they're plenty intimidating.

This is where I must confess childhood impatience got the better of me; I never learned to cycle in my youth and still pedal with all the composure of a drunk rodeo rider.

I'm trying to put that right by taking a course with instructor David Eales, director of the not-for-profit organisation London Bike Hub, which trained some 700 children and half as many adults across the capital last year - mostly in Hounslow, Ealing and other west London boroughs.

The company, which has a base at Brentford Works, in High Street, Brentford, open every Wednesday, from 7pm-9pm, and Sunday, from 11am-2pm, is involved in all things two wheels.

It runs cycle maintenance and training sessions, after-school clubs and community projects for people with mental health problems. It also sells refurbished bikes, rents out cargo trikes to small businesses and even helps people transform old bike parts into jewellery and accessories.

I'm taking one of the firm's free cycle courses, funded by Hounslow Council, which are available to people of all ages who want to get on their bikes more to improve their fitness and cut their travel costs.

The two-hour lesson begins with a brief word about your bike and cycling gear. Any worries I've turned up ill-prepared, in my usual work gear of khakis and leather shoes, are soon banished.

"Cycling isn't an extreme sport and it shouldn't be treated as such. It's a form of transport and you don't need to wear Lycra or specialist cycling shoes. You just need a bike you're comfortable on," he says.

We warm up with a few laps of the park, where David runs me through the road safety basics.

His first tip is to always push off with your right foot on the pedal because it means you're more likely to fall to the left, out of the way of following traffic.

The key thing when turning, he says, is to signal clearly with an outstretched arm, not simply flapping your hand, after looking over your right shoulder.

My unsteady manoeuvring means the threat of oncoming buggies and dog walkers is enough for me to contend with but David thinks I'm ready for the road so off I reluctantly set.

He quickly yells out 'think big' but it's not my dreams of powering up the Alpe d'Huez on the way to Tour de France glory to which he's referring.

He's simply encouraging me to think of myself as if sat at the steering wheel of a car and not be afraid of occupying the centre of the lane.

Too often, he says, cyclists are intimidated by impatient motorists and squeeze up close to parked cars to let traffic pass, putting themselves at risk of opening doors.

'A door and more' is another of David's favourite mantras, referring to the amount of space you should allow yourself.

It's the same case when you come to a junction, where most accidents occur. If you're too close to the kerb, rather than in the centre of the lane, or towards the right if turning that way, you're more likely to be flattened by a car turning alongside you.

"Don't be put off cycling in the middle of the lane just because the driver behind is honking at you. Your journey's just as important as theirs," says David.

Luckily I don't encounter any overly aggressive drivers but I put into practice his tip of making eye contact with those I do meet.

David's favourite phrase is 'see and be seen', and looking motorists in the eyes is the best way to ensure you've achieved the later.

Apparently psychologists have suggested it also makes drivers think of you more as a real, highly crushable person and less as a rival road user, thus boosting their awareness.

With the lesson over, it's clear I've got a long way to go. But it's given me the confidence to think that with a bit more time in the saddle cycling could be a realistic alternative to the tube and buses.

David himself only took up cycling seriously fairly late in life, after his doctor said it would help strengthen muscles in his lower back and reduce the pain caused by his sciatica.

As well as improving your fitness, he says cycling can be good for people's mental health because it is a such a sociable way of getting about.

Cycling hit the headlines last November when six riders were killed on London's roads within a fortnight , but David insists it is still very safe . "You're more likely to die on your sofa than you are on a bike," he says.

A blanket 20mph speed limit on all but major roads in the capital and more efforts to discourage motorists and encourage cyclists, like swapping car parking places for secure bike racks, are top of his wish list to make London safer more cycle friendly.

But he is impressed with Hounslow Council's steps to promote cycling, which, as well as free cycle training, include:

* plans for a 'Skycle' route, linking Heathrow with central London, for use by airport employees and short-break holidaymakers

* plans for a 10km 'Greenways' network of cycle lanes linking parks and open spaces in and around Feltham

* a target to more than double the number of bike trips made in the borough per day, to 30,000

* Voluntary training for lorry drivers to improve awareness of cyclists.

* For more about free adult cycle training in Hounslow, available as part of the council’s Travel Active programme, visit www.hounslowtravelactive.co.uk, email getactivehounslow@smuc.ac.uk or call 020 8240 4211.