by Peter Walker

What is it that makes the bicycle and the demonstration such good companions?

When the location of this year's Climate Camp protest was finally revealed on Wednesday, the first activists to arrive were a select group in rented vans, tasked with setting up tripods and fencing off a section of the land at Blackheath, south-east London.

But shortly afterwards, the first influx of protesters taking part in the "swoop" on the site from a series of meeting points around the capital was a contingent of around 150 people, all riding bicycles. They – with me in tow – had spent about 90 minutes pedalling en mass around central London, awaiting word on where the camp would be.

It's a fair bet these days that whenever there is an environmentally based protest, particularly in an urban area, a gang of cyclists will be involved somewhere or other. In fact, bikes are becoming a must-have element of all sorts of modern civil disobedience.

Many of these bike-based actions are making a point about transport and cycling issues: Critical Mass, the group celebration of taking over a city's streets with bikes is a good example, and is held regularly in dozens of places around the world (it's on tonight in London if you're in town).

There are exceptions: last year activists from one Indian political party staged a bike rally to protest, somewhat counterintuitively, against a rise in fuel prices. And there is the long-established, if still baffling to some, practice of naked bike rides.

So what is it that makes the bicycle and the demonstration such good companions? To me, there are two factors at play.

Firstly, if you're in a group, there is something undeniably liberating about riding around a city surrounded by cyclists. I've never been on a Critical Mass ride, so going to Blackheath was a strange sensation – no longer a vulnerable solo rider lined up against the massed metal forces of the motorised traffic, I was part of an entity too big to ignore or shove unthinkingly into the kerb.

Second, if you're a solo campaigner in an urban environment then the bike is the mode of transport most guaranteed to get you to your protest on time and – perhaps more important still – give you the best chance of slipping away from pursuing authorities. When I worked for another news organisation in Beijing I'd regularly pedal to meetings or protests, nipping down narrow lanes to shake off the unmarked police cars, which routinely trail foreign journalists in China.

There is, of course, a catch for protesters: the police – at least in parts of the UK – have noticed this and now send officers out on bikes of their own. Some of the police riders look noticeably fitter and keener than they once did. Perhaps it's just a matter of time before we see Bullitt-style car chases around our cities – but this time on bikes.

This piece originally appeared on guardian.co.uk