Thomas Sutcliffe: The Critic

I went for a bicycle ride the other day – not a particularly noteworthy event, although this one had a higher cultural content than most of my trips. Indeed, it reversed the usual rule, which is that time in the saddle is one of the few periods that can be absolutely guaranteed to be culture free. Travel by Tube and you feel an obligation to crunch a few pages of the latest Philip Roth, or read a catalogue essay about the exhibition you've just attended. On a bike, on the other hand, all you can do is think – and most of my thoughts are taken up with how I can best avoid adding to the year's accident statistics.

But last week was different, because this ride had been organised under the auspices of the London Festival of Architecture, which has added guided cycle rides to its programme of walks and debates and exhibitions. As far as was compatible with continued survival, the participants were being encouraged to think about buildings and design and the urban landscape as they pedalled from site to site. And I found I learnt two things from the experience.

The first wasn't really about aesthetics, strictly speaking, more an experiment in fluid mechanics. And that was that, while an individual cyclist can get through the city as rapidly as any form of transport available, an architecturally curious peloton of 25 cyclists is a far more sluggish thing. Pointedly sluggish, in fact, given the peristaltic stretch and contraction with which it moves through the streets. And, as you might imagine, not all motorists were happy to find themselves waiting for the full length of the slug to emerge from a side street – a practical reminder that the design of cities often comes down to such street-level friction.

But the real architectural lesson came when the tour ended in the foyer of Allies and Morrison, one of Britain's most successful architectural practices. This was filled with meticulously crafted models of proposed buildings, including the Renzo Piano "shard of glass" near London Bridge and the Jumeirah tower intended to stand at the southern end of Blackfriars Bridge.

These were, I would suggest, the kind of objects that the word "architecture" would conjure in the average person's mind – all dazzling externals. But then one of the guides, gearing his address to the kind of audience you tend to get on a bike tour, explained how little parking for bicycles was currently designed into some of these buildings. Indeed, Piano's shard plans to provide only one bike space for every 25 staff, though current trends suggest that many more will be needed.

It sounds bathetic, of course, when set beside those beautiful models. On the one hand, bike racks; on the other, visions of a crystal city of the future. And yet the truth is that architecture is probably nine parts the former to just one part the latter. The façade might sell the building and capture the imagination, but it's the bike racks and their equally uninspiring nuts-and-bolts equivalents that will seriously affect how we live in the city. Architecture isn't just a glittering envelope, however thrilling that can be. It's the machinery of living that it encloses – and the machinery should work.