Name: The Brompton.

Age: 40.

Appearance: Mangled kid’s bike, left on a verge as a cautionary installation.

What is it really, though? A folding bike.

You mean it’s supposed to look like that? Yes, but only when folded up. Unfolded, it looks like a practice unicycle: high-seated, small-wheeled, odd.

Ah yes, like the ones they use for that giant clown parade that wobbles through central London every weekday morning, rain or shine. Those are commuters, and the Brompton - invented by Andrew Ritchie in his London flat in 1975 and named after the adjacent Brompton Oratory – is their chariot.

And what of it? Brompton has just announced plans to move to a new factory in Greenford, west London, double the size of its old one.

Why? Surely everybody who wanted one of their funny little bikes has got one by now. Not so. They’re particularly popular in Japan – up to 80% of Bromptons are exported, and the company hopes to increase production to 100,000 bikes a year by 2021. There are even plans to develop an electric Brompton.

A folding motorbike? Not exactly. It’s a so-called “pedelec” design, whereby some of the person-power applied to the pedals is stored by a battery and released when assistance is needed on inclines. It’s more efficient, and you don’t arrive at work perspiring.

You also get less exercise. The Brompton isn’t really aimed at the fitness enthusiast. It’s for ordinary city-dwellers who are trying to get to work.

And don’t care how they look doing it. They care how they look when they get there. Brompton chief executive Will Butler-Adams vows to “get rid of the sweat and Lycra” associated with commuting by bicycle.

They do have a certain quirky utilitarian charm. How much will one of these everyman commuting machines set me back? About £900.

I could buy a proper bike for that! But then you wouldn’t be able to lug it around with you all day like a really heavy briefcase.

I’ll cope. Fine.

Do say: “Another example of great British design, admired across the globe.”

Don’t say: “And when it’s folded up like this, you can throw it right into the middle of the canal.”