One value of cycling is that it keeps your inner child alive. More than alive, in my case: in rude good health and boisterous with it, frequently threatening to overwhelm the outer adult. Snow, as is forecast this week, can have the same effect. I remember one night, about 20 years ago, when the snow fell and settled so suddenly and thickly that main roads were deserted by traffic - yet full of people, strangers to each other but sharing in the pleasure of this unexpected transformation of the urban landscape. Spontaneous running snowball fights broke out, filling the flake-laden air with muffled whoops and laughter.

I don't expect anything like that to happen again. What we will get is a bare quarter-inch that will be gone by lunchtime. Trains will, of course, be cancelled, but the roads will be clear - except for a margin of dirty slush, there just to soak cyclists' shoes. Only the occasional car, which has come in from the country, will carry an enviable inch of snow on its roof or boot.

But I cherish the fantasy that perhaps I might one day get to combine these two innocent joys: cycling and snow. I did once try riding on snow, as it was settling on a road through Richmond Park, in south-west London. At first, it felt fine: the skinny tyre on my road bike cut through the thin layer of snow and bit into the asphalt. But then the snow became thicker and my little inch-square of rubber was just running in a groove of packed snow, and all of a sudden the handling felt distinctly dicey. When you know that the slightest steering movement or braking effort would be a bad idea, it's generally the right time to get off.

But if I'd been on a mountain or cyclocross bike, with knobbly tyres, I could have ploughed on as long as I liked. Given a decent tread, fresh snow is actually a fine surface to ride on, giving surprisingly good grip and being generously progressive at the limits of adhesion. Hard-packed snow, particularly if it has had the chance to re-freeze, is less forgiving. You have to watch carefully for ruts that might trap your wheel like a tramline or icy patches where you can only try to relax, do nothing but coast in a straight line and hope you reach a surface with some traction soon. If you can hear your tyres gently crunching as they roll, all is fine; silence is ominous.

In places where they have serious winters, serious cyclists invest in studded snow tyres, which have little pointy carbide nipples set in each rubber block of the tread. They may sound like accessories for an S&M scene, but these can cope with almost any surface short of a pristine skating rink. Handy if you're pondering a trans-Siberian tour, but overkill, possibly, for the British climate. It's good to know, though, that we can do the white stuff if we have to.