I'm pumped up with joy over my new gadget

If you had to single out one person as having made the most important contribution to the development of the bicycle, JB Dunlop would be on the shortlist. In 1887, Dunlop, a Scotsman with a veterinary practice in Belfast, experimented with ways of making his son's tricycle more comfortable and came up with the pneumatic tyre. Without the bounce and grip that inflatable tyres give us, cycling would be pretty intolerable.

So I thought a few words on tyres would be in order. I'm prompted here mainly by my favourite bike-related purchase of the summer, a track pump - the sort that stands upright, with a rubber hose to connect to the bike and a plunge handle for pumping. Now I have one, I don't know how I ever lived without it: inflating tyres always seemed such a chore with a handpump; now a few swift plunges and I'm there.

The other great advantage of the track pump is that it comes with a built-in pressure gauge, from which I have learnt that I have been too timid by half about pumping my tyres up. Now I find myself getting mildly obsessive with keeping them like rocks; and on the occasions when I've let the pressure slip a bit, I'm struck by how spongy they feel - like riding on puddings.

Under-inflation is one of the commonest mistakes people make. Though, to be fair, it isn't really a mistake - how hard you keep your tyres blown up is a matter of taste and circumstances. If you prefer a softer, gentler ride, if you are riding off-road, or if - as has been happening lately - the roads are scorching hot, then go ahead, let a bit of air out. Generally speaking, though, if you're riding on Tarmac, tyres should be as hard as you can tolerate (if they don't give at all under your weight, you're overdoing it). The softer they are, the more energy they dissipate, and the harder you have to work.

In hot, humid weather, you soon start to feel the difference. If you're carrying a heavy load, you might want to add a bit more air, particularly on the back wheel, where the weight goes. The risk with flabby tyres is always that you might pinch the tyre between wheel-rim and road, leading to blow-out; and you lose some stability when, say, you take a corner at high speed. Experiment a bit, and see what works for you.

The other common misconception about bike tyres is that you need a tread on them. That's because people assume bike tyres are like car tyres, which they aren't.

With cars, tread plays a part in preventing hydroplaning, when the car glides along the surface of a patch of water. Hydroplaning isn't a problem with bike tyres, though. So that the rider can lean on a curve, bike tyres have a curved profile, which means water doesn't get trapped underneath. The curve also means that the contact patch, the bit of the tyre that touches the road, is tiny: maximising the contact patch, to provide a better grip, means keeping the rubber as smooth as possible.

Off-road is a different matter: tread works better on loose or rough surfaces. Plenty of tyres offer a mixture - since I do a bit of riding on dusty trails, I use tyres that are smooth on the bottom with a bit of tread around the edges. Less lazy riders swap tyres for different purposes.

I can add two more pieces of wisdom gleaned from experience. The first is, a lot of modern tyres have a Kevlar strip that is supposed to prevent punctures: it really works - not 100 per cent, but enough to save you a lot of messing around with solvents. Unless you like that sort of thing. The second is, if, like me, you tend to lose the plastic valve caps, bear in mind that Continental inner tubes come with a lovely, highly visible yellow cap, while Schwalbes are see-through - madness!

Search for used cars