Recently bike computers, like smartphones, have been getting bigger. Just look at Garmin’s Edge 1000 compared to the Edge 810. And that means more space on your bars/stem taken up, or you’ll need a bigger out-front mount. Want to fit the 112mm Edge 1000 on your 100mm stem? Good luck with that.

Some people might not mind having valuable cockpit space impinged upon by technology, but others like to keep things neat and streamlined and it’s for that reason it’s a good idea to think about where you’re going to want the computer to sit.

You’ll also want to think about screen size and quality. If you really want a tiny bike computer there are some seriously small ones on offer, not least Lezyne’s new Mini GPS, but you need to make sure that you can cope with that small a screen. No, we’re not being patronising, it’s just that bike computers should be visible enough that you can just briefly glance down at the bars when you need to, without any prolonged looks (because looking where you’re going is more important). It’s part of the reason the out-front mount became popular is that it not only moves the computer off the bike, it moves it to a position that’s more visible.

You also need to think about the relationship between the screen size and the computer’s features. For instance, Garmin’s biggest computer, the Edge 1000, is also its most feature-packed, with navigation and all the rest of it, while the Edge 200 only records data.

There’s also the choice between black and white and colour. Colour generally only feature on the top devices – Garmin Edge 810, Edge 1000, Polar v650, Bryton Rider 60 and so on – and is only useful with certain features. For example, colour really adds something extra to maps, but has very little to offer on a standard numerical data screen.