It may not be wireless, but ETC's Nine-O bike computer is super-slim and simple to operate. Mounted to either bar or stem, it gives you all the key readings in large ﬁgures.
It also has a temperature display, a speed comparator (which tells you whether you’re riding faster or slower than your average) and a graphic that shows whether you’re accelerating or decelerating – but that one is too small to make out easily. There are also ‘calories used’ and ‘fat burnt’ measurements, although we’d treat them with a hefty pinch of salt.
The backlight is a more useful feature, as is the ability to input a second wheel size – an extra mount kit comes as part of the package so switching over to another bike couldn’t be easier. Changing the battery is a bit awkward, though; even with the right tiny screwdriver, we struggled to remove the backplate.