A question in our mailbox. "I've noticed that you see very few cyclists using their phones as bike computers, even though I think it can be done just fine. Why is that anyway?"

Do-it-all

The questioner's observation is correct. In the lockdowns you did see some more phones on or off handlebars, but only rarely among the more avid cyclists. This is not so strange; although a phone can indeed be used as a bicycle computer:

• Of course, you have to invest in a holder. That can be something cheap of eBay/Ali for a few euros or an expensive solution such as Quadlock. If you only use it to log your ride you can of course put it in your back pocket.
• The GPS chip can measure speed quite well.
• If you also want to see heart rate, cadence or power you can connect sensors via bluetooth.  You can also connect a speed sensor that way, if the GPS chip is not sufficient.
• There are numerous apps that allow you to log your ride, turn your phone into a bike computer or navigate.
• The screen of a phone is nice and big so also suitable if you have bad eyes.

Also many disadvantages

So far no problem, you would say. Yet there are plenty of drawbacks to consider:

• Mainly older phones are not waterproof. In case of rain you have to stow it away in your back pocket.
• The GPS chips in phones are not waterproof.
• There is risk of damage when you crash. Not nice, with an expensive iPhone or Galaxy of 1000 euros.
• The battery life is limited (backlight and GPS are running continuously).
• There is a risk of being distracted by, for example, incoming apps.
• A phone does not have a barometric altimeter. Not a problem when you live on flat land, but it is a problem when you are climbing.
• You also want to be able to use a phone in emergency situations. If you've crashed on a lonely road you want to be able to call your partner or 112. And if your phone breaks down, you won't have a backup to find your way around either.
• Phones are pretty big. Not everyone likes the look of that.
• Many apps require an internet connection. Not a problem in some areas, a different story in the high mountains.
• There are not many apps that can do the bike computer function, navigation and logging all at the same time.

Moral of the story. It can work just fine, provided you're not too demanding. A phone is a Swiss army knife: it can do a lot of things a little bit, but doesn't excel at anything. A bicycle computer offers many advantages, especially for advanced cyclists. A phone can serve well as a backup to log your Strava ride as soon as your bike computer's battery dies.