Every GPS bike computer can track your route and measure the speed and distance of your ride. The Polar M450 ($188 at Amazon) and the Garmin Edge 25 are two of our favorites for beginners. You could even use your phone and an app like Strava or MapMyRide to achieve this.
But if you're serious about biking, you need to consider the Garmin Edge 520. It's got a ton of features high-end riders would like, such as tracking functional threshold power (the maximum power you can sustain for an hour), estimating your VO2 Max and providing recommendations on how long it will take your body to recover from a ride. They definitely matter for me.
Other performance-oriented features include the ability to connect to Shimano Di2 electronic shifters and record gear changes, as well as integration with Strava to show on-device Segments in real time. There's also support for ANT+ to pair with accessories (including Garmin's Vector power pedals and rear-view radar system), as well as ANT+ FE-C, which allows the 520 to control smart bike trainers. In short, the Edge 520 allows a lot of flexibility with accessories, although it won't work with Bluetooth heart-rate monitors.
The Edge 520 is comparable to the Wahoo Element, but Garmin managed to squeeze all of these features into a more compact design. And the 520 is available now for $299, £250 or AU$450, which is $30 less than the Element. This is why it's my go-to pick for most riders.
The Edge 520 has everything beginners and competitive riders would look for in a bike computer. There's GPS, GLONASS (a GPS equivalent that adds more coverage) and a barometric altimeter to track your route and measure speed, distance and altitude, but that's only scratching the surface. The 520 is so feature packed, it's actually easier to start this review by highlighting what the device is missing.
It doesn't include Wi-Fi or a touchscreen display, which can be helpful for syncing and navigating the interface, but are otherwise two features I can live without. The big omission is the lack of turn-by-turn directions, which means you can't use the 520 like you would with Google Maps on your phone or a GPS system in your car. You can, however, import a route to the device and receive some basic navigation to help you stay on course. For full navigation, you'll have to upgrade to the Edge 820 or Edge 1000.