The Edge 520 Bike Computer, Garmin's latest addition to the head unit game, expands on the functionality of the Edge 510 with the ability to display metrics encompassing everything from charting fitness levels to power output and targeted recovery. It's also the first head unit to feature a live connection to Strava, which means you can track segments in real time from the saddle. As you might expect, it features all of the standard functions included in the lower-numbered Edge models, but the key changes mentioned above are what recommend the Edge 520 as a personal guide to the extreme edge of endurance training.
With the advent of the 520, Strava is now a constant presence on our rides. We like the 510's Garmin Connect segments, but let's face it: when it comes to informal K/QOM competitions, Strava's the real battle ground. The 520's direct connection to Strava gives you an edge in that battle because the segments update live as you ride, simultaneously displaying the stats of your present performance against the current K/QOM and your own personal record. In addition to just being a lot of fun, live Strava connectivity also provides more structure to training and race-prep by keeping us constantly linked to an external referent, allowing for data-parsing and adjustments on the rides themselves, not just in between them.
The list of parse-able, power-related metrics has also expanded compared to the 510, so the data nerds get as much of a win as the Strava junkies. For us, the big star here is that, when paired with Garmin's Vector or Vector 2 power meter pedals, the 520 calculates your functional threshold power (FTP). Once equipped with an FTP, you'll be able to calculate ideally timed and measured efforts for intervals tailored to your own fitness level. Instead of burning out trying to hit arbitrary output numbers, knowing your FTP helps you stay at a level that's more effective for increasing your present level of fitness. After all, the real point of intervals isn't punishment; it's improving. The Edge 520/Vector combo makes that improvement even more efficient.
When it's paired with any other ANT+-compatible power meter and heart rate monitor, the Edge 520 still provides VO2 max estimates and recovery time guides, which set it apart from every other head unit in Garmin's line. While the former is obviously useful in planning and executing a training regimen, the latter helps to maintain focus on an often neglected part of training: the negative space between workouts. Maximizing recovery is almost as important as maximizing the efficiency of your time in the saddle. Until recently, virtually all of the training apps and devices also ignored this period, focusing exclusively on the activity portion of training. This feature is just one more way the Edge 520 keeps you focused on improving your form, even if that improvement involves low-key recovery.
In addition to the above new shininess, the Edge 520 also includes all of the functionality of the 510. It's compatible with Shimano's D-Fly Data Management system, effectively replacing the PRO Scio ANT+ head unit, and also works with ANT+ turbo trainers. It performs all the basic computer functions speed, trip time, trip distance, odometer and the GPS and GLONASS compatibility keeps you located no matter where your ride takes you. It automatically uploads to Garmin Connect, syncs with smart phones for notifications, and displays weather information so you're never out of the loop or surprised by changing conditions mid-ride.