Cycling may be the most geek-friendly activity out there. You can find more gadget options here than in any other category, but we suggest focusing on the basics. A good way to start is to choose a cycling computer (with a heart-rate monitor), a cycling website, an indoor trainer, and, if you can afford it, a power meter.
The best options
Your cycling computer is the single most essential piece of cycling tech, for the roads or the trails. A dedicated computer is easier to read than a smartphone, can include barometric pressure for better altitude, and lets you avoid killing your smartphone's batteries (helpful on those days when you flat out one too many times and need to call for a ride). Aside from keeping tabs on your speed limit, a cycling computer can track your distance and location (even more important when riding compared to running), and it can pair with heart-rate or power sensors to improve your training.
Skip the old wired models and go with a wireless, GPS-enabled unit such as the venerable Garmin Edge 500 or the Magellan Switch Up watch. If you also run, many GPS watches (especially from Garmin, Polar, and Suunto) will work for cycling too; bike mounts for these watches are widely available (and will keep your hands on the handlebars). Most models use simple maps that will display only where you've been, so step up to a Garmin Edge 810 if you want full maps. The Garmin Edge 510 and 810 can connect with your phone over Bluetooth and piggyback on the data connection to send out live updates and automatically upload your workout.
The Magellan Switch Up is another option.
If you have the cash, and if you ride roads, get a direct-force power meter. While a heart-rate sensor tells you the effect your ride has on your body, a power meter directly measures your output using a strain gauge (and isn't affected by lack of sleep or too much coffee). A power meter is also valuable since it measures your output regardless of speed, allowing you to maintain the right effort on hills or flats. Studies show that training with a power meter improves fitness faster than using a heart-rate monitor alone. Although Bluetooth LE is starting to appear, most such units use ANT+ and can therefore connect with far more cycling computers.
The Stages Power Meter, which uses a modified crank arm with a strain gauge, starts at $699, but it may be less accurate than other models since it measures only one side of your pedaling (unless you buy two). CycleOps sells a range of hub-based PowerTap meters that integrate into your wheel, while SRM and SRAM are crank-based systems starting at over $1000. Pedal-based meters are hitting the market, with the Polar Keo available now and the Garmin Vector arriving later in the year. These items are easy to swap between bikes, and measure left/right power balance--but they command a premium price and are definitely for early adopters (as they are difficult to find right now).
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