The Indoor Biker's Workout Buddy

For serious cyclists, winter is indoor training season. Having a way to track your watts, a measure of burned calories, is the only way to make sure you're ready for next spring. Enter the Bkool trainer, which offers pedalers the chance to actively compete against friends and, well, rivals online.

The kit includes several components that all work in tandem. First, there's the trainer itself, which snaps on the rear quick release of your bike and keeps you from accelerating into the wall. The trainer changes resistance level automatically as you pedal. There's also a cadence sensor that helps you measure pedaling intensity, tracking your surges and drifts.

This all taps into your laptop via a USB device. Simply run the free Bsim app in Windows – a Mac version is due next year – and you can create a session based on the location, time, or distance. Want to bring Yosemite to your garage? No problem. The route you pick uses either Google Earth for virtual representation of the actual bike path and surroundings or a video that shows the same thing. You can even load GPS routes you created on a GPS handheld as a GPX file or download them from sites like Strava.

Once you finish a training session, you can share the results (time and distance) on Twitter or Facebook. There's also a multiplayer component where you can race against other cyclists on the same route in real time. It's all a useful, easy-to-understand package.

And about that $650 price: Cycleops makes trainers for as little as $170, so at first blush the Bkool seems pricey. Still, similar computer-enabled trainers typically cost closer to $1,000. Also, the Bsim app is free unless you add a fitness test and extra videos for $15 a month. Overall, it's a good winter deal. [$650; bkool.com]