The Draw: Complete and Total Silence
There’s simply no trainer as quiet as the Stac Zero, nor anything you’ve ever seen quite like it. When you mount your bike to the trainer, you’ll wonder exactly how it’s going to provide resistance, since the wheel simply floats freely as opposed to sitting atop a roller. Middle school science class magnets are the answer: The trainer uses the metal in your wheel rims to provide resistance against a set of magnets as you pedal without ever touching (carbon rims are a firm no-go). Instead, they form an invisible forcefield that lets you throw down wattage without making a peep, assuming your drivetrain is at least half-way clean. And the ‘Power’ variant of the Stac Zero will even accurately report your current wattage, broadcasting it on ANT+ and Bluetooth Smart.
Review by Ray Maker