The STAC Zero is a unique trainer, being one of the quietest, smallest and easiest-to-use power-compatible trainers available. Using a set of powerful specially arrayed magnets to induce eddy currents in the wheel rim as it passes through, the trainer creates a slowing-down of the wheel, which you feel as resistance.
With its zero-contact resistance unit, there is no noise and no tire wear. The trainer itself is completely silent, which is ideal for riders who live in an apartment with neighbours below. The only noises generated in a training session are from the bike’s drivetrain and the rider’s suffering. During the test (also nap-time), my baby remained fast asleep.
The only downside to this technology is that it will not work with a carbon wheel. Since the tire does not contact the trainer, a trainer tire is no longer required. I was able to leave my cyclocross tires on my ‘cross bike, making the transition from indoor to outdoor riding a breeze. There was no need to swap tires or wheels.
Where the STAC Zero really stands out is in size and weight. Without a bulky flywheel or resistance unit, the STAC Zero folds completely flat. When stowed, the STAC Zero is only three inches tall, and can easily fit into checked baggage or even a large backpack as well as be effortlessly stashed under a bed for out-of-sight storage, making it a perfect trainer option for pre-race warm-ups. Weather can turn cold and nasty, especially in cyclocross season, and the STAC Zero is the perfect tool for those late-fall ‘cross race warm-ups under a tent in front of a space heater. The trainer is the lightest one tested, making it very easy to move about.
Available in basic or power-equipped models, the power-meter model is both Bluetooth- and ANT+-compatible, so it is able to transmit to a standard head unit or a computer with such software as TrainerRoad or Zwift. The SRP is $589.99.