If you've caught the smart trainer bug, you know you had two choices when deciding on a smart trainer: The kind where your back wheel is removed and the bike connects directly to the trainer, or the kind where your back wheel rolls against the cylinder to create resistance. The latter option is referred to as a wheel-on trainer. The power reading in watts that are created by the wheel-on option are much more finicky than the fixed option.As you can imagine, your tire pressure and how hard you screw the trainer against the tire can impact the relative difficulty of turning the flywheel from one workout to another. For this reason, if you read the fine print in your smart trainer manual, you'll see you should do a spin-down calibration before each ride to make sure you are seeing accurate wattage.This is a pain, and it's annoying, but the other option is to think you are an awesome superstar for two weeks only to recalibrate and find that you are actually not that great of a cyclist.We recommend using the spindown calibration from the manufacturer of your trainer. For example, the Kickr Snap wheel-on trainer has a Wahoo Utility smartphone app that takes you through the calibration spindown. I make a habit of doing this at the beginning of each ride. Wahoo does not recommend warming up for 10 minutes first, although other manufacturers do. In addition to simply completing it until you see the green checkmark, read the instructions and look at the results of the spindown. If they are outside the normal parameters, you can tighten or loosen the trainer against your tire to ensure accurate results.
If your trainer is not calibrated correctly and you are using a smart trainer program such as Zwift, your hills will be too hard or not hard enough; your wattage-based interval workouts will not give you the expected training challenge; and your comparison to others riding with you virtually will not be accurate.
Owner at Beginner Triathlete, web marketing consultant at SiteInSight, writer, entrepreneur, advocate for unstructured nature play for kids.