When it comes to interval training, power accuracy is key. Second-guessing your power numbers is no fun. Without reliable power data, training zones become skewed, workouts are less effective and the training experience is hampered. Thankfully it’s super easy to calibrate your trainer. Here’s how you do it.
At Tacx, we produce both wheel-on and direct-drive trainers. Here’s an article that explains the differences, one of which is the calibration procedure. Once calibrated, you can set and forget direct-drive trainers, while wheel-on trainers need regular calibration. Thankfully calibration is a simple procedure that can be completed in minutes. Let’s take a closer look at calibrating both setups.
Wheel-on trainer calibration
The rolling resistance created between the rear tyre and the spindle affects the calibration. Several factors can influence this, such as tyre pressure and ambient temperature. Variations in these parameters over time mean that the trainer can drift out of cal, hence the need for more regular calibration. Here’s a list of steps to follow to successfully calibrate your wheel-on trainer:
- Ensure the tyre pressure is kept as uniform as possible each time you use the trainer. Recommended values are 7 – 8 bar (100 psi – 115 psi).
- Complete a 10 minute warm-up on your trainer to allow the tyre pressure and temperature to stabilise.
- Open the Tacx Utility app* and connect your smart trainer via the Bluetooth connection. Follow the on-screen instructions.
- You’ll be presented with a meter displaying the current rolling resistance (see photo below). You have to adjust the pressure against the tyre to ensure the reading falls within the acceptable green shaded area, neither too tight nor too loose.
- Once complete, the calibration is stored electronically in the trainer and will be recalled each time you turn it on. Future calibrations will overwrite the previous version.
* This free application can be found in the Apple App store and the Google Play store, search for: Tacx Utility app
For maximum accuracy, it’s best to perform the calibration at the beginning of each session. However at a minimum, calibration should be performed each time there is a significant change in any of the variables, e.g. temperature, tyre pressure, or you switch any bike components.
Direct-drive trainer calibration
With direct-drive trainers the calibration process takes seconds. It ranges from a simple spin down procedure, to not necessary at all in the case of our NEO trainers.
Simply open the Tacx Utility App and connect your trainer. It’s important that you’re not pedalling at this moment. Now follow the on-screen instructions. You’ll be asked to spin up to a target speed and then stop pedalling. The trainer will coast down while calculating the required offset for an accurate calibration.
With no rear wheel and associated rolling resistance, direct-drive trainers eliminate many of the issues associated with calibrating wheel-on trainers. Calibration will remain stable so long as there is no significant shift in the conditions. If you have recently moved your trainer, or have left it sitting in direct sunlight then you may want to recalibrate.
In conclusion: Peak accuracy leads to peak performance. Accurately calibrating your smart trainer is the smart thing to do. Consistent power data brings a level of consistency to your training which in turn brings about those improvements every cyclist aims for. So fire up, tune up, and join the indoor training revolution!