Erratic Power (WATTS) Measurements
About
Spinner®
Chrono
1
™ Power March 16, 2018
In the last few weeks there have been a number of questions about the calibration process
for the Spinner® Chrono™ Power. Here are a few key points about the calibration process.
First thing to remember: The product provides a great balance between minimal service and
accuracy.
The Spinner® Chrono™ Power is calibrated at the factory, and automatically calibrates
thereafter. No calibration task is required at the time of installation or as a periodic operation
performed by the facility staff.
Auto-calibration "AutoCal"
Like any measurement system, the Spinner Chrono Power needs to reset the known zero
point. This is known as zero offset calibration. The Spinner bike will sense when the rider
has stopped pedaling, essentially when the RPMs are at zero. That’s when it will auto-
matically perform this calibration. Customers who want to ensure the best power meas-
urement are advised to turn the resistance to knob fully to left to the off position (zero
resistance) at the end of every ride, and before pedaling begins again. This ensures there is
no torque on the system when the calibration is performed.
Wattage flux:
When a power meter is used for the first time, riders commonly comment that the wattage
measurement “appears jumpy”. This is NORMAL. There are constant deviations in the force
and velocity during every aspect of the rider’s pedal stroke. Given that the power meter
measurement is immediate, instantaneous wattage can appear to be jumpy, especially to
riders accustomed to training with heart rate or RPM, which tends to remain relatively
steady.
Since it is normal to see this fluctuation, it is important to view wattage as more of a target
range rather than a direct aim. In fact, most instructors call out a wattage range for the riders
to aim for. When riders learn to manage their speed and pedal stroke technique along with
appropriate resistance and cadence, variations in wattage measurements will decrease.
Wattage fluctuations are also decreased with proper body alignment on the bike and natural
body movement. Keeping an eye on wattage assists the rider in fine-tuning their riding skills
to develop sound performance on the bike.
Service:
Precor Service Technicians can perform service tests to troubleshoot the system, including
torque, WATTS, RPM, battery and generator voltage and amps, and display elements. If
1
Spinner® Chrono™ Power bike.
Contact Precor Customer Support at [email protected] or 800.786.8404 with
any questions.
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6 Troubleshooting
System Troubleshooting Procedures