Calibration effect

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Wobblydrow
Posts: 42
Joined: Mon Jul 29, 2019 6:29 am

Calibration effect

Post by Wobblydrow »

Hi

After reading nearly every article in the forum and a lot of your assistance, could you explain what calibration actually does in real terms, given the PP is continually rechecking the mounting angle every 90 seconds? If this is true, and the accelerometer is accurate, what purpose does a calibration perform if you have already set up an uploaded a profile that defines weight, Crr, CDA, type pressure etc?

If a user set a profile and did not do a calibration, does the automatic recalibration every so often make an initial calibration redundant from that point on?
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: Calibration effect

Post by Velocomp »

A calibration ride is a one-time procedure that sets the default values of wind scaling factor (for wind sensor) and riding tilt (for the accelerometer ).

At the beginning of a new ride, it's entirely possible that the angle of the device has changed, particularly if the device was removed between rides.

During a ride, the tilt factor is checked continuously. We do this because it's possible the mount isn't perfectly tight, or that the cyclist shifts weight distribution on the bike such that that the angle of the device on the bike might change slightly.
John Hamann
Wobblydrow
Posts: 42
Joined: Mon Jul 29, 2019 6:29 am

Re: Calibration effect

Post by Wobblydrow »

Thanks for the information

If I have 3 profiles for seperate bikes (all mounted in same position on handlebars) are the following set of numbers acceptable as aero/windscale/friction/tilt, or should I be recalibrating any?

Is their a specific numerical equation that when these numbers are inputted should come out with a constant, or are they truely seperate and non dependant values?

bike 1 0.436 / 1.405 / 27.447 / -3.2%, tyres 50PSI, 32mm tyres, total weight 69.4kg
bike 2 0.478 / 1.541 / 17.731 / -2.0% tyres 80PSI, 25mm tyres, total weight 68.0kg
bike 3 0.488 / 1.574 / 14.731 / -1.6% t yres 80PSI, 25mm tyres, total weight 66.8kg
Velocomp
Velocomp CEO
Posts: 7793
Joined: Fri Jan 11, 2008 8:43 am

Re: Calibration effect

Post by Velocomp »

The parameters are specific to each bike, and measured during the setup and calibration. It is perfectly OK if the numbers are different.
John Hamann
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