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  • Cycling Dynamics, Torque Effectiveness (TE) and Pedal Smoothness (PS)

    With the release of Vector 2.70 Garmin introduced Cycling Dynamics.

    Cycling dynamics data will be sent to head units that support the collection and display of this new information from a Vector dual sensing system.
    (Note. Vector S will not send cycling dynamics data unless it is upgraded to a dual sensing system)

    In this first release of cycling dynamics the following information has been added.


    • Add calculation and output of Cycling Dynamics, Power Phase.
    • Add calculation and output of Cycling Dynamics, Peak Power Phase.
    • Add calculation and output of Cycling Dynamics, Platform Center Offset (PCO).



    This release is available via the use of the Vector Updater.

    In order to collect and view cycling dynamics data you will need a cycling computer (head unit) that supports it.
    The units that currently support cycling dynamics are the:-

    • Edge 1000 software build 2.70 or higher
    • Edge 810 software build 3.40 or higher
    • Edge 510 software build 3.40 or higher



    These 3 Edge software builds are being released on 2014-12-30 and can be obtained using Garmin Express or the Web updater.

    Power Phase - This is the period in the crank rotation when you are producing power (positive torque). It is reported for both the left and right sides using a start and end angle.

    Peak Power Phase - This is the angular range where you are producing a specified fraction of the total power for a crank rotation. It is reported for both the left and right sides using a start and end angle. By default the fraction is set to 50%.
    This peak power fraction setting can currently be adjusted via the Edge 1000 if desired.

    Platform Center Offset (PCO) - This is where on the pedal platform the force is being applied and is reported for both the left and right sides. The center of the pedal platform is zero (0). Forces applied inboard of the center line are reported as negative, while those that occur outboard of the center line are reported as positive. The PCO is reported in millimeters.


    Coordinate system - The angular data reported by cycling dynamics uses the following reference points
    • Top Dead Center (TDC) is zero (0) degrees
    • Crank forward and horizontal, 3 o'clock position, is 90 degrees
    • Bottom Dead Center (BDC) is 180 degrees
    • Crank rear horizontal, 9 o'clock position, is 270 degrees.
    Last edited by Vector-Info; 04-29-2015, 05:12 PM.

  • #2
    Where will the Cycling Dynamics data show up

    They will show in the ride history on the device as well as on Garmin Connect.

    If you want to see them in real-time then you will need to configure one or more of your training pages to show the cycling dynamics data fields.

    There is a new data field category called "Cycling Dynamics" that contains the following data fields.


    • PCO
    • PCO - Avg.
    • PCO - Lap






    • Power Phase - L Pk. Avg
    • Power Phase - L Pk. Lap
    • Power Phase - L
    • Power Phase - L. Avg.
    • Power Phase - L. Lap
    • Power Phase - L. Peak






    • Power Phase - R Pk. Avg
    • Power Phase - R Pk. Lap
    • Power Phase - R
    • Power Phase - R. Avg.
    • Power Phase - R. Lap
    • Power Phase - R. Peak




    Seated and standing time data fields have been added in Vector software build 3.500.

    Reporting of position transition
    Vector will not report a change in position that has a short duration so if you quickly stand up and then sit down again it will ignore that change. Any change in position that lasts for more than 5 seconds will be reported. The 5 seconds before the report in position change will be added to the appropriate timer.


    • Time Seated
    • Time Seated Lap
    • Time Standing
    • Time Standing Lap




    In addition to these data fields that are available on the 1000, 810 and 510 (the names may vary a little) the 1000 has a cycling dynamics data page that graphically shows the stop and end angles for the power phase and peak fraction as well as the position of the force on the pedal platform.

    This page is off by default. The control for this is under the activity profiles "Data Screens", "Cycling Dynamics" On/Off.




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    • #3
      Torque Effectiveness (TE) and Pedal Smoothness (PS)

      In the Vector software release 2.40, Vector transmits two new power metrics. In addition to power (watts) and power balance (left/right % contribution), this release now also transmits Torque Effectiveness (TE) and Pedal Smoothness (PS).

      These metrics are defined in the ANT+ Device Profile - Bicycle Power rev 4.0.

      Compatible head units will be able to display TE and PS in real-time. This data will also be recorded to the FIT activity file, allowing the TE and PS values to be displayed in the ride history on the head unit and uploaded to power analysis tools.

      Below we address several questions about these two new power metrics.


      • How are they calculated?
      • Can I achieving 100% and what does that mean?
      • Should I be trying to achieve 100%?



      Torque Effectiveness (TE)

      How is it calculated?
      Torque Effectiveness is calculated for each crank arm based on the positive (forward) and negative (backward) torque applied to the crank over each revolution. The diagram below shows a typical power curve for one crank arm, where P+ represents the positive power applied to the crank and is the sum of the instantaneous power measurements. Similarly, P- is the sum of the negative instantaneous power measurements. P- is typically produced when the crank on the backstroke side is helping lift that leg as the rider is pushing down on the other side crank.



      Torque Effectiveness = (((P+) + (P-))/(P+)) X 100

      Can I achieve 100%, and what does that mean?
      Yes, it is possible to achieve a TE value of 100% for both the left and right side.
      If you achieve 100%, it means that during that crank revolution you did not accumulate any negative power measurements (P-). You were able to either fully unload the pedal on the backstroke, or you were able to produce a positive driving torque for the complete revolution.

      Should I be trying to achieve 100%?
      Though it is quite achievable to hit 100% for periods during a ride, we are not providing specific guidance at this time on how this metric should be used to modify your riding or training behavior. We are enabling the collection of this metric with Vector and compatible Edge devices in order to allow athletes, coaches, and sports scientists to assess performance and potentially develop training programs.
      Based upon our testing, TE values typically fall in the 60%-100% range.


      Pedal Smoothness (PS)

      How is it calculated?
      The Pedal Smoothness metric is calculated on each side by dividing the average power (Pavg) by the peak power (Pmax) across one crank cycle (see the diagram below). It is a measurement of how evenly power was applied throughout all 360 degrees of a pedal stroke.
      The shape of the power curve and the resulting value of Pedal Smoothness will vary depending on the style of pedaling.



      Pedal Smoothness = (Pavg/Pmax) X 100

      Can I achieve 100% and what does that mean?
      It is extremely unlikely that a rider could achieve a value of 100%. To achieve 100%, a rider must produce exactly the same power output throughout all 360 degrees of a crank revolution. Based upon our testing, PS values typically fall in the 10%-40% range.


      Should I be trying to achieve 100%?
      As with TE, we are adding the PS metric in order to enable the athlete, coaching, and sports science communities to explore performance and training methods utilizing this new data.
      Attached Files
      Last edited by Vector-Info; 04-29-2015, 08:17 PM.

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