Pedaling technique in trainerview via garmin vector
920 views
Skip to first unread message
Bart Coddens
Dec 30, 2014, 12:59:11 PM12/30/14
to golden-che...@googlegroups.com
Dear all,
My Garmin Vector pedals are able to record two metrics:
Torque Effectiveness and Pedal Smoothness.
Garmin describes this as follows:
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.
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.
Garmin has added this info to the FIT SDK:
I saw today that Garmin has released another update:
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
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.
Could it be possible to include this data in realtime in trainingview ? In my opinion this could be really helpful for pedalling technique training/exercises.
Best Regards,
Bart Coddens
Jörn R.
Jan 3, 2015, 1:24:36 PM1/3/15
to golden-che...@googlegroups.com
Hi Bart,
I just updated my Vector's to the latest firmware and purchased an Edge 1000 - since my previous Edge 500 does not get an update for all
the new stuff any more. 510/810 seem to be updated - but I made a good deal for the 1000 (late X-Mas present :-).
Used it on my trainer today - quite interesting data. I discussed with Mark this morning and will start adding TE/PS to the Trainer view.
The new cycling dynamics is very interesting as well - but might need more time to be added - not much documented yet - partly ANT private.
Not sure yet what the effort is to get it to work. Just wanted to let you know.
Is case someone else is also looking into that area or may have already started - please let me know to align the work.
Joern
Damien Grauser
Jan 3, 2015, 2:04:33 PM1/3/15
to Jörn R., golden-cheetah-users
Dear Jörn,
I have added the new metrics in the fit parser and in json format.
I will be ready to commit before the end of the weekend.
Damien
--
_______________________________________________
Golden-Cheetah-Users mailing list
golden-che...@googlegroups.com
http://groups.google.com/group/golden-cheetah-users?hl=en
---
You received this message because you are subscribed to the Google Groups "golden-cheetah-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to golden-cheetah-u...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
Reply all
Reply to author
Forward
0 new messages