Did a ride today. Here is the set up… Zwift/ Neo controlled by the P1 pedals. The Garmin recording the P1 data along with on screen Zwift.
The ride was basically 6x6 @ 170. I hit lap after every interval to record the avg power for each one.
Power was anywhere from 157-160 for each one on the Garmin.
I don’t really understand how it could be so off considering the P1’s are controlling the Neo. I zeroed the pedals on the Garmin before the ride, I don’t see any way to calibrate the pedals in Zwift.
I don’t remember this occurring to this degree using Trainerroad and my SRM. The pedals have only been on the bike temporarily while the SRM was out being calibrated.
Here is the ride below. This is what Zwift recorded. Zwift shows avg power was 166-167 (goal was 170) for each interval.
You should download both files and look at the power output recorded by the Garmin compared to the power output recorded by Zwift. My guess is you’re seeing dropouts in the signal recorded by the Garmin since the avg power is lower.
If you use Golden Cheetah you can overlay both power traces on top of one another and it should be fairly clear if they match.
Thanks!!Those plots look like they’re coming from Training Peaks which smooths the data. The slider in the upper left changes the smoothing function but I don’t know if it’s possible to turn it off completely. The smoothing filter will tend to ‘hide’ zeros or dropouts. If it’s possible to post the .fit files I could look at the raw data.
Sorry I guess I’m stumped. The graph below is from one of the intervals. The Zwift data is more variable but I don’t know if that’s being generated by the Neo or from the pedals. What happens with higher power intervals? Do you see the same offset or a similar %?
Sorry I guess I’m stumped. The graph below is from one of the intervals. The Zwift data is more variable but I don’t know if that’s being generated by the Neo or from the pedals. What happens with higher power intervals? Do you see the same offset or a similar %?
I’ll do some higher wattage intervals tomorrow. Thanks for looking into it…
The PowerTap P1 are dual ANT+/Bluetooth Smart. But they’re not quite the same in the way they pair… The ANT+ power broadcast comes from the master pedal (left) and has both L/R power data. If you’re pairing your P1 to Zwift via ANT+, that’s what it’ll see.
The Bluetooth on the other hand is independent. If you pair your P1 to Zwift using Bluetooth then it’ll only be able to pair one (it can only pair one power meter device at a time), and it’ll double the value. Effectively becoming a P1S. Think Stages, 4iiii, single sided units.
So the scenario where this is totally possible is when pairing Zwift via Bluetooth Smart to the P1, and your Garmin pairs to them via ANT+, and there’s some wonky/imbalance/over/under/estimation/differences.
If both Zwift and your Garmin unit are pairing to the P1 via ANT+, then the raw data should match up 1:1 assuming no dropouts. If you want to dive into that deeper, grab both FIT files (Zwift saves them in /documents/zwift/activities) and head over to Ray’s Analyser. https://analyze.dcrainmaker.com/
The PowerTap P1 are dual ANT+/Bluetooth Smart. But they’re not quite the same in the way they pair… The ANT+ power broadcast comes from the master pedal (left) and has both L/R power data. If you’re pairing your P1 to Zwift via ANT+, that’s what it’ll see.
The Bluetooth on the other hand is independent. If you pair your P1 to Zwift using Bluetooth then it’ll only be able to pair one (it can only pair one power meter device at a time), and it’ll double the value. Effectively becoming a P1S. Think Stages, 4iiii, single sided units.
So the scenario where this is totally possible is when pairing Zwift via Bluetooth Smart to the P1, and your Garmin pairs to them via ANT+, and there’s some wonky/imbalance/over/under/estimation/differences.
If both Zwift and your Garmin unit are pairing to the P1 via ANT+, then the raw data should match up 1:1 assuming no dropouts. If you want to dive into that deeper, grab both FIT files (Zwift saves them in /documents/zwift/activities) and head over to Ray’s Analyser. https://analyze.dcrainmaker.com/
I think you may be on to something… I’m pretty sure the pedals are pairing with Zwift via BT, and the Garmin via ANT+.
I will check later…
It’s interesting actually… I noticed that when Zwift paired for power it was using the L pedal. For cadence it was using the R pedal.
It’s interesting actually… I noticed that when Zwift paired for power it was using the L pedal. For cadence it was using the R pedal.
Yep, that’s Bluetooth then. One-to-one connection and once paired it’ll disappear from ‘advertising’. That’s why one will be power, the other cadence when selecting devices in Zwift.
It’s interesting actually… I noticed that when Zwift paired for power it was using the L pedal. For cadence it was using the R pedal.
Yep, that’s Bluetooth then. One-to-one connection and once paired it’ll disappear from ‘advertising’. That’s why one will be power, the other cadence when selecting devices in Zwift.
So once power is paired via ANT+ … the numbers should match up???
Had the very same thing with TrainerRoad. P1’s, Garmin 520 and a Cycleops Hammer. TrainerRoad was giving me a TSS/IF value and my garmin was putting out something quite different. Swapped the P1’s to Ant + and it all now matches pretty much to the exact TSS.
Surprising that the discrepancy between BT and ANT + was so great.
You probably have a L/R power balance of 53%/47%. This would cause doubling of the left to equal 170W while the actual total power was only 160W.
