Weird behavior with Powertap P1 Pedals

power-meter

#23

@ErickVH

No problems per say. Never noticed issues until I compared power output.

Connecting my P1 to TR via BLE and at the same time connecting my P1 to my Garmin gives you a big power output. specially if you have imbalances


#24

Yeah the low battery warning comes in plenty of time. To me the cost savings of milking the last % from the battery isn’t worth any sort of hassle so I just swap them on a schedule to avoid it


#25

@trpnhntr How many hours do you put on the pedals a month? And, are you using lithium?


#26

Yes I use lithium batteries. I ride between 40-60 hours a month depending on the time of year - the pedals are rated at 60 hours so I find this leaves me in a pretty good spot most of the time


#27

That explains it. I change batteries a lot less- I’m on the low volume plan.

@ecloaiza I’ll have to see if I see a big difference tomorrow between TR via BLE and my Elemnt via ANT.


#28

It is quite common for L/R balance to change over the power curve, which can definitely affect consistency of measurement if you are using single-sided power (as you effectively are over BLE). If you are ‘just’ getting through a SS effort, that means you ARE getting training effect, regardless of what the “numbers” say. And your FTP likely hasn’t “plummeted” in reality.


#29

I am not sure which workouts you are referring to, I am using BT and my Kickr now tracking my P1’s outside of TR and abandoning powermatch. Second workout today with this set up without issue.


#30

Great.


#31

If I get through a SS effort at VO2 max effort/HR then I inevitably don’t make it through the next one or I can’t do the following days workouts at the prescribed intensity. Even if I can fight through somewhat for a few workouts, it’s not sustainable. I end up missing workouts, having to modify the intensity or end up sick. Over a surprisingly short period of time you begin losing fitness.

Use whatever word you like - my FTP dropped over 20% throughout the course of these issues.

Eliminating power match appears to be the solution in my case. Hopefully the fitness returns quickly. Whatever the issue is technically, I don’t know. Perhaps it’s my specific equipment, however neither Wahoo nor Powertap have located any issues yet. I suppose I don’t care at this point if I have in fact identified the issue - I just wish I didn’t have to track the P1’s separately. I really will only do that for future FTP tests to know the discrepancy when I head outdoors. Otherwise I’ll just stick to the Kickr on TR moving forward.


#32

I use P1S so one sided, I’ve just been having problems with signal cutting out that I think was low battery. TR had reported it with 72% just last week, had no warning yesterday at all as the signal kept disappearing. Just checked the battery and it’s showing empty.


#33

@ecloaiza So I did my ride today with TR (iPhone) and my Elemnt. The P1’s were connected to the Elemnt via ANT and TR via BLE. TR was consistently higher about 10w as you said.


#34

@bsoneill

Wow!!. Like I said earlier, my last two workouts using with ANT+ felt more difficult. Good thing I have my FTP test in two days. Based on this discovery I don’t expect a HIGHER FTP.

I will continue to use just ANT+ because I want that consistency outdoors vs indoors


#35

I’ll run my bolt along side TR and see what happens. Maybe I’ll pair my Garmin to the Kickr power and see what it’s doing as well.


#36

Curious if you find any issues/discrepancies. It very well could be a one-off issue for me. Tracking it down to the specific cause has been tough, however so far removing powermatch and going back to the Kickr have cured it thus far.

*my Kickr is the V2, I believe 2017 version - not sure which one you are running.


#37

Well… god damn it. The ESD problem they were talking about in DCRainmakers video just bricked my kicker. No speed data.


#38

I’m having some low watts for my (bought used) P1. Here’s screenshot of one 10 min SST effort. P1´s reported 10w lower power than my Neo and P2M NG. Cadence was spot on. Zero´d both PM twice during ride. Same difference. I’m :exploding_head:


#39

Depending on where that 10w difference was recorded, it’s not that far outside the stated margins of error between the devices. Has this only occurred on one ride or been pretty consistent across multiple workouts?

Did you make sure the P1’s have the latest updates from Powertap installed?


#40

I don’t think this is exactly correct. If you look at this post on the Powertap support site it explains the situation
slightly differently than the way I interpreted your response.

As I read the Powertap explanation, the BLE option doesn’t double the left leg; it transmits and pairs each pedal independently over BLE and then relies on the receiving device to either combine the two values or - if the receiving unit can’t pair with two power meter devices at once - double the single value it’s receiving.

In other words, its not the pedals that are the “problem”, but rather the head unit or other receiving device.

Admittedly, that seems like a cop out on Powertap’s part, since they admit in the post that most units can’t do the former and imply they aren’t designed to do the latter.


#41

Correct. I need to revise my statement as the essence is there, but the detail is off.


#42

I am truly nitpicking; your original post was functionally right and useful.

I just panicked when I read it b/c I ordered a pair of P1’s yesterday, didn’t have any idea about the variation in transmission source functionality, and immediately did a deep re-dive of research to find out if I’d made an expensive mistake.