Same experience. Got my P1's in Spring 2016, and I calibrate before every ride and the offset would always result in single-digit between 4-7. Recently, it is consistently between 26-29. No idea what that means for the pedals.

How fresh are your batteries?

The pedal giving 24N is new, the one giving 45N ha around 45hrs (out of the 60-ish of avg lifetime)

Are your power readings any different? Do you feel you are putting in the same effort as before with the same power output?

---

blog

Can't really says. Not that I can say for sure.
One other funny thing is that, comparing to KICKR, the P1 is measuring less at low/medium power (140-280) but just 4-5W but when going 360W it measures 15-20W more. Also L/R balance looks strange: when P1 measures less, i have more L over 50%, while when P1 measures more, I have the opposite behaviour. But can't say if this is my cycling or the PowerTap :)

Could I ask: is that with KICKR v1 or KICKv2?

My P1s measure 15W less until around 270W when they become roughly equal and stay roughly in line to 400W (which is as high as I go in my current injured state)

Mine did the same thing before the right one completely died. This went on for a couple of months with numbers growing every once in a while.
After it was fixed offset started reading 4-6 again.

What do you mean with "fixed"? Did you send it back to repair?

I'm not really adding to the discussion other than to give further evidence. I had mine read in the singe digits for months, than a jump into the 20's overnight. It has been holding there for a while.

Yes,.

I went through this and you need to send them back to PowerTao for review and, most likely, replacement.

My offset started low an then climbed likes yours and I would see power spikes in the 45000 watt range (I am a fucking monster!) and PowerTap said they knew of the issue and indicated it was the battery caps. So they sent me new coat and batteries but then the spikes increased and my L-R balanced stopped working. I demanded they look a the pedals in person and, well would ya look at that, they replaced everything but the pedal body.

Long story short, your pedals are under warranty and PowerTap needs to have them in their hands for review and service. Don't let them talk you into the battery cap and batteries option. Sen them in.

Bob

Bob,

Questions

I was recently switching some pedals around on the bike, of a client's of my wife's. He had these pedals on his bike - Powertap P1. I had never had these pedals in my hands before or looked at them that closely.

I've heard great things about them as a power measuring device but:

- Wow! These things are heavy. It was a bit of a shock holding these in my hand compared to say, by feathery light Look Carbon Blade2 pedals.

- What is the stack height on these? It seemed high, but that may have been an optical illusion to . .

- The large built-up and bulky area (holding all of the power metering goods) below the pedal - this is all sticking directly out into the wind stream. Again - there's very little sticking out below my Looks (or say the Speedplay pedals) - it all seems more aerodynamic than with the Powertap pedals.

Just curious after a first exposure.

---

---

Steve Fleck @stevefleck | Blog

Steve:

I think when you buy into the P!'s you do so with some of the tradeoffs you mentioned below.

1) Yes, they are heavier than KeO Blades and you need to use the PowerTap cleat but the pedals are so dang easy to move from bike to bike that

2) I did not notice a difference in stack height but I can look into it. I *think* they are comparable to the KeO I was using before I switched. Now that said, when my P1's were being serviced I did noted the weight difference. In order to offset that i ate some more donuts that week.

3) As for the aero-ness of the pedal, I have zero clue and if I am worrying about that I need to eat fewer donuts and train more. Seriously though, I doubt one could measure that since there is no way to control for all conditions.

Also, I have to say that PowerTap customer service is exceptional. When I fell for the battery cap replacement first step I should have insisted they take the pedals but did not. I was quite upset when my data from a 107 mile ride on the IMMD course was corrupted and they understood my mood when I called the next day. I have used the pedals for the last three weeks with zero issues and calibration offsets in the low singe digits.

B

A little more-of-the-same to the above post...
You need to compare the incremental weights of adding an alternative PM to the P1 pedals versus non-PM pedals. Or, compare the weight to a Vector 2. Although the pedals themselves are heavier than standard pedals, some of that would be offset by the incremental weight of an alternative hub or crank power meter.
Stack height is 14mm. It is a little taller than standard pedals, but not way out of line.
I think that is also a valid observation. Though, I have never seen a review that commented on the aerodynamics impacts of P1 pedals versus other alternative power meters. Hubs seem like they would be aero-neutral. But cranks and crank arm PMs would probably have some additional aerodynamic impacts.

The macro things to consider is that the P1 pedals are the easiest to switch between bikes (other than a hub, but the hub does limit wheel options). And, the P1 pedals give you actual L/R power. If switching between bikes is a non-factor, then there are some great crank meters. However, crank meters only estimate L/R power (they do give you accurate total power, which is more important than L/R).

That's true for spider-based power meters, but I'm pretty sure you get true L/R power with dual crank-arm power meters such as Pioneer.

You are right... I just did a broad generalization with spider in mind. The crank arm meters do not seem to have the same degree of popularity as the spider meters. Pioneer, (now) Stages, 4iiii (I think), and a few other specialty makers have dual crank arm with true L/R power.

Mine has climbed from 10 to 30 from April to August.
My bike is stored in an unheated garage, so I attributed it to the increasing temperatures, but I don't know what it is.

Same experience here. Also have this happen with my 2 powertap wheelsets. Calibration number gets further and further out and they need to be sent back to Powertap to be recalibrated or repaired. It's annoying because it costs me the shipping each time and now out of warranty so hesitant to send back.

Ok, thx
well.. being in Europe and having bought it at CleverTraining.uk I don't have the option of sending it for re-calibration but only sending it back to the retailer which is just willing to give me back the money I spent.
Now if I get the money back, not sure I want to buy P1 one again. They are super-convenient when having multiple bikes, but if they only last one year before getting off with the calibration, it's pretty worrying.

It's against the v1 but with latest firmware update and after advanced spindown. Before it was constantly 15W below indeed. Now it is pretty ok.
Apart from when it goes higher where P1 is higher.
You can have a look at a comparison I made:
https://analyze.dcrainmaker.com/...89-52f6-212544114347