AeroPod, PowerPod and Newton

I have a left-only 4iiii Precision crank DFPM on one bike. It also functions as my cadence sensor for that bike.

- is it possible to pair this with the PowerPod without paying for the Wind Tunnel / CdA add on?
- any other way to get the PP to pick up the cadence automatically?

This isn't critical if it isn't possible, my current workaround is to import a TCX GPS track from Garmin Connect, and I can tick on that to import the cadence data. And that works well enough, usually, and I like to add the GPS track anyway, so it's not any more work then. Just wondering if I could get it to record cadence from the get go.

My other bikes, that don't have DFPMs, I have ANT+ cadence sensors on the left crank instead and they pair/work fine automatically with PowerPod and the files include cadence data.

Unless you want to get the DFPM add-on, your workaround will need to do the trick...

Thanks for that John, the workaround is not a big problem really.

Can I ask- does PowerPod use the cadence data in any way in its algorithm generating the power numbers?

blorg wrote: ↑Thu Oct 25, 2018 6:29 am Thanks for that John, the workaround is not a big problem really.

Can I ask- does PowerPod use the cadence data in any way in its algorithm generating the power numbers?

When cadence = 0 then power = 0. This is the only thing we use the cadence sensor for.

Re: Pairing PowerPod with DFPM for cadence data
by Velocomp » Mon Oct 22, 2018 12:46 am

Unless you want to get the DFPM add-on, your workaround will need to do the trick...

What is the DFPM add-on you mentioned in your comment?

Charcoal007 wrote: ↑Tue Nov 03, 2020 1:11 am Re: Pairing PowerPod with DFPM for cadence data
by Velocomp » Mon Oct 22, 2018 12:46 am

Unless you want to get the DFPM add-on, your workaround will need to do the trick...

What is the DFPM add-on you mentioned in your comment?

https://velocomp-llc.myshopify.com/prod ... pgrade-key

This will add DFPM/cadence reading feature to your PowerPod (even though it says Newton only).

I’m a little confused.

I wasn’t confident of the powerpod calibration so I have purchased a 4iiii left side crank power meter.

I’ve competed one ride and can see that the DFPM results are significantly lower than PP and in fact on a short TT section on my ride with an out and back length of approx 2 kms the PP data shows exactly the same significant wind on both legs and there seemed to be no wind.

The power stroke feature doesn’t seem to be analysing my data.

When I try to check the calibration and force use of the dfpm data I get friction adjustment of -107. I tried to copy that to the profile and Isaac tells me this figure is out of range.



Q1. Does pairing with a DFPM effect the power stroke functionality?
Q2. How can I force pp profile to be calibrated based on dfpm data?

Here are some of the Calibration files I have been using.

I just didn't trust the results and was changing the calibration files.

I have set the combined ride file using a raw calibration file, "Original Calibration Ride 22_07_2019" and it seems to better match the 4iii data.

See attached ride file.

I can't seem top get the PowerStroke Data on this ride file.

Your wind calibration was grossly incorrect (constant headwind).

Here is what I did, using the merged 43KM ride file:

1. I extracted your ride profile "Edit/Edit Profiles/Extract from Ride File"

2. I manually reduced the wind scaling factor (WSF) to about 1.2 (a guess), so that wind speed would be reduced.

3. I used the command "Tools/Switch Profile After the Ride" to see how the reduced WSF would affect overall wind speed. The goal is to get average wind speed to be about the same as average bike speed.

4. After looking at the result I adjusted WSF up a bit, to get wind speed closer to bike speed. The best number is WSF = 1.294. This makes average wind speed exactly the same as average bike speed

With this adjustment, your PP is very close to 4iii; 204W PP vs 207W 4iii.

What's also interesting is the end of your ride, where you go into TT position. PP watts are high, as expected. In fact, for the last portion of your ride, your PP watts were about 50W higher than your 4iii watts; what this means is that you effectively picked up 50W of free power by riding in your TT position!

The other thing you can do, with the Analyze CdA command, is quantify how much more aero you are in the TT position. Your average CdA for the second half of your TT ride is 0.336. This is much better than your default CdA of 0.384.
Modified ride file and profile attached.

Thanks John,

I'll use these settings.

Yes the short TT was a little segment chasing. You are correct I did change my position and tuck down onto the drops on the return leg. I agree I appeared to get more power, but I would say I increased speed with the same power by reducing drag.

I agree PP would see this as an increase in power as it can't change CdA on the fly.

Did you manage to get the power stroke data to work?

When I look at powerstroke it I see the graphic of the pedals rotating but the data fileds for wasted watts has something like NA showing. Previous rides it works fine.

PP interprets your increased speed as a result of increased power. It doesn't "know" you changed ride positions.

The point is that your increased speed is effectively the result of 50W additional power in your usual ride position.

I was unable to get PS to work.

What kind of cadence sensor are you using?

What kind of cadence sensor are you using?

I used to have Garmin crank based unit without a magnet. It was still paired but not active on that ride.
I removed the Garmin crank based cadence sensor as this is now covered by the 4iiii device.
The raw ride data didn't have a cadence signal recorded. When I combined the garmin tcx file with the iride file I added the DFPM and cadence from the 4iiii device.

How does Isaac determine the sensor ID and Type? The ID of the sensors in my profile aren't the same as the ID on my Garmin Edge 820.
How do I remove my Garmin cadence sensor from the profile and replace with my 4iiii?

Here is a screenshot of my powerstroke error.

For PowerStroke you need a separate, crank-mounted cadence sensor.

Cadence data added after the ride won't work.

Velocomp wrote: ↑Mon Nov 09, 2020 10:55 am For PowerStroke you need a separate, crank-mounted cadence sensor.

Cadence data added after the ride won't work.

Thanks John.

I was wondering what is the best setting to use in my profile for Candence sensor in Power Stroke?
I am using the Garmin magnetless candence sensor.

Your cadence sensor should work.

Use above the left chain stay.