Using PowerPod with Xert

[the shovel]

I'm trying a subscription to Xert online training app to see if it can improve my training.

I've had trouble with my PowerPod positioning as long as I've owned it. From time to time, it doesn't get positioned exactly as it was on the previous ride, and when this happens, the first ~ 8 minutes sometimes has to be trimmed from the .fit file from my Garmin or it makes me look like Superman, with a 300 watt FTP instead of my Clark Kent-like 225w. (The new firmware update should reduce that to ~ 90 seconds, but the file will still have to be trimmed. Even 90 seconds of 1500 Watts will render the Xert data useless. See below for more on positioning the PowerPod.)

I was wondering if there's some other sequence I could use at the start of the ride, especially now that the re-calibration will take place in 90 seconds.

If, for example, I get my sensors and the PowerPod all linked up to my Garmin 1000 edge, but don't press "start" on the Garmin for the first 90 seconds of a ride, will the PowerPod recalibrate itself during this period to eliminate any stray high power readings? Or does the PowerPod not recalibrate until the Garmin "start ride" button is pushed?

Positioning the PowerPod
This is a suggestion rather than a question, and I don't need a response. You can use it as you see fit or ignore it if this isn't a problem for most PowerPod owners.

I've mounted my PowerPod on three different mounts. The worst was the Go Pro handlebar mount. It was more difficult to get it in exactly the same position each time. The best has been the K combo mount that has my Garmin on top and the PowerPod underneath. I've had to tighten the PowerPod on with a screw driver to get it really solid, but have found that by taking care to position it exactly the same each time, and tightening it well, I've eliminated ~ 90% of the "recalibration" sequences at the start of my rides.

This is one aspect of the PowerPod to bike mounting issues that requires extra care when using Xert. Otherwise, I've just ignored the first few minutes of my rides, but when the Xert algorithm uses this data, it makes the Xert data misleading - even worse than useless.

If the tabs on the PowerPod were a precision fit with the mounting bracket, this problem would likely be eliminated. But I find the Go Pro mounts and the PowerPod mounting tabs allow far too much rotation, and the instructions to "press forward on the PowerPod" don't help because the mounting seems to be sensitive to how much one presses forward. Precision in the PowerPod mount could fix that all that. If many will use Xert, or if people have other reasons to want their ride files uncontaminated by extraneous readings in the first few minutes, this could be a worthwhile area of improvement.

[Velocomp]

Yes, if you wait 2 minutes before turning your Garmin on, that will eliminate any potential calibration issues.

Be aware that EVERY PM requires calibration, and unless it is done correctly, prior to riding, then those numbers will be suspect, too!

I understand your point about the mount. As you note, there are different tolerances for different mounts. If we were to adjust the tab height on PP, so that it would fit tightly against our mount, it would not fit at all with the K-Edge mount.

We will look to see if we can adjust our mount spec slightly.

[the shovel]

I'll try this today. It should be fairly easy and painless. I keep my bike in a locked bike room in the basement parkade of our condo. I could simply ride around in the parkade for 2 minutes with the Garmin on, end the ride after two minutes, and discard the Garmin file for the ride. Then out the garage door and onto the road for the "real" ride.

[flahutewannabe]

The recent firmware update reducing the positioning re-calibration from 8 minutes to 90 seconds is a huge improvement.

I may be missing something, but my Garmin is set to start recording at the press of a button, not when I turn on the unit. My approach with the new firmware is to wake up sensors, turn on the PPod, turn on the Garmin, start riding, then after about 2 minutes hit the Garmin start button to begin recording. The ride .fit file should begin then after the PPod is transmitting calibrated data.

Is there something in this that wouldn't work well for you?

BTW, I don't have an Xert account (thinking of it) but am using their "What's my FTP?" app. What a great tool to get an accurate FTP without having to go through an 8 or 20 minute sufferfest (lower case so no TM infringement )

[Velocomp]

Your procedure will work just fine with your Garmin. Just wait 2 mins before pressing the start button (by the way: though it is a good thing for you, I hate that particular feature of the Garmin!).

I've heard some others say interesting things about Xert FTP app. I could have used it 6 years ago, when we were developing our Dash+Power. We were field testing our Fitness Test, and I had to do a pile of FTP rides. I accused the firmware developer of abuse

[GooseRider]

I used PowerPod with Xert. It worked quite well. Only suggestion is to make sure no cables can touch the PowerPod, can result in unrealistic peak power. Other than that my PowerPod derived Xert profile aligned quite well with my DFPM Xert profile.

Thanks,

Morten

PS I love Xert. I stopped subscribing to Trainingpeaks.

[the shovel]

I have Xert on a trial subscription. Still haven't decided whether or not to subscribe.

I cleaned up my Garmin ride files from this year using FitFile Tools to cut sections with inaccurate power readings in the first few minutes. I then reposted all of them to Xert. Now, the FTP readings and Max Power are comparable with what I see in my PowerPod data. The problem of odd readings at the start of rides has pretty well been eliminated by using the K-Edge dual mount and doing one leisurely circle of my block before pressing "start ride" on my Garmin. I appreciate your note about cables touching the PowerPod - had thought the same.

The reduction in re-calibration time to ~ 90 seconds is really useful. In a few cases, I exported files out of PowerPod - thanks to John for that tip. They seem to be more reliable than Garmin files. My Garmin run out of power last year for the last hour of a 6 hour ride, but PowerPod recorded it - I think faithfully, because the power and speed readings look as weak and slow as I felt.

There's a lot of data available in Xert, but I haven't fully figured out how to use a lot of it yet. It looks as though it would be more useful with a trainer than road riding. But I have figured out in looking at my ride files on Xert that I 've been riding too hard on recovery days, and not hard enough on training days. That is a really useful learning that you can only get from experience. A friend who's done several Iron Mans has essentially said the same thing, but there's a difference between someone telling you, and having data from your own rides to tell you where you went hard enough and where you slacked off.

There's a great little circuit up the hill from my house that takes about 5 minutes to climb, then loops around back to the bottom in about the same time. Virtually no traffic, and a great view. Looks perfect for hill repeats to increase 5 minute power. I'm planning to try it when Xert tells me I'm "fresh".

[GooseRider]

Install the various ConnectIQ data fields on your Garmin. TTE TTR, MPA POW, Bio shift cadence, I use those when I race.

Morten

[GooseRider]

Also the Xert FTP app. I love Xert. It my main software now.

[the shovel]

Update on using Xert with my PowerPod.

First, the need to trim power spikes from the start of some rides continues. I put shims into my K-Edge Garmin/PowerPod over/under mount to reduce the potential for misalignment. It's very tight now, very little potential for changing the tilt of the PowerPod in the mount. Yet it still gets odd readings at the start of some rides, and they throw Xert analysis off unless the ride files are trimmed to remove them. It's a little extra work, but it does make the data more "real".

I added the Xert fields to my Garmin, and they provide direct feedback on not just the power reading, but how it compares to FTP and maximum power. You can tell at a glance when you're creating a new breakthrough that will increase your FTP number. I'm not sure if that's the same as increasing your FTP, though.

I'm gradually trimming off the power spikes at the start of rides on which the PowerPod tilt changed between mountings, and uploading them to Xert. It gives me a great record of my fitness and the effectiveness of past training. I think this will help me make the best use of my training time.