PowerTap freakish peaks

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Hi,
I did my first little test on the inddor trainer with my Powertap Pro today. Trying to figure out my ftp and I did a couple of sprints too just to see what sort of numbers came up. And I got some weird numbers in the middle of a stretch of warm up. In cyclingpeaks the graph shows the watts at around 300watts and the cadence at around 100 but the 5 second peak for the work out is 2047 watts. Looking at the data table shows a 2 second peak of 3089 watts. If I coudl do that I would be world class track sprinter wouldn't I?

So two questions: 1) Is the error in peaks or PowerTap 2) How do I remove the anomaly from cyclingpeaks so that my power profile is accurate?

Cheers

Russell

Hi,
I did my first little test on the inddor trainer with my Powertap Pro today. Trying to figure out my ftp and I did a couple of sprints too just to see what sort of numbers came up. And I got some weird numbers in the middle of a stretch of warm up. In cyclingpeaks the graph shows the watts at around 300watts and the cadence at around 100 but the 5 second peak for the work out is 2047 watts. Looking at the data table shows a 2 second peak of 3089 watts. If I coudl do that I would be world class track sprinter wouldn't I?

So two questions: 1) Is the error in peaks or PowerTap 2) How do I remove the anomaly from cyclingpeaks so that my power profile is accurate?

Cheers

Russell
I see this about once every three or four months, perhaps you were riding near a high power radio/electrical source. The peak shows up on the CPU before I even download and I use the PowerTap software to download. It's easy to edit in cycling peaks 2.0, just select the 123 button and edit the power column numbers by hand.

It's easy to edit in cycling peaks 2.0, just select the 123 button and edit the power column numbers by hand.
Right. From the graph page, click the button at the top with 123 on it to see the values for each point. Then scroll down to the offending points, click on the erroneous value, and type another number right over the top.

but the 5 second peak for the work out is 2047 watts. Looking at the data table shows a 2 second peak of 3089 watts. If I coudl do that I would be world class track sprinter wouldn't I?Shame you didn't get a photo of the PT max watts reading for bragging rights;)

I didn't think CP could handle power numbers greater than 2kW (2048?) anyway due to the wko file format set up to keep memory usage tight?

3kW - man that would be flying:D Sure fire rip the cranks off territory!

You may want to try to download such a ride one more time. The results may vary.

I noticed that in order to get a valid file, the record import pause should always be multiple of 256. If not I end up with garbage data such as the one you describe. Watch for the TSS as well, sometimes it may be n/a. I don't think it's good.

But after multiple downloads, I always get the ride. It's like there's some noise during the connection or something. It's not a tcpip transmission obviously.

Right. From the graph page, click the button at the top with 123 on it to see the values for each point. Then scroll down to the offending points, click on the erroneous value, and type another number right over the top.Thanks for that. I have done it now. The data (and the graph) all around the peaks is around 300 watts with very little variation. The cadence stays the same through the freaky peak and even the graph does not show the peak, it is just the data view and the summary. I have flattened it now and have a more realistic power profile.

It can't have been power lines etc as I was just on the trainer in my kitchen the whole time.

Another thing I noticed is that in a couple of the sprints the PowerTap missed a bunch of data around when I kicked. Now the bike and trainer banged about a bit (like they will when you snap at the start of a sprint) but not loads. Is the PowerTap transmitter super-sensitive to vibration?

Thanks again for your help. I'm just starting out with power training and it is quite a steep curve compared to hrm training.

Russell

It can't have been power lines etc as I was just on the trainer in my kitchen the whole time.

Another thing I noticed is that in a couple of the sprints the PowerTap missed a bunch of data around when I kicked. Now the bike and trainer banged about a bit (like they will when you snap at the start of a sprint) but not loads. Is the PowerTap transmitter super-sensitive to vibration?

Thanks again for your help. I'm just starting out with power training and it is quite a steep curve compared to hrm training.

Russell

Maybe it was the black helicopters going overhead at the time.

One possibility for the dropped data is that some versions of the wiring harness receivers are susceptible to this, latest versions are OK but using soft material on the chain/seatstay to damp the vibrations is usually advised.

I use PowerTap on my cross and MTB and don't see drops that often.

Maybe it was the black helicopters going overhead at the time.

I feel better knowing that they are following you to. I thought I was getting paranoid for a while there.

I feel better knowing that they are following you to. I thought I was getting paranoid for a while there.

Those black copters are piloted by paranoids. They're after me too.