Jumping power values?

[myuce]

On yesterday's ride I was getting power readings that were changing quite quickly and considerably. It would be 150 watts for a moment, than 170, than 130, etc. I don't think I ever noticed that before. I remember reading two possible causes for it: battery or cadence sensor. I checked both and they seemed fine. The cadence was consistent and the battery was showing 2.89 when I was riding. Any feedback from anyone?

Thanks,
Mehmet

[coachboyd]

Can you attach the file to here?
Although power tends to jump around quite a bit when you ride (it's impossible to hold exactly the same power for a long duration). From the jumps you have described, it seems like it would be in line with normal riding conditions. If you were pedaling along at the same effort and seeing spikes greater than 100w (for example, 150, then 320, then 80) that would be something to worry about. But first impression is the small jumps you are seeing are perfectly normal.

[myuce]

Boyd,
I attached the file. No, it wasn't on the order of 100 watts. Maybe it wasn't any different from my other rides, except that when I did 20 min intervals in the past, I remember the numbers being nicely consistent where I was able to work within a plus/minus 5-10 watt range. Anyway, you tell me what you think.
Thanks for taking the time,
Mehmet

[coachboyd]

For the most part the file looks good. There was no profile associated with it though. But everytime I see a jump in your heart rate jump up a little bit it was just a moment after your power went up, so that tells me that it's good.

The one thing that you might want to look at is right at mile 6.3. Did you stop during this ride at all, maybe at a stop sign or red light? If not, what you may want to try is moving the cadence sensor just a little bit closer to the magnet on your crank. All the other times I see the cadence go to a lower number, it was on a downhill, and your heart rate lowers as well. . .telling me you really were coasting.

Overall, I would say you are good to go, and maybe move the cadence sensor a hair closer to the magnet.

[myuce]

Thanks Boyd, I'll do that.

For my own information, I have three more questions:
1.How do I embed a profile to a ride file? When open ride files in iBike2, of course it picks up the correct profile, so I have no problems. I assumed when I send a file out the profile goes with it, but I was obviously wrong.
2. I actually tried to upload the profile as a separate file in addition to the ride file, and every time I clicked on the "Add File" button, it behaved as if it was uploaded, but it wasn't. How does one upload more than one file?
3. When you say look at the mile 6.3, did you get that exact point after opening the file in Excel and looking at it, or is there any other way of moving the cursor in fine increments along the ride to see information at an exact time or distance? I tried to move the cursor using the left and right arrow keys but it doesn't work.

Thanks again,
Mehmet

[travispape]

Thanks Boyd, I'll do that.

For my own information, I have three more questions:
1.How do I embed a profile to a ride file? When open ride files in iBike2, of course it picks up the correct profile, so I have no problems. I assumed when I send a file out the profile goes with it, but I was obviously wrong.

There are 2 actions that cause the profile to be attached to a ride: 1) click the "auto analyze" button and 2) click the "detailed" tab. If you save the file before you do either of those, the profile is not embedded in the file. Since you put the word "_raw" in the file name, maybe you saved the file before doing either of those. All you have to do is save the file again after doing one of those and the profile is there.

2. I actually tried to upload the profile as a separate file in addition to the ride file, and every time I clicked on the "Add File" button, it behaved as if it was uploaded, but it wasn't. How does one upload more than one file?

The forum SW doesn't recognize the *.ibp file type. Try zipping it first.

3. When you say look at the mile 6.3, did you get that exact point after opening the file in Excel and looking at it, or is there any other way of moving the cursor in fine increments along the ride to see information at an exact time or distance? I tried to move the cursor using the left and right arrow keys but it doesn't work.

Thanks again,
Mehmet

You can display distance on the bottom axis by selecting the control near the top-right.

showing distance

distance selector.png (5.16 KiB) Viewed 5759 times

Travis

[coachboyd]

And you can also change that "Full ride" to zoom in on a more specific part of the ride, great for if you want to look at just an interval. That way you can really see how your pacing was for just that section of the ride.

[roadwarrior57]

I sometimes get variable power measurements, especially after I've changed wheels. The problem for me was the distance between my Garmin sensor and the wheel magnet. Moving it closer or further away solves the problem for me.