PowerPod recalibrating during rides

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Parallelfish
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Joined: Fri Aug 18, 2017 10:34 pm

PowerPod recalibrating during rides

Post by Parallelfish »

I have sporadic instances of the PowerPod recalibrating at the beginning of rides. Power readings will be extremely high or extremely low (like zero) until the recalibration is complete. When I do an "analyze calibration" after the ride, a new tilt value is suggested. This is despite the fact that no changes have been made to the PowerPod between rides (same calibration file and not remounted). This happens every two or three rides.

Attached is the files from the calibration ride, and a sample ride with zero power values at beginning of ride:
Jules_2017_09_15_1102_3_Miles_CalRide.csv
Cal ride
(54.67 KiB) Downloaded 192 times
Jules_2017_10_13_1021_17_Miles_HiDef.csv
Sample ride file
(337.75 KiB) Downloaded 173 times
BBQcyclist
Posts: 49
Joined: Mon Apr 10, 2017 8:38 pm

Re: PowerPod recalibrating during rides

Post by BBQcyclist »

Perhaps unrelated to your issue but Ive had similar recalibrations occur at beginning of a ride twice this summer.
It may have been because I pressed on the PP "on" button for too long at the beginning of my 2 rides...but I'm not sure.
Just like your scenario - wattage was all over the map but after a while, settled down and stabilized.
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Thanks, but not the issue here. The button was depressed and immediatly released.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Please post .ibr ride files
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Velocomp wrote:Please post .ibr ride files
Well, that was my intention. Clearly I got into the wrong folder.
Jules_2017_09_15_1102_3_Miles_CalRide.ibr
Jules calibration
(93 KiB) Downloaded 238 times
Jules_2017_10_13_1021_17_Miles_HiDef.ibr
Jules sample ride
(503.88 KiB) Downloaded 240 times
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

I took a look at your "hidden" data in the ride file. For some reason your slope factor was way out of whack at the beginning of this ride. After 8 minutes it settled in to the correct value.

The "correct" value is memorized at the end of each ride, and used as the starting point for the next ride.

If you aren't removing your PP between rides, and your PP is attached tightly so that it can't rotate on the mount, then I don't see any reason this should happen.
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Velocomp wrote:The "correct" value is memorized at the end of each ride, and used as the starting point for the next ride.

If you aren't removing your PP between rides, and your PP is attached tightly so that it can't rotate on the mount, then I don't see any reason this should happen.
This is happening pretty consistently, every two or three rides. Initially I was removing the PowerPod after each ride and swapping between bikes. I was very careful regarding remounting each time, so was puzzled with the varied results. To eliminate that possible variable I have left the PowerPod mounted, untouched, for several weeks. The issue persists - a couple of rides with consistent readings, beginning of next ride does the recalculation, and the following ride will be back to normal (returns to the same value as the calibration ride).

Have experienced the same behavior with the other bike I have used the PowerPod on.
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Here is the most extreme example from another bike:
Seymour_2017_08_18_0053_3_Miles_CalRide.ibr
Seymour calibration
(89.42 KiB) Downloaded 185 times
Seymour_2017_08_18_0053_3_Miles_CalRide.ibr
Seymour ride file
(89.42 KiB) Downloaded 182 times
Seymour_2017_09_02_0625_17_Miles_HiDef.ibr
Seymor ride file - return to normal
(488.81 KiB) Downloaded 176 times
This sequence of files show the calibration, a ride were recalibration occurred, and the following ride where things returned to normal. PowerPod remained mounted to the bike, unchanged, during the sequence.

I have experienced this behavior from the beginning. Performed multiple calibration rides, thinking some corruption must have occurred to the calibration file, always with the same results. Like I have indicated above, eventually left PowerPod mounted to the bike for each sequence to ensure the mount was constant.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Two of the three files are identical.

Please post two consecutive ride files where this problem occurred. It is important that the PP was NOT removed from the bike between the rides.
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Sorry about that. Here is the file I intended.
Seymour_2017_08_26_0629_17_Miles_HiDef.ibr
(497.52 KiB) Downloaded 238 times
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

The two examples submitted are the worst cases. In the case of Jules, calibration resulted in a tilt value of -0.7. Each time I did a calibration resulted in this same tilt value. Successive rides following the last calibration resulted in the following values:

-0.6
-0.7
-0.6
-0.8
-0.7
-0.8
-0.7
-0.7
1.4
-0.6

The unit has not been moved since the calibration ride. A large number of rides commence with the unit recalibrating, with values hovering around 400 watts, or zero watts, when I would expect something in the range of 70 -90 watts.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Please post two consecutive files in the same post. I don't want to be analyzing the wrong thing... :-)
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Three consecutive rides:
Julrs_2017_10_08_0735_17_Miles_HiDef.ibr
Oct 08
(488.25 KiB) Downloaded 229 times
Jules_2017_10_13_1021_17_Miles_HiDef.ibr
Oct 13
(503.88 KiB) Downloaded 235 times
Jules_2017_10_15_0650_17_Miles_HiDef.ibr
Oct 15
(508.39 KiB) Downloaded 237 times
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Your 10/8 ride begins with a "normal" value of tilt but recalibrates itself to a much different number in the first 8 minutes.

The 10/13 ride starts with the memorized value of tilt from the end of the 10/8 ride, and in the first 8 minutes returns to the normal value from the beginning of the 10/8 ride. So, it would appear that your PP was returned to its original position sometime between the end of the 10/8 ride and the beginning of the 10/13 ride.

The 10/15 ride starts with the value from the end of the 10/13 ride (which is the "normal" value), so the first 8 minutes of your 10/15 ride is fine, and the end value is normal, too.

I would keep a watch on things, but it appears that your PP is working correctly.
John Hamann
Parallelfish
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Joined: Fri Aug 18, 2017 10:34 pm

Re: PowerPod recalibrating during rides

Post by Parallelfish »

Yesterday’s ride was normal, but still a mystery as to why I receive varying tilt values when the unit has not been moved from the bike.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Parallelfish wrote:Yesterday’s ride was normal, but still a mystery as to why I receive varying tilt values when the unit has not been moved from the bike.
Make sure your PP is firmly attached to the mount and cannot rotate.
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

The mount is firm and has not rotated. If it had rotated, I would not expect it to give an off reading, and then recover on the following ride.

I have struggled with this issue from the beginning. I deburred the edges of the mount, and used an awl to line up the the holes in the unit and the mount to ensure the mount screw engaged freely each time the unit was mounted. Always made sure that the unit was firmly rotated against the stop prior to tightening the screw.

Each time the unit went into recalibration I verified the mount had not moved. Then I would follow up with another calibration ride - always resulting in the same -0.7 tilt value. The ride following the recalibration always matched the calibration values. Then one ride would be off, and the next back to normal. Then maybe a ride giving a tilt value in the other direction. I could find no pattern or reason.

The past month I decided to leave the unit mounted, untouched, for the duration of testing to eliminate the mounting as a variable. The inconsistant results have continued. I believe that I have eliminated the mounting as an issue.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

It sounds like you are doing all the right things.

Make sure that, once your ride ends, that you don't allow the speed sensor/wheel to generate signals through "false" rotations (such as putting your bike on a bike rack, where the wheel can spin). That could provide false readings to the tilt sensor.
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Now this is an interesting twist. My usual routine is to hook the unit to a computer to download ride data before wheeling the bike to the garage and hanging it by the saddle on a rafter. So the data will have been collected prior to any additional wheel movement. Occasionally I immediately wheel the bike to the garage and hang it, and collect the ride data after the next ride. So yes, in these cases there is wheel movement following a ride, as well as possible wheel movement as the bike is being hung at a severe angle. But the latter case is rare enough (maybe twice) that I am not sure it accounts for what I am seeing. Perhaps those were the two times that I saw very large deviations. Certainly something to account for in my future observations.

So, if I follow your thought correctly, even though I have "ended" the ride on the cycle computer, the PowerPod is unaware that the ride has ended and is still recording for another twenty minutes. If so, appears that a Velcro strap may be in order.
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Yup, PP will stay awake until the speed wheel has been motionless for 20 minutes.
John Hamann
BBQcyclist
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Re: PowerPod recalibrating during rides

Post by BBQcyclist »

Velocomp, in that case perhaps PP would definitely benefit from a simple "off" button - when you design a future version.

(Otherwise, it's a bit like Hotel California ' where you can enter - but you can only leave after 20 minutes of being motionless)
;)
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

Yeah, we are thinking about this...
John Hamann
GooseRider
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Re: PowerPod recalibrating during rides

Post by GooseRider »

or maybe double tap on button to turn off ...
BBQcyclist
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Re: PowerPod recalibrating during rides

Post by BBQcyclist »

@gooserider: Doubletapping the same button may inevitably lead to accidental on/offs...or entering calibration modes...and frustrated customers. Too much to ask frm 1 button...and us feeble minded customers, myself included! ;)
musomaniac
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Re: PowerPod recalibrating during rides

Post by musomaniac »

could the on /off function be achieved via a firmware update ?
Velocomp
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Re: PowerPod recalibrating during rides

Post by Velocomp »

musomaniac wrote:could the on /off function be achieved via a firmware update ?
Yes, we are looking at this.
John Hamann
Parallelfish
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Re: PowerPod recalibrating during rides

Post by Parallelfish »

Velocomp wrote:
musomaniac wrote:could the on /off function be achieved via a firmware update ?
Yes, we are looking at this.
That would be excellent!
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