Power dropouts on the trainer

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swdenver
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Joined: Thu Jan 29, 2009 8:39 pm

Power dropouts on the trainer

Post by swdenver »

While riding on the trainer, the iBike Pro wireless unit displays the power consistently. When using the lap counter, I also see
the correct averaged power over that time inteval based on what I was producing. However, when I download the ride and view
it using the iBike software, there are power dropouts (zero power readings) every few seconds, which leads to an incorrect power
average over a time interval. For instance, the iBike unit displayed 280 Watts for a 6 minute interval and after I downloaded the
ride, I can see the power readings at that level, but every 3-5 seconds the power dips to 0 from 280 for a second or two then goes back up to 280 for another 3-5 seconds and continues this. Does anyone know what is occurring and how to stop it?
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racerfern
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Re: Power dropouts on the trainer

Post by racerfern »

I never have power dropouts of any kind with the iBike. I do have dropouts similar to what you describe when the Edge 705 captures the data from the iBike, but that's a known issue. Can you upload a file, I'm curious as to what the other data streams look like.
Fernando
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lorduintah
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Re: Power dropouts on the trainer

Post by lorduintah »

I would check the magnets/sensors for cadence pickup. You may have marginal spacing and the display on the iBike vs. the stored data may somehow get out of synch. What do the speed and cadence plots look like?

I would also do a hard reset on the iBike - flip the battery in the iBike.

Finally - what is your firmware version/software version and computer type (Mac/PC)?

Tom
swdenver
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Re: Power dropouts on the trainer

Post by swdenver »

I have attached my most recent trainer ride. I believe all of the sensors are ok since I don't have this problem on rides
that I do outside. It only shows this behavior for rides on the trainer. Plus, the speed and cadence don't have any dropouts
in the data (and neither does the heart rate). The power is the only thing that has a dropout.
Attachments
iBike_01_19_2010_1621_13_Miles_trainer.csv
(589.88 KiB) Downloaded 418 times
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racerfern
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Re: Power dropouts on the trainer

Post by racerfern »

I'm at work so I can only look at the file through Excel rather than the iBike software, but there are issues with this file.

1) It doesn't look anything like my trainer files. The wind speed is zero for the entire file.

2) The very first minutes show slow speeds and very high wattaage, indicative of not being in trainer mode as the self correcting iBike sets the tilt correction.

3) There are quite a few times when the power drops to zero the speed starts diminishing significantly then picks back up when the power comes on. It appears that your wheel is slipping or possibly jamming from not being on tight enough.

I could swear you're not in trainer mode which of course is necessary. Can you confirm trainer mode is on. It's located under the User Menu and the words TRnR ON are displayed when the unit first comes on.

By the way, if you're not in trainer mode you definitely need to re-do your tilt offset. That's the reason for the exceedingly high power at the beginning of the ride.
Fernando
swdenver
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Re: Power dropouts on the trainer

Post by swdenver »

Fernando.

Thanks for your reply. You are very observant.

When I started my ride on the trainer, I noticed that the power readings were very high when I was lightly pedaling. I
then remembered that I had not set the iBike unit for Trainer Mode On since I was planning on riding outside that day. So
I stopped riding, connected the unit to the computer and using the iBike software, set the Trainer Mode to On. When I got
back on the bike, the trainer mode was active and the power readings were more reasonable. I didn't reset the ride so it just
picked up where it left off. I wasn't concerned since I was going to be doing intervals anyway.

The trainer tension is as tight as I can get it to the tire and I don't feel it slipping (it is usually pretty easy to tell the wheel
is slipping since you tend to get the jerky motion in your pedaling). Also, when I complete each interval, the flashing interval
results show the average power for the interval consistent with what I was expecting.

You mention the wind speed is zero for the entire file. When would the wind be greater than zero for a trainer ride since
you are not moving?

Scott
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racerfern
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Re: Power dropouts on the trainer

Post by racerfern »

Attached is a short trainer ride I did a couple of weeks ago, just for comparison of data. I'm not even sure why I have a copy of this file at work, but here it is. Anyways, you'll see the wind varies on speed and you'll see the slope much closer to zero. I have a feeling you need to do a battery reset on your unit (flip the battery over for a couple of seconds) then insert it correctly. After that, set your date and time be sure to put the unit in trainer mode and try again. I doubt there's anything wrong other than the unit getting confused as to what to do.
Attachments
FM_12_21_2009_1947_13_Miles_KK.csv
(752.08 KiB) Downloaded 406 times
Fernando
swdenver
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Re: Power dropouts on the trainer

Post by swdenver »

i flipped the battery over and rode today in the trainer mode and the ride downloaded successfully. There are no
power dropouts now. Thanks for all the help!!!
fmatus
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Re: Power dropouts on the trainer

Post by fmatus »

I am having a similar issue on an iAero with power dropouts, except the power is not going to 0. It is just diminishing. The power starts out good and then just drops lower and lower until it reads around 100-125 watts, even though it should read 280-300. If I restart the ride the power goes back to normal and then starts to drop again. It does this indoors on trainer mode and outdoors on regular mode. Do I just need to reset it or recalibrate or what?
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racerfern
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Re: Power dropouts on the trainer

Post by racerfern »

fmatus wrote:I am having a similar issue on an iAero with power dropouts, except the power is not going to 0. It is just diminishing. The power starts out good and then just drops lower and lower until it reads around 100-125 watts, even though it should read 280-300. If I restart the ride the power goes back to normal and then starts to drop again. It does this indoors on trainer mode and outdoors on regular mode. Do I just need to reset it or recalibrate or what?
Can you upload an indoor and outdoor ride please?
Fernando
fmatus
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Re: Power dropouts on the trainer

Post by fmatus »

iBike Lindsay_03_23_2012_0000_3_km.csv
indoor file
(17.66 KiB) Downloaded 399 times
indoor file
iBike Lindsay_03_23_2012_0000_3_km.csv
indoor file
(17.66 KiB) Downloaded 399 times
indoor file
iBike Lindsay_03_23_2012_1357_13_km.csv
Outdoor file
(83.9 KiB) Downloaded 391 times
outdoor file
iBike Lindsay_03_23_2012_0001_0_km.csv
indoor file
(29.38 KiB) Downloaded 406 times
indoor file
Here are 3 indoor and 1 outdoor file of diminishing power. Hope this helps.
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racerfern
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Re: Power dropouts on the trainer

Post by racerfern »

As far as the outdoor ride, you're profile numbers seem good with the exception of wind scaling. I can almost guarantee that's part of the issue. Are you sure about your wind scaling?

The indoor ride files are of no help. All the files are flagged as outdoor rides so you never had the trainer mode activated. So... as you ride on the trainer and go faster and faster the wind shows less and less and you get less and less wattage. The trainer mode discards the wind data (you still need to let the iBike do a wind cal at start up) and uses the speed on the trainer/rollers to calculate the wattage.

Double check your settings and let me know what you come up with.
Fernando
fmatus
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Re: Power dropouts on the trainer

Post by fmatus »

The profile for this bike has the wind scaling at .730 on every file I opened at random from May 2011 to now. However on my other bikes the wind scaling is anywhere from .494 to .580. I know the indoor files are not marked as trainer mode, but am sure trainer mode was turned on and checked. Will try that again. And try a reset. I will post results.
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