"Outlier" PowerTap data

[J-V]

Do any of you ever get errant ('outlier', in statistics) data from your PowerTap hubs? I just had the flywheel replaced on my 300PT (due to a wobble that couldn't be rectified), and during today's first ride (my second monthly test!), I got one data point of 2400+ watts in the middle of my 20-min test.

How common is this? Is it indicative of a certain problem that all of you familiar with PowerTaps might know about?

I'd really rather deal with this sooner than later if it needs to be replaced, as it's heavily skewing my autmatically-grabbed data, needless to say...

Thanks in advance for the input!

J\V

 

[Alex Simmons]

Not sure.

With 3 PT hubs over a couple of years I've only seen one such outlier and I wasn't riding at the time. Just some strange thing that happened one morning when I put the CPU into the cradle.

If it's a frequent event, I think I'd be calling Saris.

 

[objective]

I've seen this a couple of times. Really wanted to believe what I was seeing too. ;-)

 

[Steve_B]

Do any of you ever get errant ('outlier', in statistics) data from your PowerTap hubs?

Maybe once or twice I've gotten some crazy-high number, e.g., 1800 Watts for one reading (one second) in the middle of a 10 minute period where I was just noodling along. I just deleted it from the file. I presume that it came from some radio interference in the area.

 

[Woofer]

Do any of you ever get errant ('outlier', in statistics) data from your PowerTap hubs? I just had the flywheel replaced on my 300PT (due to a wobble that couldn't be rectified), and during today's first ride (my second monthly test!), I got one data point of 2400+ watts in the middle of my 20-min test.

How common is this? Is it indicative of a certain problem that all of you familiar with PowerTaps might know about?

I'd really rather deal with this sooner than later if it needs to be replaced, as it's heavily skewing my autmatically-grabbed data, needless to say...

Thanks in advance for the input!

J\V

This happened to me on the first ride with a new wheel a couple of times. Not sure if I was in the same place geographically or just a coincidence with happening on first ride.

 

[J-V]

This happened to me on the first ride with a new wheel a couple of times. Not sure if I was in the same place geographically or just a coincidence with happening on first ride.

Thanks for the responses.

This happened indoors on my trainer, just like every other time I've ridden it, so doubt in my case it's any kind of radio interference. Hopefully it won't happen again, but I'm left to wonder how much of this is 'too much'?

 

[Steve_B]

This happened indoors on my trainer, just like every other time I've ridden it, so doubt in my case it's any kind of radio interference.

Ummm...I don't.

When I say "radio interference" that's a generalized term, not just meaning it originates from a radio. I'm speaking of anything that interfere with the Power Tap receiving the correct signal or produce a false signal.

It can come from electric motors, electric generators (like car alternators), electric heaters (toasters, blankets, cooking devices), microwave ovens, furnaces, car door opener transmitters and receivers, cell phones, cordless telephones, laptops equiped with wireless internet, ham radio transmitters, even dissimilar metals like copper and aluminum making contact can produce it. Many of these are around the average home.

They don't have to produce consistent interference to be at fault. All the above produce random interference from time to time.

edit - also a police car, fire truck or ambulance could have been going by your house at the time with it's transmitter on. There are many possibilities.

 

[peterwright]

We saw this with some PT300's we were using in the studio - it went away when we stopped downloading directly into CP and instead downloaded into Power Agent and then dragged the data file into CP.

http://www2.cyclingpeakssoftware.co...start=15&sid=c985f7df95622e44f505e0dd4d1d07f2

The above link might also help you.

 

[J-V]

We saw this with some PT300's we were using in the studio - it went away when we stopped downloading directly into CP and instead downloaded into Power Agent and then dragged the data file into CP.

http://www2.cyclingpeakssoftware.co...start=15&sid=c985f7df95622e44f505e0dd4d1d07f2

The above link might also help you.

Thanks for the links, checked it out, but I'm downloading directly into PA7. In about 500 'miles' of using the 300PT I hadn't seen a single errant piece of data until getting the new flywheel. Hopefully it was an aberration and won't recur.

Thanks for all the input!

-J\V