What is the best sensor and how it relates to delays in measurement.

[steven.renders]

Hi,

I'm new to powerpod v3. Generally very happy.
I did notice that power measurement always seems to be 2 to 3 seconds behind.
Now that I'm watching that. It seems my Tacx Speed and Cadance sensor is also lacking behind.
Probably averaging a few seconds.
Now, I'm interested in a comparison of sensors and how thay relate to delay in power measurement.

[Velocomp]

The sensors we like the best are the Garmin magnet-less sensors.

It sounds like what is going on is that your cadence sensor is delayed in reporting non-zero cadence. This would cause delay in reporting of non-zero power numbers.

[lorduintah]

How about turning off dynamic smoothing, too?

[steven.renders]

Where would I disable this 'dynamic smooting'?

[lorduintah]

You will need to make the change using the Isaac application. You will change the modify the profile that has been installed on the PP.

If you intend to make a change on the PP, you need to attach the PP through the USB cable to your computer.

Run Isaac, goto the Edit Menu and select Edit Profiles...

When the screen pops open, select the Advanced tab on the right.

Near the bottom of the frame is a pop-up labelled Device Power Smoothing.

If the item shows "Dynamic", then by clicking on this you can make other selections from 0 to 30 sec. (The arrows on this indicate there is a choice list that has other values available.)

If you then select one of these, that will be sent to the PP as a modified profile IF you then click SEND to Device and Accept

After you make this change, you can go for a ride and see if anything in the display still behaves as you described. If this does not make any difference, then the delay is in the sensors or bike computer used. I find that when coasting for a bit and then resuming pedaling that Power takes a few seconds to display, which is in line with Dynamic smoothing and the delay to show both Power cvalues as well as Cadence values.

[spangelsaregreat]

Hi,

I have tried both with and without dynamic smoothing. Can't say I notice any difference in the delay in the Power figures still about 2 to 3 seconds. Obviously without the smoothing your power will be a lot more variable.

Regards

[lorduintah]

I am not sure small delays mean a whole lot in the big picture of what kind of power are you generating while on a bike ride. This is not a drag race like with cars and getting off the line is as important as the next quarter mile.

What you sustain for power output and the magnitude of that power output are more indicative of your capability. The only time you are generating any power is while pedaling and if you are pedaling the power will be computed. Another reason for the Normalized Power values - they downplay the periods of coasting.

A couple seconds to see a power value is not something to be concerned with - a LONG delay, however, may indicate a problem with the sensor. I notice an occasional problem with my Garmin cadence sensor in that I can be pedaling at my normal rate and will see (not very often) a temporary drop (not to zero) in the rate - something that quite a few others have seen with these sensors.

What you see on your computer screen while riding and what the PP is collecting as data are also not necessarily 1:1 - which is a good reason to have some kind of smoothing going on.