DFPM, iaero filter, and sprints
Posted: Wed May 19, 2010 1:23 pm
This entire season I've not had a sprint with a peak power greater than 1000 watts. That's taking into account the cumulative data from my season so far using the iaero and srm with the iaero's filter on. I'm much more diesel than sprinter, so I've been trying to improve my sprint power with some sprint workouts. The greatest benefit my sprint power numbers have seen is turning off the iaero's filter function. The downloaded numbers break a thousand watts with ease. *sigh*
I'd been using the filter since it purportedly is a fix for the wattage spikes the SRM occasionally generates. I've not found this to be the case. Where previously a spike of 2000 watts would show up I see instead the spike rolled into subsequent samples. ie- the samples for power will be 1600, 900, 400, 20. Without the filter it's more like a single corrupt sample.
Does the filter only implement a rolling average or is there some logic in there to look for outlying power spikes? The SRM power spike situation I've noticed is when cadence is zero the first non-zero power sample may be in error. I believe this is more likely to happen if the rider backpedals a bit. It seems like could be better handled in post-processing the file at download instead of filtering the entire data stream in the iaero itself.
I'd been using the filter since it purportedly is a fix for the wattage spikes the SRM occasionally generates. I've not found this to be the case. Where previously a spike of 2000 watts would show up I see instead the spike rolled into subsequent samples. ie- the samples for power will be 1600, 900, 400, 20. Without the filter it's more like a single corrupt sample.
Does the filter only implement a rolling average or is there some logic in there to look for outlying power spikes? The SRM power spike situation I've noticed is when cadence is zero the first non-zero power sample may be in error. I believe this is more likely to happen if the rider backpedals a bit. It seems like could be better handled in post-processing the file at download instead of filtering the entire data stream in the iaero itself.