Recording DFPM data w/o speed

[kylef]

I found myself trying to use my iAero without a speed sensor last weekend (long story on that one). The iAero picked up my SRM's power and cadence fine, but without the speed sensor it was basically useless since it will not record data. I'd like to see the iAero still record data when other inputs are available (specifically when a DFPM is present). I know the speed sensor is extremely integral to the ibike's power computation, but when a DFPM is available the use case can be different.

[Velocomp]

I suppose we could record power vs. time but would the ride file be useful without speed data?

[coachboyd]

It would be. Gustav Larson just had his time trial posted from Tour of California (crazy high numbers!!). He didn't use a speed sensor during the time trial, just paced off of watts. I know some of the other power meters use time of day for recording purposes, so in WKO+ if you stop at the store for a half hour you'll see a black block where there is no data. It will also record total ride time and total time including stops in parenthesis.

[kylef]

CoachBoyd makes an excellent point and it's another one of my pet peeves with the ibike. Data is recorded as ride time, not total duration. So stopping at a stop light, for a coffee, whatever-- it doesn't record the stop interval. This can also give false data in CyclingPeaks by reporting unrealistic data. For (a somewhat contrived) example, say I do 20 minutes on the rivet, get off the bike for any duration, get back on and do another 20 minutes at max power. With the ibike, CyclingPeaks will report 40 minutes at high threshold. The true story is lacking-- was I off the bike for 5 seconds or 5 hours between those efforts? Someone viewing the data may get a false impression of what I can do for 40 minutes, and it can show mis-information in CyclingPeaks's Mean Maximal Power Curve.

Perhaps having an option to just "record any data available" until the user explicitly hits stop/start would do it..? Or record when cadence/power is non-zero? The latter may skip data during coasting, so maybe record data for some time after cadence drops to zero (10-30 seconds?) is a good idea.

[Velocomp]

We'll take these comments under advisement!

[racerfern]

This could be as easy as recording the time of day (TOD) in the csv file. Then you could have a choice of using the time as it is now or the total time which is the TOD from start to finish. Pauses and stops would be automatically recorded in the process.

It could also come in handy when mixing the data with data from another source such as a Garmin 705 that only uses TOD stamps.