PowerTap Pro Cadence Options

cbjesseeNH said:

I have always been a bit confused by the PowerTap Pro candence options for use with the cadence sensor. The options are Default - Hub then Pedal, Pedal, Hub.

I see the PowerTap SL options include a default - Pedal then Hub, which makes sense, as should the sensor fail the cadence is calculated from the hub.

But what is Hub then Pedal for the PTPro? If the hub fails, then the pedal is used? But it seems if the hub fails, there is no data at all. I don't get it.

BRET

The data sources for pedal and hub are independent of one another. The main differences between the choices (not saying they matter to you, but just what they are): (1) hub cadence maxes out lower than pedal cadence -- 150rpm vs. 200rpm IIRC; (2) if the hub sends bad data, it affects everything -- watts, speed, cadence; (3) pedal only cadence has a lag vs. the hub, so if you have stopped pedaling for any reason (e.g., corner in a crit) it takes a second or two for the cadence to be displayed after you start pedaling again. For these reasons, I choose pedal, then hub.

Thanks. Elsewhere, someone has referred me to:

"Page 21 of the manual. The "Hub-PEDAL" mode is the default cadence mode and the Pro head calculates cadence from the pedal/crank sensor first as long as it receives a valid signal. If no signal is detected from the cadence sensor on crank, then it will revert to using the hub mode for calculating cadence."

This is not in my print or the online PTPro pdf manual, that I can find. In fact, my print manual refers to cadence display in the 20-240 range and the online pdf in 40-140 and 40-130 range. That's some confusing documentation. One has to wonder what the firmware actually does ...