My hubby just discovered these. Have discovered that there is really no way to attach the old school Garmin sensor to my Seven, thanks to cable placement. And there isn't enough clearance on my crank arm for the cadence magnet, either. This looks like the ideal solution so that I have at least some clue of what I'm doing on the indoor trainer this Winter without buying a cheap rear-wheel computer (which would probably cost about as much as the sensor kit, anyhow). Would love to hear some reviews if anyone has tried this set-up.