Back when I got the Cat Eye Padrone Digital cyclocomputer, its bundle comprised of the display unit and the ISC-12 Bluetooth speed and cadence sensor. I didn’t have a dedicated Bluetooth heart rate strap at the time, and so kept relying on the Fitbit Charge 2 for heart rate monitoring.
While the Charge 2 generally works all right for most people and when subjected to casual, everyday use, Fitbit’s LED-based photoplethysmography technology isn’t the snappiest or the most responsive for heart rate tracking, especially under the demands of aerobic exercise such as cycling. If you’re serious about your training, and want as accurate a tracking of heart rate as possible for, say, hitting your training zones, the Charge 2 will tend to have a bit of undesirable lag and/or variance.
To hit two birds with one stone, as the Padrone Digital does accept a Bluetooth-based heart rate monitor strap, I went with Stages Cycling’s unit.
Stages is known more for its crank-arm-based power meters, but it also makes a heart rate monitor that is capable of communicating via either Bluetooth 4.0 Low Energy or ANT+. Bluetooth is by far the more popular short-range device communications protocol among consumer electronics, having started with cellphones and continuing its influence to this day. ANT+, however, is more focused towards fitness tech equipment and cycling gear, and is the preferred protocol for many cycling computers. On paper, at least, this heart rate strap will do the job whichever type of device is on the other end.
The unit is comprised of an adjustable black strap, and the sensor unit itself, which looks like a flat, slightly oval pebble…the kind of shape you’d normally flat-toss into a pond to see how many skips you can get out of it before it sinks. The two are connected via button snaps, which is quite clever. By comparison, the last heart rate monitor I used, a cheap Timex unit with an accompanying watch, had the long plastic sensor directly in contact with my chest’s skin, and hooked at both ends to an elastic strap that held it fast against my person. It was effective, but also rather clunky and primitive.
The pairing process is straightforward on the Cat Eye Cycling app. Turn on the main “Connect” switch, then tap on “Device” from the left-hand menu.
Tapping the “Pair to Device” button will prompt the app to search for new devices. The Stages HR monitor “pebble” has no buttons or controls of any kind, just a gasket-protected twist cover for the CR2032 button-cell battery.
Once the app detects the HR monitor, tap “Pair to Device” again on this dark gray foreground modal.
You should be good to go once the Cat Eye Cycling app displays a new “Heart Rate Sensor” row on its Devices screen.
Now, when you start a session on the Padrone Digital, it will track your heart rate once it picks up the transmissions of the Stages sensor unit. This is shown by a little “H” indicator, next to the “S” and “C” that indicate the computer reading speed and cadence data. The heart rate data itself is shown in a new display field to the left of your cadence.
This brings me to my main complaint with the Stages heart rate strap. In my experience with my particular setup, it’s very easy for the Padrone Digital to lose track of the heart rate data signal when you step away from the bike for more than two meters (7 feet)…and when it does, the success rate for it rediscovering the Stages heart rate strap is pretty variable. I find this very odd, as Bluetooth communication is supposed to be good for a maximum of 10 meters (33 feet). Also, even with the successful pairing, sometimes the Padrone Digital will completely miss seeing the Stages heart rate strap when you start a session.
Perhaps all this is down to the peculiarities of making radio communication work well when strapped against what is essentially a large human-shaped water balloon…and radio signals don’t travel particularly well through water. That said, I would like to know what your experiences have been like with other brands of Bluetooth heart rate straps.
When everything is set up and working well, though, the combination works a treat. As expected, the Stages heart rate strap’s more direct method of taking heart rate trumps the Fitbit Charge 2 in ultimate responsiveness. While they track quite closely and return similar figures in practice, the Charge 2 will under- or over-read by around 3-6 beats per minute at times in short bursts, especially when doing high intensity intervals. It also offers the benefit of not having to look at your wrist, since the heart rate data is right in front of you. I’ve been using the heart rate strap for a few months now, even on outdoor rides, and sweat damage has not been an issue.
Some connectivity weaknesses aside, the Stages heart rate monitor strap makes for a valuable addition to my indoor training setup. This is perhaps as complete of a setup as I can get without dabbling into the rabbit hole of power meters and GPS bike computers.
the accidental randonneur 