Vivoactive 4 and Cadence Sensor

There are no settings for cadence sensor because it simply calculate rotations of your peddles. That part of instruction is specifically for Speed sensor, that's where you need to set the wheel size as from this would depend your speed. So if you are using speed snensor there would be additional menu options like on the image:

If you have just a cadence sensor don't be upset, you will still get the speed data from GPS which should be good in most cases, a speed sensor is mostly necessary if you're using a bicycle indoors.

The purpose of using the Cadence sensor is to know my cadence on an indoor bike. As I'm indoor, the GPS doesn't help me. I need to know my cadence as they tell me to set the cadence of my exercise, which was my reason for purchasing the Cadence sensor.

Cadence sensors don't have any settings because they have nothing to do with wheel size. They attach to your pedal or pedal crank arm and measure the RPM of your pedal speed.

Speed sensors are different and attach to your wheel or wheel hub. They need a wheel size (circumference) setting to convert the counted wheel RPM to speed and distance.

If you want to measure your speed, you will need to get a separate speed sensor or change your cadence sensor to work as a speed sensor (some sensors have this option, some don't) and attach it to your wheel.

I think part of the confusion here is that every sensor IDENTIFIES itself as EITHER a cadence or wheel sensor to the watch via ANT+ or BlueTooth. A cadence sensor cannot be used as a speed sensor or vice versa, unless you can electronically switch the device back and forth between a cadence & speed sensor. But the sensor has to be switched to go back and forth. It cannot do it automatically.

I strongly recommend using both a cadence and speed sensor on your indoor bike so that you can measure cadence, speed, and distance on all indoor bike activities simultaneously.

I don't see the cadence reading anywhere. That's the primary problem. See the update. How do I view the cadence on the watch?

I don't see the cadence reading anywhere. That's the primary problem. See the update. How do I view the cadence on the watch? And I can't use the speed sensor, as the wheel is solid.

When you open the Bike Indoor activity screen, if the cadence sensor has been added and enabled (but not connected), you will see a flashing cadence sensor icon. When it's connected, it will stay on solid. Same thing with the speed sensor.

The way most cadence sensors work is they only activate themselves when they detect movement. So if you start pedaling slowly, it should turn on, and your watch should "connect" to it. It will then say Connected at the top, and it'll start working. Just make sure the sensor is enabled in the sensor settings first.

Also make sure you add Cadence to your data screens. That'll make it easier to see if it's working.

In my experience with several cadence and speed sensors, I found that some of them work well with ANT+, others with Bluetooth, and some with both. You'll need to play around with it to see which connection option works best. When you first try adding the sensor, there should be an option to switch between ANT+ and Bluetooth on the watch. It will only scan one or the other at a time, even though most sensors will broadcast both.