This is very similar to the previous request to select gear by activity. I would like to take it a step further and have the option to select gear based on sensors. I have 5 bikes that I ride regularly and 3 of those bikes use multiple wheel sets. Since every bike has its own cadence sensor and each wheel set has its own speed sensor, Garmin Connect should be able to associate the appropriate gear with these sensors.
An example of how I would like to see it operate is like this: I select MTB on my 820 and it already knows to associate my default mountain bike with this activity (not just default bike like it does now). When I upload the activity (or maybe on the Garmin Device) it will see that I used MTB #2 and wheel set #3 instead of the default bike based on the sensors that are active during that activity.