How to affect an equipment to an activity ?

No, we can select only one default gear for a main category, and every sub-category will get the same gear.

Automatically Add to...

• Running
• Cycling
• Hiking
• Swimming
• Walking
• Other

So, choosing a default bike for Cycling, will add it to all sub-categories. Mountain and gravel cycling will get the same.

Gears for activities' categories and also sub-categories can be auto changed using a script.

Use in web-browser console (F12).
Set limit=2 as needed, for testing - this will change 2 latest activities if typeKey=mountain_biking.

Change typeKey for other types (gravel_cycling or road_biking), you can also add other search conditions (dates, distances or something), some parameters are listed in this post.

Get gear ID from Gears' page - choose Edit and copy ID from a link. Then replace !!!GEAR_ID!!! by that ID.

Insert if inside a search script (line 8).

jQuery.getJSON(
    'https://connect.garmin.com/modern/proxy/activitylist-service/activities/search/activities?limit=2',
    function(act_list)
    {
        act_list.forEach(
        function(act)
            {

            }
        );
    }
);

if(act['activityType']['typeKey'] === 'mountain_biking')
	{
        fetch('https://connect.garmin.com/modern/proxy/gear-service/gear/link/!!!GEAR_ID!!!/activity/' + act['activityId'],
        {
            'headers': { 'NK': 'NT', 'X-HTTP-Method-Override': 'PUT' },
            'method': 'POST'
        });
        console.dir(act['activityId'], act['activityName'], act['startTimeLocal']);
    }

If you need to remove some gear from an activity, then it's done the same way,
change .../gear/link/... to .../gear/unlink/....

Thanks for your answers. This is something that could be implemented and could be useful. I am sure I am not alone with more than one bike.

Hello,

I have the same needs for bikes and also for running shoes (Trail / Road).

It would be a great addition to implement default gears based on sub-categories instead of categories.