What activity to choose with Garmin when riding halfbike?

At present I chose Bikes but I have a feeling it burn more energy than riding bike.... is there anyway we can customize the activity closer to reality?

We don't have any experience with Garmin's settings, but it may be a good idea to ask the Halfbikers from our Strava club. You can find our club here > www.strava.com/clubs/halfbike