My work has security gates with loop sensors and I never had problems with them opening for my commute bike but when I came to work on my Carbon fiber bike it didn't open so I jumped off and swung my bike horizontal to the ground and just a few inches off the ground and that was enough moving metal to trigger the gate although it might have looked a little funny.
Another intersection that is an exit for the bike path and access to a boat ramp the sensor only works if you go over it quickly but the sensor is right up to the intersection so I have to brake hard to trigger it and still stop before shooting into the intersection. At night the gate is closed so you have to go around the gate line up with the sensor and give a good push-off with one pedal stroke and then hit the brakes.
What ever it takes.