Doby

Technically a joist or truss is not the same as a beam but for you purpose it will work fine to hang a bike.

A joist or truss is 1 1/2 inches thick so to mount your hook you must find the exact center. This is hard to do with tapping, if you cannot get a stud finder and you are good at patching 3 small holes in drywall then tap till you locate or get close to the joist. Then use a 4 penny finish nail to find the center, this should result in 3 small holes witch can be filled with "one time spackle compound" and touched up with paint