The bike tag covers gay material where a bicycle or motorbike figures into the situation — as a prop, a mode of transport, or part of the outdoor or garage setting. The word alone says something about the surroundings, not about the men involved or what happens between them. Related vocabulary you may run into nearby includes terms like hunk, smooth or uncut, which describe physical traits, and bareback, which refers to sex without a condom rather than a separate act. Those words work on a different level than a setting term like this one.