The BSA airborne bicycle could be landed in enemy territory in various ways.
By its own parachute. Note that it should land handlebars and seat first as the wheels are very susceptible to damage – as per the photograph from an airborne manual. The BSA drawing for the post-war parabike brochure shows it very dramatically, but it is the wrong way up.
By being carried by a paratrooper. After his parachute had opened, he would lower the bike on about a 20 foot rope. Ideally it would hit the ground first, and he would drift a little bit and land beside it.