bike - Bicycle carrier

Photograph by Noah Scalinon Flickr.
A bicycle carrier, also commonly bike called a bike rack, for transporting bicycles. Bus mounted bike carriers are usually attached to the front of the bus. Automobile mounted bike carriers can be attached to the roof, rear trunk, or rear tow hitch, depending on the vehicle. Bikes may be mounted in the carriers by clamping both wheels and providing bike some additional vertical support, by clamping the rear wheel and the front dropouts (necessitating the removal of the front wheel, which may be mounted separately on blades), or by clamping the top tube (usually in the case of rear hitch mounted carriers).
