An apparatus of a damper for a bicycle comprising a housing defining a chamber, and a piston, movable in the chamber along a first direction. Additionally, the relatively low-temperature solution-based processing achievable with the methods of the present invention permit the use of plastics in the fabricated devices. The operator protective structure includes a front guide provided with a top bar and a bottom bar and installed up and down in front of the cabin to protect the cabin from objects penetrating into a front of the cabin and a top guide formed long on a ceiling of the cabin in a front and rear direction to protect the cabin from falling objects.