Abstract: A seat tube of a bicycle has a tubular body and a tightening block. The tubular body has an insertion hole and a stationary block. The insertion hole is defined in the tubular body and has an inner surface and a tightening recess. The inner surface is formed in the tubular body. The tightening recess is defined in the inner surface. The stationary block is embedded in the tightening recess and has an oblique surface and a fastener hole. The fastener hole is defined in the oblique surface. The tightening block is mounted slidably on the oblique surface and has a tightening surface, a through hole and a fastener. The tightening surface is shaped to correspond to the inner surface. The through hole is defined through the tightening block. The fastener is mounted through the through hole and engages the fastener hole.

Abstract: A holding assembly for a seat of a bicycle has a securing base and an engaging block. The securing base has a connecting segment, an engaging segment, a securing hole and a securing bolt. The connecting segment has a connecting device connected with the seat of the bicycle. The engaging segment is formed on and protrudes from the bottom of the connecting segment and has an engaging recess having an inclined top surface. The securing bolt is slidably and rotatably mounted in the securing hole, extends into the engaging recess and has a threaded portion. The engaging block is moveably mounted in the engaging recess and has an inclined top surface abutting with the inclined top surface of the engaging recess and a threaded portion engaging the threaded portion on the securing bolt.

Abstract: A seat tube of a bicycle has a tubular body and a tightening block. The tubular body has an insertion hole and a stationary block. The insertion hole is defined in the tubular body and has an inner surface and a tightening recess. The inner surface is formed in the tubular body. The tightening recess is defined in the inner surface. The stationary block is embedded in the tightening recess and has an oblique surface and a fastener hole. The fastener hole is defined in the oblique surface. The tightening block is mounted slidably on the oblique surface and has a tightening surface, a through hole and a fastener. The tightening surface is shaped to correspond to the inner surface. The through hole is defined through the tightening block. The fastener is mounted through the through hole and engages the fastener hole.

Abstract: A securing device for a bicycle front fork has a clamping sleeve, an upper pressing base and a lower pressing base. The clamping sleeve is hollow, is made of a resilient material and has a C-shaped cross section. The upper pressing base is attached to a top end of the clamping sleeve and has a threaded hole and an upper pressing surface. The threaded hole is defined in the upper pressing base to screw with a connecting bolt. The upper pressing surface is conical and pressing against the inner surface of the clamping sleeve. The lower pressing base is attached to a bottom end of the clamping sleeve, is connected to the upper pressing base in a thread manner and has a lower pressing surface. The lower pressing surface is conical and presses against the inner surface the clamping sleeve.

Abstract: A holding assembly for a seat of a bicycle has a securing base and an engaging block. The securing base has a connecting segment, an engaging segment, a securing hole and a securing bolt. The connecting segment has a connecting device connected with the seat of the bicycle. The engaging segment is formed on and protrudes from the bottom of the connecting segment and has an engaging recess having an inclined top surface. The securing bolt is slidably and rotatably mounted in the securing hole, extends into the engaging recess and has a threaded portion. The engaging block is moveably mounted in the engaging recess and has an inclined top surface abutting with the inclined top surface of the engaging recess and a threaded portion engaging the threaded portion on the securing bolt.

Abstract: A securing device for a bicycle front fork has a clamping sleeve, an upper pressing base and a lower pressing base. The clamping sleeve is hollow, is made of a resilient material and has a C-shaped cross section. The upper pressing base is attached to a top end of the clamping sleeve and has a threaded hole and an upper pressing surface. The threaded hole is defined in the upper pressing base to screw with a connecting bolt. The upper pressing surface is conical and pressing against the inner surface of the clamping sleeve. The lower pressing base is attached to a bottom end of the clamping sleeve, is connected to the upper pressing base in a thread manner and has a lower pressing surface. The lower pressing surface is conical and presses against the inner surface the clamping sleeve.

Abstract: A derailleur bracket for a derailleur of a bicycle is made of carbon fiber by a computer numerical control lathe and has an upper end, a lower end, a front side, two sidewalls, an upper through hole, a lower through hole and a mounting recess. The upper through hole is formed through the sidewalls of the derailleur bracket in the upper end. The lower hole is formed through the sidewalls of the derailleur bracket in the lower end. The mounting recess is formed in the front side of the derailleur bracket.

Abstract: A kettle holder includes an elongated plate adapted to be mounted on a bicycle frame, a holding arm integrally extending from one side of the elongated plate to be vertical to a longitudinal axis of the elongated plate for engagement with one side of a kettle and a helix arm integrally extending from the other side of the elongated plate to be opposite to the holding arm. The helix arm has a bend formed on a free end thereof so that a receiving space is defined among the holding arm, the helix arm and the bend for receiving therein the kettle. The helix arm is able to deform to provide clamping force for engagement with the kettle and when the kettle is removed, the helix arm returns to its original position.