Abstract: A shock-absorbing seat stay for a bicycle includes a seat tube coupler having two branches each having a first joint portion, two extended parts each having a second joint portion corresponding to one of the first joint portions, two shock-absorption members made of elastic materials and each held between the corresponsive first and second joint portions, and at least two fastener units. Each of the first joint portions has at least one first through hole. Each of the second joint portions has at least one second through hole. Each of the shock-absorption members includes at least one third through hole. Each of the at least two fastener units is mounted to one set of the at least one first, second, and third through holes to further interconnect the corresponsive first joint portion, second joint portion, and shock-absorption member.

Abstract: A weighting device for use with a racket includes at least one frame strip, at least one weight, and at least one screw. The frame strip is adapted for being mounted on an outer circumference of a racket frame and has a dovetail groove extending along a longitudinal direction thereof, and a plurality of through holes provided at a bottom wall of the dovetail groove. The weight has a threaded through hole and is slidably engaged in the dovetail groove. The screw is threadedly engaged with the threaded through hole of the weight and provided with an end stoppable against the bottom wall of the dovetail groove for holding the weight stationarily. Therefore, the weight can be firmly positioned and the balance of a racket using the weighting device can be quickly adjusted by adjusting the position of the weight.

Abstract: A shock-absorbable bicycle frame includes a tubular member formed of an internal tube and an external tube sleeved onto at least one part of the internal tube. None of any gap is formed between the internal and external tubes. The internal tube is made of fiber reinforced thermosetting plastic. The external tube is made of fiber reinforced thermoplastic plastic. The method of manufacturing the shock-absorbable bicycle frame includes the steps of putting a fiber fabric impregnated with thermoplastic resin into a mold and heating it up to 230-250° C. to form an external tube, and inserting a fiber fabric impregnated with thermosetting resin into the external tube and heating it up to 140-160° C. to form an internal tube inside the external tube. In light of this, the bicycle frame is not only lightweight and preferably shock-absorbable but simple in fabrication with high yield rate.

Abstract: A shock-absorbing seat stay for a bicycle includes a seat tube coupler having two branches each having a first joint portion, two extended parts each having a second joint portion corresponding to one of the first joint portions, two shock-absorption members made of elastic materials and each held between the corresponsive first and second joint portions, and at least two fastener units. Each of the first joint portions has at least one first through hole. Each of the second joint portions has at least one second through hole. Each of the shock-absorption members includes at least one third through hole. Each of the at least two fastener units is mounted to one set of the at least one first, second, and third through holes to further interconnect the corresponsive first joint portion, second joint portion, and shock-absorption member.

Abstract: A racket capable of being changed in its weight includes handle, a main body, at least one nut embedded in the main body, and at least one bolt threadedly engaged with the nut. The main body has a frame and a connection portion connected between the frame and the handle. Because bolts having different weights can be selectively used to be threaded into the nuts, the user can adjust the overall weight of the racket according to his/her need so as to have a suitable racket.

Abstract: A racket includes a main body, a replaceable grip sleeve, a nut and a bolt. The main body has a frame, a handle having at least one hole, and a bridge connected between the frame and the handle. The replaceable grip sleeve is sleeved onto the handle and provided with at least one through hole aimed at the hole of the handle. The bolt is inserted through the through hole of the replaceable grip sleeve and screwingly engaged with the nut disposed in the hole of the handle. The user can replace the replaceable grip sleeve of a predetermined size to meet his/her need.

Abstract: A racket includes a main body, a replaceable grip sleeve, a nut and a bolt. The main body has a frame, a handle having at least one hole, and a bridge connected between the frame and the handle. The replaceable grip sleeve is sleeved onto the handle and provided with at least one through hole aimed at the hole of the handle. The bolt is inserted through the through hole of the replaceable grip sleeve and screwingly engaged with the nut disposed in the hole of the handle. The user can replace the replaceable grip sleeve of a predetermined size to meet his/her need.

Abstract: A racket capable of being changed in its weight includes handle, a main body, at least one nut embedded in the main body, and at least one bolt threadedly engaged with the nut. The main body has a frame and a connection portion connected between the frame and the handle. Because bolts having different weights can be selectively used to be threaded into the nuts, the user can adjust the overall weight of the racket according to his/her need so as to have a suitable racket.

Abstract: A process of making a base of a shock-absorbing front fork for a bicycle, includes the steps of winding pre-pregs around an upper section of each of two cured straight tubes to form a bridge having a foamed core therein, and placing the two straight tubes and the bridge in a mold and heating the mold for curing the bridge such that the bridge and the straight tubes are connected integrally.

Abstract: A base of a shock-absorbing front fork for a bicycle includes two straight tubes and a bridge. The bridge has two ends connected integrally with an upper section of each of the straight tubes. The bridge has a chamber therein. Thus, the base of the shock-absorbing front fork has the advantages of high structural strength and long service life.

Abstract: A base of a shock-absorbing front fork for a bicycle includes two straight tubes and a bridge. The bridge has two ends connected integrally with an upper section of each of the straight tubes. The bridge has a chamber therein. Thus, the base of the shock-absorbing front fork has the advantages of high structural strength and long service life.

Abstract: A front frame for a bicycle includes an upper tube, a lower tube and a head tube all of which are made of fiber reinforced material. The head tube extends integrally from a front end of the upper tube and a front end of the lower tube. The head tube has a chamber communicates with a chamber of the upper tube and a chamber of the lower tube. Two inner tubes are provided in the chamber of the upper tube. The abutted portions of the two inner tubes form a rib such that the structure strength of the upper tube is improved.

Abstract: A front fork for a bicycle includes an upright tube, a fork crown and two branch tubes. The upright tube is mounted on a bottom end of the upright tube. The branch tubes each have a top connected to the fork crown, and a rib located inside an upper section thereof. Thus, the upper sections of the branch tubes have well structural rigidity for increasing the transmission efficiency of the bicycle. The lower sections of the branch tubes have well flexibility for enhancing the rider's riding comfort.

Abstract: An upper frame of a front fork for a bicycle includes an upright tube and two branch tubes. The upright tube has an axial rib. The two branch tubes extend bilaterally from a bottom end of the upright tube and each have an axial rib parallel substantially to a longitudinal direction of the upright tube and a connecting portion located at an end of the branch tube for connection of a fork tube. Thus, the structure strength of the upright tube can be enhanced by the axial rib thereof, and the structure strength of the branch tubes can be enhanced by the axial ribs thereof to bear stress generated from the fork tubes.

Abstract: A seat tube for a bicycle includes an upright tube, a head and an inner tube all of which are made of fiber reinforced material. The upright tube has an inserting portion at a top thereof. The head has an inside chamber and a sleeve portion at a bottom thereof. The sleeve portion of the head is sleeved onto the inserting portion of the upright tube such that the inside chamber of the head is communicated with an inside of the upright tube. An outer wall of the inserting portion of the upright tube is a taper face converging upward. The inner tube is disposed at a junction of the upright tube and the head and interconnected with the upright tube and the head. Thus, the seat tube has strong structure with light weight.

Abstract: A rear frame for a bicycle is disclosed to include two tubes and a connecting portion. The tubes are respectively made of fiber reinforced material and have at least one rib therein. The connecting portion is connected between the tubes. By means of the aforesaid arrangement, the rear frame has a high mechanical strength and light weight.

Abstract: A multifunction racket in which the head frame has multiple elongated slots and ribs positioned in each elongated slot such that the user can selectively insert shock absorbing members of different weights and shock absorbing characteristics into the elongated slots of the head frame to adjust the location of the gravity center and shock absorbing characteristic of the racket.

Abstract: A forming method for fiber reinforced resin includes the following steps. First, put a stack of pre-pregs into a cavity of a die having a plurality of openings in communication with the cavity and the space outside the die. Then heat the die and exhaust air through the openings from the cavity of the die. Thus, the air bubbles between the pre-pregs as well as surplus resin can be drawn out such that the product has improved mechanical strength.