Patent ID: 7441841

Claim:
A bicycle wheel rim adapted for retaining a tire and a plurality of spokes thereon, said bicycle wheel rim comprising: an annular rim body having a horizontally disposed rim axis and including left and right annular side walls that are spaced apart from each other and that surround the rim axis, each of said annular side walls having a radial inner edge and a radial outer edge relative to the rim axis, a pair of annular first oblique walls, each of which extends obliquely from a respective one of said annular side walls in radial inward directions relative to the rim axis, and each of which has a first edge connected to said radial inner edge of the respective one of said annular side walls and a second edge opposite to said first edge, said second edges of said first oblique walls being disposed on an imaginary cylindrical plane, a pair of annular second oblique walls, each of which extends obliquely from a respective one of said first oblique walls in radial outward directions relative to the rim axis, and each of which has a first annular edge connected to said second edge of the respective one of said first oblique walls and a second annular edge opposite to said first annular edge, an annular base wall that interconnects said second annular edges of said second oblique walls, that has a radial outer side opposite to the rim axis, that has opposite left and right ends, that cooperates with said second oblique walls to form an arch configuration that opens toward the rim axis, and that is formed with a plurality of spoke fixing holes, and left and right annular connecting walls, said left annular connecting wall extending from said left end of said base wall to connect to said left annular side wall, said right annular connecting wall extending from said right end of said base wall to connect to said right annular side wall, each of said left and right annular connecting walls being disposed radially outward relative to a respective one of said first oblique walls and a respective one of said second oblique walls, and cooperating with a connected one of said annular side walls, the respective one of said first oblique walls, and the respective one of said second oblique walls to define an annular hole; wherein each of said first oblique walls has a radial inner side forming a first angle with said imaginary cylindrical plane that ranges from 15 to 65 degrees.