| 摘要 |
<p>A bicycle crank arm 10 is provided that is a light, highly strong, highly rigid and highly designed in a complex shape. The bicycle crank arm 10 has a crank axle mounting end portion 12, a central crank body portion 14 and a pedal mounting end portion 16. The hollow bicycle crank arm 10 is preferably a one-piece, unitary member that is produced by a tube hydroforming method. The hollow bicycle crank arm 10 has a crank axle attachment part 26 located within the crank axle mounting end portion 12 and a pedal spindle attachment part 36 located within the pedal mounting end portion 16. The mounting end portions 12, 16 have a crank axle hole 24 and a pedal spindle hole 34, respectively, with outside diameters that are smaller than the attachment parts 26, 36, respectively.</p> |
