Abstract: Provided is a hollow shaft including a hoop layer. The shaft weight is 50 g or less. The shaft has a flexural rigidity EI (N·m2) and a shaft wall thickness t (mm). In a first region having a distance of 200 mm to 300 mm from the tip end, EI/t is 10 or greater and 40 or less. In a second region having a distance of 800 mm to 900 mm from the tip end, EI/t is 45 or greater and 80 or less. The hoop layer includes a partial hoop layer disposed in a part of an entire length of the shaft. The partial hoop layer includes a specific butt hoop layer that is not present in the first region and that is disposed over an entirety of the second region. The specific butt hoop layer has a thickness of 0.05 mm or greater.

Abstract: A golf club includes a club shaft having a first end, a second end, and an inner peripheral surface defining an inner space of the club shaft, and a weight piece installed on a first end side of the club shaft. The weight piece includes an insertion portion located in the inner space, and an engagement portion located outside the club shaft to engage the first end. The insertion portion includes a first portion and a second portion. The first portion has an outer diameter smaller than the first inner diameter. The second portion includes a large diameter portion having an outer diameter larger than the first inner diameter in a state before being placed in the club shaft, and at least one rigidity-lowered portion that elastically deforms the second portion so that the outer diameter of the large diameter portion becomes smaller when receiving an external force.