The present invention relates to a method for manufacturing at least a portion of a sports racquet frame that comprises a step a) of providing a moldable tube structure containing a first inflatable bladder and a second inflatable bladder. The first and second inflatable bladders are positioned on opposite first and second regions of the moldable tube structure. At an intermediate region, the tube structure comprises one or more cross channels, which pass through the moldable tube structure. The method according to the present invention comprises also a further step b) of inserting said tube structure inside a mold forming a mold cavity of a desired shape. Mold members are inserted into the cross channels of the tube structure, so that the outer surface of the mold member faces the inner surface of the corresponding cross channel. The mold members have position and orientation that correspond to the position and orientation, along the string bed plane, of the string port holes, which are to be formed on said frame portion. The method, according to the present invention, comprises also a step c) of pressurizing the first and second bladders, so that the tube structure conforms to the shape of the mold, and heating the mold, so that the tube structure cures. The method, according to the present invention, comprises a further step d) of removing the cured tube structure from the mold cavity and removing the mold members from the cross channels.