Abstract: A hub for a blade having a central axis rotatably mountable on a shaft including three or more blade supporting arms for supporting a blade, the hub having a leeward side facing a supporting tower and a windward side facing the opposite direction, wherein the side arm includes a pair of composite load bearing spar caps with uniaxial fibres extending from the radially outermost extremity of the hub, past the shaft with one of the pair on each side of the shaft, across an adjacent arm and terminating at the far side of the arm, and on the windward side, a second pair of composite load bearing spar caps with uniaxial fibres extending continuously from the radially outermost extremity of the hub, past the shaft, with one of the second pair on each side of the shaft, across an adjacent arm and terminating on the far side of the arm.