Inner Clutch Hub. ProX offers a complete line of inner clutch hubs for the Dirtbike and ATV segment. The inner hubs are manufactured by the leading O.E.M. factory in Japan. The die-cast alloy parts are machined to O.E.M. specifications and tolerance to be a direct and cost-efficient O.E.M. replacement. The inner hubs can be used in combination with other ProX clutch components like their hard-anodized clutch baskets, inner hubs, pressure plates and their heavy-duty clutch spring kits or O.E.M. parts. It is no problem to use the ProX inner hub with an O.E.M. basket, plates or any other O.E.M. part.