Closed cell foam articles, such as sports balls, and related manufacturing methods are disclosed herein. The article includes a main body made of closed-cell elastomeric resin foam having a density ranging between about 0.050 sg and about 0.800 sg after curing. Some articles are assembled by inserting a cured core into a main body so that the core is secured in the main body via an interference fit, and the core has one or more portions extending to the exterior surface of the main body such that the an exposed surface of the one or more exposed portions of the core blend substantially with the exterior surface of the main body.