Transcrystallinity in UHMWPE fiber-reinforced HDPE composites promotes a significant beta transition that is untypical of high-density polyethylene. Surface profiling by atomic force microscopy identifies two distinct morphologies in the composite without a boundary phase between them, which coincide with the transcrystalline layer and with the bulk spherulitic matrix. As a result, the claim that attributes this transition to loose chain folds at the lamella surface is favored.