A belt module with embedded rollers retained in cavities in the module by retention structure insertable into the module. The rollers and cavities are elongated in the direction of belt travel and closely separated by narrow dividers that form outward-facing surfaces that can serve as bearing surfaces for a belt made of the modules when the rollers are inactivated. When activated, the rollers, which rotate on axles parallel to the direction of belt travel, are supported directly on conveyor rolling surfaces. The dividers also carry the belt tension and stiffen the module.