Abstract: The present invention generally relates to apparatus and methods for expanding a tubular. In one embodiment, an expander tool includes a body having at least one recess therein. An expansion assembly disposable in the at least one recess includes a piston that outwardly extends from the body in response to a radially outward force. The expansion assembly includes one or more rollers disposed on a shaft such that the rollers rotate at different speeds. In order to improve a rolling ratio, the shaft is arranged on the piston at an outward angle relative to a longitudinal axis of the tool. The expansion assembly is disposed along the tool at a skew to provide tractoring and reduce slippage due to axial movement. A bearing adjacent the roller and rotationally secured to the roller reduces roller heating and wear. In another aspect, methods for expanding a tubular within a wellbore are provided.