A rotor includes: a shaft; a core around the shaft; at least one end ring connected to rotor bars that are at least partially enclosed in the core; and means for balancing the end ring around the shaft in a pre-balancing spinning process. A method includes: assembling rotor bars so that they are at least partially enclosed in a core of a rotor; connecting an end ring to ends of the rotor bars; inserting a shaft into the core; step for balancing the end ring around the shaft in a pre-balancing spinning process that involves spinning the rotor; and spinning the rotor in the pre-balancing spinning process.