A rotor assembly is provided and includes a rotor, tongs and an actuation system. The rotor includes a shaft defining a rotational axis about which the rotor is rotatable and rotor elements supported on the shaft to define grooves. The tongs are disposed in the grooves to occupy and move between first and second positions. At the first positions, the tongs are retracted from the grooves. At the second positions, the tongs are engaged in the grooves to disentangle fibers from the rotor. The actuation system is configured to bias the tongs toward the first positions and is actuatable to drive the tongs into the second positions.