TurbineD, you said, "As rotor speeds continue to increase the starter is disengaged......"
If I may elaborate a little to make it a bit clearer for AF330: The start air valve, which is adjacent to the starter, is closed off during the start cycle (circa 50% N3 on most R-R engines) thus shutting off bleed air to the starter motor. The starter motor shaft continues to rotate as it's driven by the gearbox once the engine is self sufficient and cannot actually be mechanically disengaged (unlike the IDG drive), but pawls within the starter mechanism mean that the starter turbine itself ceases to rotate.