Disc brake rotors are fastened with either a six bolt interface or a lock ring (with either an internal spine or external notches). The most common method on modern road bikes is the lock ring. Typically the rotor will be secured with a lock ring with external notches for a thru axel, and a lock ring with an internal spine where you have quick release skewers. My own road bike uses both and this is my experience of removal and replacement. For professional advice please refer to this video from Park Tools
If you have the correct tools removing the disc takes seconds. You should use protective gloves so as not to contaminate the disc surface, but apart from that it’s as straight forward as unscrewing a bolt.
Should you decide not to use a torque wrench when replacing the discs, then make sure it is firmly secured!!
Center Lock Ring with External Notch
The tools required are a torque wrench (or ratchet wrench) and a bottom bracket tool 44mm. For this purpose I use a Park Tool TW-6.2 and a BBT-69.2. Alternatively you can use a Park Tool BBT-9 (see at the bottom of this external notch section).
Attach the bottom bracket tool to the torque wrench and remove the lock ring.
Replacement is easy enough, but it should be replaced with the correct torque, in this case 40Nm, so you should include the torque wrench in your travel tool kit.
Alternatively you can use this Park Tool BBT-9 for removal and replacement but make sure you apply the appropriate torque when securing the rotor.
Center Lock with Internal Spine
This is the same as above but with a cassette locking tool. You can use a Park Tool FR-5.2 with the TW-6.2 torque wrench.
Alternatively you can use an integrated tool as in the photo below. This is the same tool as used for the removal and replacement of the cassette. As before if you do not use a torque wrench make sure that when you replace the rotor it is securely tightened.
