The Stoptech rotors are pretty high quality and generally last a long time. There are several factors that can affect their life like how hard they are used, how good your cooling is, what pads you run, etc. Thermal shock is the hardest on them and can cause the cracks to grow.

Those rotors are still fine to use as is. They might last several more years or just a couple of events. The general guideline is to toss them when a crack extends to the edge. When that happens, the internal stresses inside the rotor can cause the rotor face to distort in an offset and create a step. This step will be felt in the pedal and even the steering wheel every time it hits the pad. This can very rapidly shave the pad down or even cause a wheel to lock. Again, the quality of the Stoptech rotors usually means this step will be pretty minor. Cheaper rotors can quickly form a huge step or even have the rotor come apart.

Those look old enough that it would be wise to bring spare rings to the track and have everything you need to swap so you don't ruin an event if a crack grows to the edge. It's always a good idea to inspect between sessions to catch things before they go bad on track.

Also, between events it's good to inspect for wallowing out of the holes between the hat and the rotor. A couple of people have had issues with that and if left unchecked it can take out both the rotor and the hat or even result in complete brake loss at one corner.


Richard P.