Looking for an explanation about what might have happened to these pads to prevent future occurrences. The failure occurred during the first weekend of use. I noticed a knock-back problem while driving, requiring left foot braking just prior to the braking zone, otherwise I had a very long and soft pedal.

 

The brake pad equivalent of “attach a log and tune” is: “tells us what brand/compound”

 

Only 2 things ruin brake pads. Physical damage from impact and heat.

 

LOL!
PFC 11, installed, bedded in, and then run for 5 sessions. The pad material is still adhered to the backing plate, but one part of the left outboard pad sheared off in a pattern that I've never seen before. These are installed in a StopTech STR-42 trophy caliper.

 

Most likely stored improperly (you or whoever you bought from), or dropped during shipping.

 

That it split essentially off the molded or post machined relief cut smells of physical shock like dropping during shipping/install. Ive never seen the material itself sheer in half, and ive only seen 1 or 2 examples of the material releasing from the backing plate.

 

Thanks for your diagnoses. The pad material is still adhered to the backing plate with the shear occurring several millimeters above the interface. I talked with another brake pad manufacturer who also suggested physical shock as the root cause. As tough as brake pad material is to heat, it can break pretty easily from impact.