disc pad material separating from backing plate?

[scotsbikester]

I've got Avid BB7s. The pads are SRAM's own. Today heard all sorts of squealing and scraping, from the front. Made it home OK using just rear brake. Got them out just now. Just on one edge of the pads, a small amount of the friction material has detached from the backing plate. And I think another section is about to (see crack). There's plenty of friction material left. I've replaced them anyway.

Photos attached. The two edges where this is happening are the "trailing" edge of the pads, in other words the edge where the disc leaves the calliper (rather than where it enters the calliper).

Any idea why this might happen?

Thanks.

 

[Drago]

It's happened due to faulty manufacture. I had a Hope pad do this many moons ago.

 

[scotsbikester]

Thanks. They've done 882 miles (I use QuantifyMyBike)