After installing the SPD cleats and testing them on my spin bike, the plastic completely detached from the bottom of the shoe. It may have been an isolated incident, but I'll look for shoes with a more durable shell. Very disappointing as the boots look and feel good. Was excited to test them out on a full ride but doesn't look like it. As a side note, these appear to be refurbished shoes. There were a few black spots on the outsole and the Delta cleat inserts were already in the shoe and looked like they had some kind of glue on them.