For the last few years I was using the Simms Hardbite Cleat, a good stud that has a roughed up surface to adhere to polished granite and other types of rock. The rough surface is key to any stud as they provide a better grip both in and out of the water. The problem with the simms cleat was the threads on the screw that held them in place. With a small flange to them they pulled out on me continuously, even when glued on. I worked for Solid MFG back in the early to mid 90's, a high end snowboard company, so I know all about adhesion properties and laminating. With proper prep and the highest quality glue sold over the counter, the Hardbite Cleat still pulled out. It got to the point where I was spending a ridiculous amount of money, even at cost. It was more about spending time on the boots when I had other things to do to prepare for my guide trips.
Enter Redington, and by partnering up with Goat Head Sole Spikes from the Wasatch mountains of Utah, they were able to bring it into the mainstream of the fly fishing industry. The four-way split head design mimics the hoof shape of one of nature's great rock hopping artists, the South African klipspringer, which name means literally "rock jumper". Their hooves have a four-way split nail that provides 10-times more traction than common animal hooves. I've been using the Goat Heads for the past two weeks with over 40 hours of testing time, enough to be able to give you an accurate review.
First off, the larger flange on the screw holds into the sole much more efficiently than any other screw in stud. I matched the Goat Heads to the bottom of my Redington Prowler boots, and after 40 hours of scrambling along the mine field of boulders on the North Fork Yuba River none have pulled out. The only thing I have noticed is that they do wear down and do not bite like new. Keep in mind I'm on the river way more than your average fly angler, nearly everyday. Is a different type of metal needed for longevity? Now that is the question.
The kit itself is user friendly coming with its own driver tool (1/4" socket), and the application is easy, just requires a little bit of effort to get the screw started. I feel Goat Head Sole Spikes are worth looking into if you want better traction while roaming the Sierra. You can order yours by going to Redington's website HERE