I followed Mike's advice and I'm very satisfied--size 10 shoe on Wabi Classic. A big improvement over single clips.
Itook time to get use, but I really getting now, makes me want to try clippless.lol
I bought these toe clips in black and they were great. These double clips paired with leather toe straps offer such a connected feeling to the pedals and keep your feet very secure. I would not recommend anything less than double clips and straps if you ride a fixed gear, especially if you ride brakeless. The bridge-piece between the two bars of the toe clips offers additional structural integrity which other toe clips do not offer. Being metal, these clips really held up well to daily wear and tear, although the paint did not hold up well, which is the only reason why I only gave these four stars. My shoe size is 10.5 and the medium size (50mm) suited me nicely. Overall they are a great product that I am currently enjoying on my Wabi Special.