I bought some new shoes - the Scarpa Vapour V - which is meant to have a 3.5mm Vibram XS Edge rubber. However, when you measure the thickness at the edge of the shoe it is exactly 5mm. I looked at a few other shoes that are meant to be 3.5mm but they have the same feature - the rubber measures 5mm at the edge.
What's going on here? Do they use thicker rubber at the edge and 3.5mm is just in the middle? Which part exactly is meant to be 3.5mm?
I've usually stayed away from thinner rubber shoes because I'm worried they will wear out too quickly, but it looks like most of them are 5mm at the edges anyway.