Originally Posted by danm
Just based off of some quick measurements and calculations on my 156, it LOOKS like the 165x will be around 28 cm at the inserts. This of course presumes that the waist and insert width proportions are similar. I could be way off though so best bet is the physical foot method. You could also try to find a shop that has one in stock and ask them to measure at the inserts.
That doesn't seem too far off because my Heritage 166 is 26.9 at the waist and I have 30.8 cm feet (size 15 boot, but I think my boots run a bit small cause I am a 14 but these are still tight after 2 seasons) and I get about an inch and a quarter overhang on each side. For what it's worth anyways...