Hi Elliott - I'm not sure what a 26.5 boot sole length is, but as I own F1's, F3's and Dynafit bindings, I suspect I know the answer to your underlying question of "Will these boots fit my TLT bindings, which were drilled for F1 boots?" The answer is "Kind of." The real problem/issue is that starting with the F3 (I think), Scarpa moved their Dynafit front pin holes back 2mm (4mm?) which makes them tour much than the old pin hole locations in the F1's as you don't have to lift your foot as high with each step and it is a more natural stride. This caused a situation where you can have a pair of F1's and a pair of F3's of the same size, and even of the same sole length, but they may not fit in a TLT binding as that binding only has 4mm of adjustment. If the binding was mounted properly, as in right in the center of the range, when you go to switch boots, there is barely enough adjustment to cover one of the boots. There are two solutions to this. One is to buy/use the TLT Verticals, or one of the newer Dynafit bindings which have much more adjustment. The second option is, if you know you are going to be using two pairs of boots (F1 & F3) with the classic TLT binding, split the difference between the HEEL TO PIN HOLE length and drill them there. I suspect that Scarpa will soon have all of their boots on the same program, but for right now, the F1's are older molds than the F3's. I can get my F3's to work in TLT's mounted for F1's, but there is barely any heel pin engagement, so I'm careful about what I ski with them.