So I met up this morning with Chris White, a fellow Cat 3 racer, a former Black Diamond employee, and engineer. The subject? How to make F1s lighter. And he was kind enough to share his secrets with me and to let me share his speed secrets with you. As you can see, Chris has gone to great lengths to minimize the weight.
There are several things note in this picture (click to enlarge):
1. The cables have been totally removed.
2. The heel throw has been modified (more on this later)
3. A bungee cord has been attached to the heel throw, which acts as a "spring" and holds the throw up while skinning.
4. The ratchet buckle has been fastened onto the cuff.
5. There are lots of holes in the cuff.
Note that lever on the heel throw has been removed and some of the aluminum has been milled out (the newer F1s do not have a lever).
Chris also shaved off some plastic on (a) the bottom of the cuff in order to get a longer stride, and (b) on the heel throw notch in order to be able to flip the heel throw open with his hand.
Chris drilled some holes in the heel piece under the liner. I'm sure that reduces weight by a few thousandths of a gram.
Chris got this cordura tongue from a Scarpa rep. It provides protection from snow, a bit of padding, and a bit of support. I dig the Scarpa logo.
All extraneous plastic on the ratchet straps has been hacked off. Chris keeps the top cuff closed with the ratchet strap even while skinning, and then locks the heel throw down for support on the descent. There are holes drilled in the buckle strap.
"Extraneous" rubber is ground off from the arch of the boot. Good to leave a little bit there to prevent slippage during booting.
The heelpiece for this Dynafit binding was made from scratch in a machine shop. My understanding that M. Santurbane had a lot to do with this -- that was before he was a pro cyclist.
The skin attachment on the tip is a BD skin fastener that usually fastens on the rear. I think I'd opt for a notch in the tip, but Chris' solution is very creative.
Skins are cut short and tapered at the end.