I'm back from Mt. Shasta. Short answer is that I didn't summit and I learned much more than I planned on.
For reasons that it took me a day or two after the summit climb to figure out, I was moving slowly - even with a light pack. As we climbed, the fatigue in my legs increased and something clearly wasn't working and it was obviously not a summit pace, so at first offered opportunity, I opted to go back down (I got up to around 10,400' or 10,500'. Now I've been training for this for months, so it wasn't like I was out of shape. I had gone up 2 days early so I was acclimated and was not sick at all. I was convinced I had no excuse and no reason which is a little maddening.
After a day's reflection, it finally occurred to me that likely I had some residual leg weakness that only showed up under the very demanding conditions of Mt. Shasta (elevation, snow, climbing a steep slope in crampons), and didn't show up at sea level workouts or even ordinary hiking. It's 3 days later and my legs are still tired and have a bone deep fatigue.
Unfortunately, training for such a moving unknown target is really difficult and sanity suggests that perhaps I want to look for another obsession that's more suited to where I live. I love where I live and have absolutely no plans on moving to the mountains. I like visiting the mountains, I love the challenge of climbing, but I don't have any compulsion to live there and even spending the extra time to acclimate I kinda resent as it takes me away from Terri and the dogs.
So here I am wondering what to do.
I think summit dreams are now on a very lengthy hiatus, while I go pursue relatively easy goals like climbing Mt. Diablo on a bike (already have done it on foot multiple times), or day hiking Half Dome, and toy with getting more seriously into biking again. doing more rock climbing, and try to find a way to recreate this leg weakness issue so it won't interfere with skiing next season - I may have to start lifting more heavy weights or at least bench pressing them. (I'm not a weight lifting fan so it's going to take some attitude adjustment.) Shasta, for now, will be a ski and glissade destination - which is not a bad thing at all.
So I'm disappointed, but feel freed in a way as well.