How do I "move up" from a hand/fist stack?

So I'm trying to get mileage on cracks/technique in the gym before failing some more outdoors (CCC in BoCan is the goal, I don't live near it).  The one (of two) in my gym (Walltopia if that matters to you) has one that goes vertical for about 10', the diagonal right (about 15-20 degrees off vertical from the starting line) for about 15', then goes back to vertical for another 10-12'.  It starts at a nice hand size, the diagonal section is a horrible size for me (just a bit too large for a teacupped fist but hand/fist works perfect).  The whole thing is slightly overhanging (TR rope hangs about 4' away from the base of the wall).  The top section gets a tad narrower, fist size.  There's feet everywhere (it's a gym) and I'm trying to figure out my hands anyway.  I sent it once 3 years ago not really trying and recall a horrible sweaty sufferfest that had no semblance of style.

My problem is in the off fist section.  The way the route angles/hangs, I can get a decent left arm bar (left palm on the right/lower edge; forearm/elbow counter pressure on the left/upper edge).  From there I can stack a fist and move my feet up.  But here starts the struggle; as soon as I release any pressure on my hands my "up moved feet" have shifted my center of gravity and I fall.  My thought is that my armbar isn't adequate, it should be able to hold me in my new position as I move my R arm up.  If I could quickly set a new jam with my right fist I could probably shuffle my armbar up, but the angle is such that the only possible "jam" for my R is some weird thumb/wrist torquing that hangs halfway out of the crack.

I then gave up trying to "swim" up the thing and my technique has become a gross combination of proper jams with bloody smearing and desperate clinging which feels like balancing on slab more than climbing crack.  There's a technique deficit here right?

can you jam your knee? Knees are hands free jams most of the time. If not it gets more strenuous.

Stack turns into a layback. Shuffle up your bottom hand. Back to a stack to move your feet up.

Ie, fist/hand stack: lean into your hand. Remove your fist and gaston the same side of the crack your other hand is on. Slide the Morton hand up, and return to the stack.

This is much easier in a dihedral, but works fine in a splitter. It is quite strenuous, so don’t expect it to be easy (much different than a hand jam which is dead easy after you learn the technique)

So, if this wasn't a shallow gym crack, the goal would be to shove your inside leg into the crack get some sort of a lock (thigh lock, calf lock, leg bar, etc) in order to go hands free with your core and shuffle your hands up. This width is probably a calf lock, so you'd stick your leg straight in + high and twist/flex your calf to hold yourself in it. If you can get a thigh lock and leavittate, even better. Then, once you reset your stack, you pull with your hands + push with your outside leg to remove weight off the lockk, bring the inside leg up, and lock it. Find videos of tradprincess and other OW aficionados for reference.

Note: you want to rely on the expansion of your thigh muscles for the leg locks, jamming your knee into a constriction is a great way to get it stuck

Thanks for the replies!  Your advice actually brings up a point I forgot; I had tried to use my leg more (calf; knee/thigh doesn't fit) in the early attempts but I often got "stuck."  Meaning I can narrow and twist and get my inside leg in, then move and shuffle everything else up.  But in doing this the left leg gets tighter and pulled in a direction that only makes it more snug.  The only way I've been able to get it out is to move my body back down and "reversing the moves" that I used to get by leg in there.  I gave up out of fear of dislocating something while falling but I should try again.

Does keeping the inside leg in the crack help with the direction of forces?  Similar to vertical cracks and wanting to keep elbows/knees vertical, once the crack goes diagonal do I want to try to keep my inner leg/torso/arms in line with the crack (and the "outer leg" smearing the face)?

Hard to say without seeing it. My one response is to try smaller movements - ie move your feet up like a ratchet. For some OWs it might be 2 inches per "step" for a while. This may help with the balance challenge. (or not!)

Do you think this video might help?

Trophy Crack - Beta spray
A valid method if you have the flexibility.

Getting a calf or knee jam could work too, depending on the situation.

I definitely prefer the leg (calf, thigh, whatever) lock over the lieback. The latter takes too much energy...not to say I never do it. You'll often find yourself mixing techniques, especially as the crack undulates, angles, or has lips.

I don't think CCC has any overhanging wide sections

Yukon Cornelius wrote:

I don't think CCC has any overhanging wide sections

Country club crack? Ya you can do that think without good stacking technique. I know cuz I have shit stacking technique. 

I’m re-reading some sections in Whittakers Crack book and he specifically talks about the inside leg being the “hold you in place” limb and the outside leg being the “move you upwards” leg. This is definitely something I forget when I’m focusing so much on my hands.  

Another issue I’ve realized watching videos is I think I had/have misconceptions about “proper crack climbing.”  It seems obvious my right hand (the lower one/leading one, tends to be the fist on the left wall in a crossed hand/fist stack) needs to just gaston the right edge as I shuffle the arm bar up and reset (especially given the angle at which the climb trends up and right). For whatever reason I felt my hands needed to stay in the crack at all times otherwise it “isn’t really crack technique” which seems to be both false and irrelevant.

Regarding CCC, I’ve never been on it so I have no idea how it goes. I’ve been told it gets “a little wider” than is comfy and so I figure I should climb stuff that’s “a little wider” than I’m comfy on.

Thanks for the input everyone.