Originally Posted by Jamt
Also, I believe that the actual lateral movement of the CoM is very small when you counter balance. The lower body moves one way and the upper the other.
Exactly. To be in balance the actual CoM should move laterally into the turn just enough to match the resultant force vector. Due to the fact that Gravity is also contributing to that vector, in addition to centripetal forces which are actually rather small in the early parts of a turn; the resultant force vector is actually not very conducive to having the CoM inclinated at first. Generally we will be desiring more edge angles then that. The only way to keep the CoM in balance on that resultant force vector while also developing more aggressive edge angles is to counter balance early. Counter balance is even more important in high-c because when you're upside down Gravity is pulling at an angle relative to slope and centripetal force such that desirable inclination of the CoM will be in less. The steeper it is the more this will be the case that the upper body will need to counter balance so that the lower body can be inclinated a lot to create edge angles without inclinating the CoM out of balance.
Is it necessary for the upper body to actually move uphill? It might be, or it might not. It might particularly feel like it in some cases. Get over it drill can "feel" like that sometimes particularly with a long slow crossover or reach across situation. But personally I think that way of talking about it is an exaggeration made by someone who doesn't generally believe in early counter balancing development. I think most times neither the CoM, nor the upper body, nor the hips actually move uphill. But to counter balance you definitely have to make movements away from downhill. Moving away from downhill while you are moving downhill does not mean you will actually move uphill. But you are slowing down the downhill progrrss a bit, basically restraining the CoM from falling out of balance down the hill.
If you want to be in balance, counter balance at the top of the turn is incredibly important. It will not neccessarily be huge amounts of angulation initially. Depends on many factors but the slower you go, the smaller the centripetal force, the steeper the run, the more you need.
This is a tangent a bit from the thread topic but I will just say that when your focus is on flexing and relaxing your joints to move inside, it's way easier to counter balance then if you are pushing and extending on the outside leg to move inside.