Believe double back and double pike are both c dismounts. Pikes are generally learned after on every event because they’re considered harder- but it doesn’t necessarily have to be this way. I prefer pikes on every event, floor and vault went straight to pike shape. I find it easier to rotate this way when grabbing my legs and bring them in tighter, although if a tuck position is done properly it is easier to rotate. If you feel more comfortable in the pile try out both and see what works, point is unless you decide you wanna do a full in dismount on bars (need to really rotate in a tuck for that) then a double pike is great too!
