I have some of this with longer rides. I think that it's a little like when you sit too long in a cross legged position and your leg gets zingy. It means you need to move your hands. I reposition, take my hand off the grip and flex and extend it, take a break. I think putting a little flex in your elbows help. Do experienced riders _never_ experience numbness? Gloves help but not sure it can be entirely eliminated. What do others find?