Of all the helmets on this list, the Closca Loop looks the most futuristic, like something out of Spike Jonze’s set-in-the-not-too-distant-future dystopian romantasy Her. With a bit of pressure on the top of the Loop, the helmet collapses down into itself (think one of those old-school camping mugs that collapsed down to the size of a hockey puck), becoming barely larger than a laptop. My only knock on the Closca Loop is that there is no fit system (that is, no dial on the back to loosen or tighten the helmet around your skull), making its fit a bit less precise than dial-fit helmets.