Originally Posted by
recursive
"Ok, I'm in my 14 or whatever, need to make a smooth shift over to the 12 for this sprint or downhill or something... on the opposite end of the cassette... almost got it... wait, where did everyone go?"
Was it actually possible to get any advantage out of such a configuration?
You only use it for the sprint. Usually it's an 11t, and usually only the really strong juniors would do it. It's not that hard to throw the chain from one side of the cassette to the other. You just need to be prepared.