Crank Brothers came out with 2 seats with replaceable rails. Why replaceable rails? I've only seen or heard of rails breaking on very light saddles when they are made thin, they get used alot, they start getting old, and maybe the person riding on it is heavy. Other than this, rails don't break. I find the seat, cushioning or cover, wears out before the rails break. Does having a seat with replaceable rails make sense? They do offer a 5 year warranty on the seat, I wonder if it covers wearing out of the foam or rips and tears?