I recently put a Veloce triple on an Italian frame with a 30.8mm seat tube( I think ). I had to use a 113mm asymetrical bb. The original 104mm bb gave me what I thought was a good chain line but there was not enough clearance for the fd to make the shift to the small ring. I don't know if the Veloce and the Mirage are the same though. I think you will like the triple.