I have a triple front and rear derailuers on a double crank right now, the only thing is that you have worry about is to set the high/low limit screws just right otherwise your chain will DEF derail. The limit screws on my front derailuer are barely long enough to set the swing just right. I am using Dura Ace STI, with DA front and rear deraileurs.....all triple. But there shouldnt be a problem unless i am overlooking something. Also, the bottom bracket spindle might be a little longer.....someone else with have to give you the details on that situation.