bottom bracket yes...derailleurs not necessarily. The triple front derailleur will work, just adjust the limit screws. The triple rear derailleur will have a long cage that's there to take up slack when your in the granny ring of the triple crank. Since the double will not have as much slack in the chain, the rear derailleur will act as normal. A shorter cage may allow faster shifts but not really too noticable. Just change the crank and BB. Just use the granny and middle ring settings for the front.