I want to modify a 1980' Bianchi to make it a 2 spees fixie. I have ride fixie for over 3 years but I wanned to do something different and modify this one. I will change the front derraliur between the two gears and keep the derraliur in the back to keep tension on the chain. I preffer fix a lot more, however for the landscape in which I ride two gears would help a lot. Also all te accesories of the bike are campagnolo( caliper breaks, crank, seatpost, wheels) and except for the derraliur in the back which is chimano that way I would keep all of them on the bike. What suggestions do you have?