Well, I have had my 2000 Cannondale F300 for a couple of years ago, and up until two months ago it was working perfectly. It is really falling apart, I live in New England and there is tons of hilly terrain so you can imagine the general abuse on it would break it eventually. I knew from the day I got it it had junky compenents (SRAM 5.0 rear derailleur, low-end Shimano front derailleur). My rear rim because so badly bent that the spokes started snapping. So while I was replacing the rim, i was going to replace the the rear derailleur and convert bike to a 9 speed cassette and shifters. When i was removing chain, i noticed the crank was badly bent. I have a low end Shimano crank on there now, and i'm going to replace it with a Shimano LX. Will I need to replace the bottom bracket to put on this new crank? If so, does anyone know which size i need, 68mm or 73mm? Thanks in advance.