so it has come to my attention that I probably need a new bottom bracket as well as a new chainring and cranks. I have a 2008 SE Lager which I have converted to fixed. I guess I've been kinda rough on it because now my chainring has begun to go out of round and my bottom bracket has started to give a little bit (mere millimeters, but still). The lager comes with 4point cranks so I feel like if I'm gonna put the same sorta stress on my bike, I should switch to 5 points. does anyone have any recommendations as to what I should put down there if I'm gonna be replacing the bracket, chainring, and cranks? Should I bother spending the money to put 'fixed gear specific' parts on?
Go to a 5 arm setup and keep up on the chainring bolt tensions, if done so , next time you will have to change chainrings will be when you wear the teeth out. While it would be ideal to use fixed specific parts with it, you can get away with using non fixed gear specific parts. On my fixed gear, I'm using the double ultegra cranks and just running one chainring on the inside part of the spider for a closer chainline.
For most needs, you can go with a square taper bottom bracket, especially if you are a larger person since a square tapered bb will have larger bearings which equate to a better weight bearing load capability than the smaller bearings found in a splined bottom bracket.