>>1088569>Give me a quick rundown on what styles of bottom brackets are good and which ones should be overlooked>pulled an old ultegra bb out of a used frame i bought and don't know how to tell if it's worth replacing or if i should keep it>also if i replace it, what should i replace it with, even?There are advantages and disadvantages for all of them.
Square taper gives you control over the Q-factor of your cranks. You can buy them in different widths to get specific chain-lines. But this is also annoying if you have to buy 4 to get it just right. Shitmano cartridge BBs are awesome and cheap. There are "loose ball" bottom brackets that are extremely simple and keep, but you gotta pull off the cranks and re-grease them regularly. Mostly for retro-grouches, extremely frugal nerds, and 3rd world bike touring
Modern cranks do it differently, they have sealed bearings like teh shitmano cartridges, but come in two pieces that you screw on to each side of the da BB holez. There are fucking 100 different flavors and half of them suck dick. Go for GXP or BB30. Do not mix different crank brands without googling it. I don't know if any different combos work.
Inside teh above modern category is the "press fit" shit which doesn't use threaded bottom brackets and ppl seem to hate so I have never tried.
The worst situation you'll experience with a shit bottom bracket is clicking and creaking sounds from sand or bad installations. I would not spend big money on ANY type of the thready ones unless you a racer
That's all I know. I might be wrong about some stuff. I have only used the GXP and the two square-taper types I mentioned.
I rec shimano un55 over un54 because 54 comes with a plastic cup on one side which is fine but also lame
