So I've been googling and trying to understand different type of bottom brackets and every just escapes me. Can somebody put it into simpler terms for me? My bike has a cartridge type bottom bracket but all the groupsets I see for sale online come with a variety of different ones that don't seem similar at all. Can anybody help?

YOu can read through these and get a feeling about the different types and what to do if you want to swap. The cartridge type are not as popular any more and have been replaced with external bearings and BB30.

https://www.parktool.com/blog/repair-...ottom-brackets

Your BB needs to match your crankset and your frame's bottom bracket threading. If you are just looking to replace your existing BB you need to buy the same type (square taper or isis or octalink), spindle length (something between 100-130mm) and threading (68mm English is a tyical designation).

If you are changing cranksets you will have to buy what ever is specified for your new crank (that also matches your frame threading). Modern cranks tend to work with bearing cups that thread on to each side of your frame and the the 'spindle' is actually part of the drive side crank that extends through and then the left crank arm attaches to it.

Rotor realizes how confusing this is and has put together this chart. I hope it's what you are looking for.

The chart is easy to follow, but I don't see where the BB 90 on my Madone fits in the scheme of things.

Thanks for all the charts and links everyone. I think I'm getting close on this. Long story short I'd like to upgrade the group on my bike from my tiagra/fsa mixed triple to a full 105 double group. I'm not using the small ring up front and would really just like to make a moderate upgrade to my bike. I'm looking at some 5600 sets since I prefer the black anyways and don't need the most modern set just for a color upgrade. However, I would like the internal cable routing and I think means I need to get 5700 instead. Is that right? The best I can tell so far is that I have a 68MM wide bottom bracket and my frame is not threaded. It's a 1.5 if that matters at all. Thanks in advance everyone!