Ok, really noob question here, but will any bottom bracket fit into any frame? Or will only certain bottom brackets fit into certain frames?

no

That is what I feared. Bleh, back to researching then.

what is the question?

the most common bottom bracket is a 68mm english thread though. so just stick with that

There are different thread patterns, and then there are types that fit the bearings into the frame directly.
but Japan and British commonwealth and former colonies use British pattern .

NB right/drive side of the frame is Left Hand Threaded the other is RH thread.

The bottom bracket is the interface between the bike frame and the crankset. As such is has to match both.

Frame issues include the BB shell width, diameter, thread pitch and direction. For practical purposes, diameter, thread pitch and direction can be summed up by saying English, Italian or French. Don't assume that a bike frame with an Italian sounding name will necessarily take an Italian bottom bracket.

Crankset issues are spindle length and square taper, splined or exo-bearing interface. All of these issues ar typically specified by the crank manufacturer. Sometimes the specified spindle length will be an option (113/118). If that's the case choose the 113 spindle length if your rear dropouts measure 130 mm, and the longer, 118 version for 135 mm dropouts.

Oh - and if you think your question was stupid you should see what has happened to some of the people who didn't think to ask it.

My question to you is what kind of frame and crankset do you have (or think of getting)? I think it would be a lot easier if you told everybody what frame and crankset you have and we can easily tell you what bottom bracket you will need.

Before asking a "Really stupid question" (of which there are none in reality) check out Sheldon Brown's site. So much to learn there. He did us all a great service by publishing his knowledge in a straight forward understandable way. Here he has much on BB sizes. But don't stop there read everything he's got and refer back often.

+ a billion!

Yes, I have read Sheldon Brown's site, hundreds of times. Sometimes though I need to hear it straight from other people, I'm slow like that. I starting a fixed gear project assembling pieces from the ground up, and am slightly unsure about BB sizes. But tons of good info here, and that is why I ask here

what frame?

what crankset?

Ok lets say the SRAM Omnium: https://bikeisland.com/cgi-bin/BKTK_S...ls&ProdID=1371
paired with a Pake frame (I know, sue me): https://www.universalcycles.com/shopp...&category=2593

It says they both accept 68mm. Now, on the link to the crank with the included BB, it asks me to suggest a length, one being 165mm. Is this the length of the crank arms, or the bolt diameter? I'm looking for some decent frame suggestions, not looking to spend more than 800$ though. \

$800 can get you a very nice frame, Lugged Leader, Wabi, Soma Rush, Toyo Godzilla, BareKnuckle, vintage frames on eBay..etc etc.

Omnium will be compatible with the Pake, Pake IMO are perfect beater builds, slightly on the heavy side but they are perfectly fine. 165mm indicates crank arms length and 144mm is Omnium's BCD.

The Pake frame has a 68mm English Thread BB Chamber

The SRAM Omnium uses a 68mm English Thread Bottom Bracket

so it will fit.

Excellent, exactly what I was looking for. I figure if I skimp on the frame a little, I can splurge more on other components. Or is the frame the best area to spend most of the cash?

a frame that fits well and has the desired geometry is probably priority one.

the only thing i would really splurge on is a saddle.

it doesn't really make much sense to spend a ton on certain components and cheap out on others.

Is the Pake frame really any different from most other entry level frames (Kilo TT, Windsor Hour, IRO)?