So full disclosure I'm not planning on building a fixie I really want to build up a frame with a Sturmey Archer 3 speed... However, you guys are the best at setting/figuring out chainlines etc. So I have a couple of questions to start (been researching and reading for days but I don't know much).

1) Which Frame should I pick?

I Have two to choose from. Either a Schwinn 1988 giant made world sport (I assume this based on Serial of G1118 and head tube stamp of 3338)

OR

Some super weird late 70's/early 80's Sanki (Can't find much on this thing, appears to be some sort of japan import).

They are the same size and about the same condition/weight. I'm leaning towards the Schwinn because I fear the Sanki could have some weird threads etc. Also the sanki appears to have a crimp on rear dropout but the Schwinn is welded on.

2) What do people commonly use for the front chainring/bb? Any easy resource for what I should buy or should I just drop/remove the inside chain ring and try to adjust to fit it to a line that would work with my Sturmey 3 speed? I did some quick measurements and from what I can tell the spacing between my rear dropouts is about 120mm. The center offset (from center of seat tube to outer chainring) is 47mm.

I'm sort of worried that I only about 13mm from the inside arm to the gear. Is that too tight or did I screw up my calculations?

I plan to build the rear wheel so I can dish it as needed (well I'm going to try... lol)

1)The Schwinn will be nice, I have one too!
2) If you already have a crank on there use that, it most likely will work out just fine. If it is visibly off when you assemble the bike then you can think about changes.
3)Are you experienced in truing wheels or ever built a wheel? If not, I suggest you just pay to have to done right and practice on something else. You don't "dish as needed", dishing is centering the rim on the hub. If a properly dished wheel sits off center in the frame then the frame is out of alignment.

Sweet, I was leaning towards the Schwinn anyway so I'll go that route. As for dish as needed I meant I can shift the gear over in the back and center the wheel on it (I have a truing stand and plenty of time...). I've never built up a wheel but it's something I've always wanted to do so here we go! Is it possible to shim the chainring to shift it more inboard?

Thanks for the reply!

The Art of Wheelbuilding Is your best read for getting started.

I have never tried to shim a chainring, so I don't know, but I doubt it will be necessary. If the chainline is really off you either have to change the chainring position or get a different length bottom bracket.

Not sure about the other one, but the World Sport is a tank

They're both about 30lbs. I'm just going to haul them both home and debate some more. The Sanki would certainly be more unique but then again I don't think there's a ton of 79 Schwinn's out there... Anyone have thoughts or considerations to help me lean one way or another?

The crimped dropouts are an immediate indication of a bike shaped object. While the Schwinn is no featherweight racer it will be good quality and ride smoothly.

Do the Schwinn! It won't be heavy when you are done with it.

I have an electroforged 77 Schwinn framed bike. It has the heavy forged fork, 32mm wide rims, steel handlebars, Brooks saddle, Coaster brake hub, and a solid rod of 6061 for a seat post. It's down to ~26 lbs from ~38.

If you build that bike up with modern light "normal" components, unlike what I've done, you should end up WAY lighter than that.

I thought you said it was an 88?

EDIT: I just read up on the 1979 World Sport. It has steel handlebars, steel rims, steel rear hub, kickstand, and both chain rings are steel. You should have no problem getting that thing down to a more reasonable weight.

I found a way to decode the number and realized it was made by Giant in November of 78 as a 79 world sport. Just posted a picture for those who want to see it!

Also, yeah I tested with a magnet and everything is steel lol