I am converting an older Schwinn that has a Sugino crankset where the large chainring is actually part of the crankset (can't remove). I don't have a problem in general with running the fixie on the large chainring, unless I hate it down the road. My main question, though, is will the chainline be ok running from way outside on that large chainring if I push the sinlge cog way out toward the frame in the back with spacers?

Can't really push out a track cog. If you chainline is bad you can do a couple things.... new crank, bolt on inner ring and just run or cut off the outer ring, find a used crank at coop/lbs...

If you mean spacers on the axle, then yes that will work. But you'll have to re-dish your wheel a lot which may cause problems with spokes breaking if it's an old wheel. You're better off running the inside ring (much better chainline) or getting a new crank with removable chainrings.

That is what I was worried about. I bought the bike for 50 bucks and I really am priding myself on doing this cheaply w/o buying parts. One thing i don't quite understand is that if that chain line would have already been one of the options during normal operation with the cassette and double front rings, why do I need to redish? The spacers would go on the inside the original cassette and the wheel will still be in the same place between the dropouts, wouldn't it? In other words, I'd set it up like I was just in 52/18 during normal operation? or is that chainline going to bounce off w/o a derailer? Ah, I think I answered my own question there. W/o the derailer the chain line is wrong.

I guess I'll run on the inside until I can get a new crank. That will work fine. Cutting the outer ring off completely is a good idea, too. Then I can just use a conversion kit and I think I'll be fine.

Yep. Derailer systems can run at a considerable angle. It won't be as efficient as a straight chainline, but it generally doesn't cause a problem unless you're doing dumb stuff on purpose. Without a derailer the chainline needs to be quite straight or it will create noise and grinding and possibly fall off.

You can create the same gear ratios with your small ring, it just might look a little goofy with the big outer ring sitting there.

Ok, thanks. Time to face the facts. There is also a very light chainring guard that might hide that ugly outer ring, but then adding weight. It'll ride, though, and I'll keep my eye open for cranks.

I just read on another forum, that I can flip my old bottom bracket to bring the big chain ring closer to the frame. Sounds like a good option but couldn't find any other info on it.

That might actually work. Two possible issues:

1. The left arm will be sticking out further, which may feel awkward.

2. Before you you flip the spindle, look at how much clearance you have between the large ring and the chainstay. In my experience converting old bikes the big ring will hit the chainstay before you can move it over a decent amount. But if you can move it over a little it will give you better chainline, making re-dishing the wheel more reasonable.

Cool, thanks. I'll lube that sucker up and see how it looks in there backward. Yeah, might be weird with my left foot out that much further than the right. Odd.

Really depends on the hub axle, If you can fit it there and still have a lip and close the lock ring down then yeah, Just becareful about the chain line hitting the frame, On my road bike at the top chain ring and lowest cog my chain rubbed on one of the welds. I had to sand down the weld a little bit to avoid the rubbing.

I just wanted to post an update so any others who are doing the same thing might get the information. I flipped over the bottom bracket and repacked the bearings. I bought a cheap old Regina single speed in town and the inside chainring is lining up pretty dang well with the rear cog now. It's not perfect and I haven't jumped over an curbs, yet, but my first ride was good. The main problem now, though, is that it's running on 42/18 which is way to slow, so I'll just get a new chainring and plop it on there when i get a chance. Thanks for all the advice, I'm super excited to ride it though the new brakes are a little sticky on those old Weinnman rims.

If you get a new chainring, just make you get one with the correct bolt circle diameter: https://www.sheldonbrown.com/gloss_bo-z.html#bcd

Personally I'd just get a 15 or 16 tooth cog, as it will probably be cheaper than a chainring unless you find one used. I'm running my conversion 42/15 and I'm happy with it.

The problem is that I bought a threaded freewheel singlespeed for 15 bucks. Might be just as hard to find either one. Maybe I should look for both.