Will this possibly work? I'm trying to piece my wife's bike together and have a few parts laying around.

yes, not the best but yes

Thanks, I'm running brakes with a freewheel cog right now and will probably go with a 1/8 cog on the fix side when I get around to it.

I don't think my wife will ever want to ride her bike fixedgear anyway

Yes, it's fine. Some catalogs even sell the 3/32 cog as "suitable for 3/32" and 1/8" chain"

It will work with a 1/8" chain.

OP asked the wrong question. And you might want to qualify that with a "will ONLY work".

I'm running a 3/32" cog with 1/8" chainring and chain, and I've got no problems whatsoever.

thanks everyone, I just got done putting it together and it seems ok.

You'll need to use 1/8" chain of course, but that will work fine with your 3/32" cog.

That's one reason I like to run 1/8" chain -- it works with either 1/8" or 3/32" drive train components, so you can mix and match to your heart's desire.

Didn't know where else to ask this so I apologize for going off topic, but does anyone ride a 48/14 gear setup? I normally ride 48/16, and do ok on hills. I'm planning on doing a short triathlon on my fixed gear and wanted to have a better gear ratio. I'm thinking any decent hill will kill me, but I don't know.

48/14 for anything besides relatively flat is idiotic.