Originally Posted by cudak888

Not necessarily - depending on how much Schwinn centered their drilling, you might find that you'll ream right through the locknut washer slot.

Curiously enough though, I have evidence of Schwinn reaming one of their own 21.1 FORKS out to 22.2. Apparently, the AVA bar and stem on my '71 Schwinn Continental weren't Schwinn's standard bag of parts - sure enough, the fork was reamed out to 22.2, and there's a small (offset, no less) ledge in the steer tube to prove it (also proves that they didn't ream it out properly).

I ultimately used a donor fork on that bike, which came in the Schwinn standard 21.1 size.

As for your machine, if you want to use a stem other then stock, just haunt eBay. Many machines into the '80s used 21.1 stems, especially some of the nicer department store machines with their SR Custom stems. Another case - I recently pulled a Gran Compe stem out of a Nishiki. Very nice stem usually on better mid-range machines. Sure enough, 21.1.

-Kurt