22.2 is for 1" roadie, MTB and cheaply-made forks that use thinner wall tubing. BMX forks, many cruisers and aalmost ALL older U.S.-made bikes use 21.1. Chances are good that a taiwanese-built springer would be 22.2, but that's not 100%. Why don't you take the springer over to an old BMX stem, and see if it fits tight?