By Bob Kelley
I checked my references and confirmed a couple of hunches. The hardest years to distinguish are 1928 and 1929, and aside from the primitive wheel rims on 1928 (which people who actually ride the bike would probably abandon), another difference is that 1928 had a compression release rod that goes straight up and down through the gas tank, while 1929 has the whole mechanism down near the oil pump. Again, though, many restorations (like my very rough example) would not have the original compression release (you don't need it; mine has none).
The headlight changed for 1930 from a sort of bullet shape to a much more shallow shape sort of like a saucer.
Also, I think the cross-brace on the handlebars was only for 1931, and this year also had an Indian-face horn under the headlight (it had been a Klaxon horn near the magneto before).
But the easiest ways to tell them apart are: Hinged rear fender,
1930 or 1931; brake on right, 1931. Then to tell 1928 from 1929, check rim
design and compression release. A 1928 that was not restored correctly in
these two respects will be impossible for most of us to tell from a 1929
except my checking the serial number on the engine.
