The treasure trove of Royal Enfield pictures at Sheldon's EMU includes some curious machines.
First, an "autowheel",
Then a 1916 triple, years before Triumph!
Apparently this two-stroke triple was a first in the world, according to
Mick Walker's Royal Enfield, The Complete Story. It was even a 675cc, just like the current Triumph Street Triple!
And finally a 1919 four, years before Honda!