The old Royal Enfield is a 1914. The sign in front of it said it was sold in New Zealand on the first day of World War I.
You probably already know this but for those who don't:
The engine seems to be the 225cc two stroke, the first year a two stroke was offered by Royal Enfield.
It was first introduced in 1914 and coupled to a 2 speed transmission.
ROYAL ENFIELD, The Complete Story, (writing about the 225L model) says,
"...The three-port, two-stroke engine with deflector piston, outside flywheel and two-speed gearbox gave modest performance..."
Noting the rear chain drive with what appears to be a drum inside the rear sprocket it appears this motorcycle had the famous Royal Enfield "Cush drive" system that was first used in 1912.
Many motorcycles during this period used leather belt drives because they dampened out the shocks that could be transmitted thru a real chain drive. The Royal Enfield design used a rubber shock absorbing device to eliminate these hard shocks and it is still being used today on all of the RE motorcycles.
The large ring on the right side of the rear wheel is similar to a giant V groove pulley. A V shaped rubber wedge was pushed into it on the forward side to serve as the only brake.
The headlight is an acetylene gas light. The acetylene is produced by slowly allowing drops of water to fall on the dry Calcium Carbide in the body of the light. It was a common, but not very effective form of lighting for a lot of motor vehicles at the time.
The horn is a Antique Klaxon Plunger Horn which produces a "OOOOGGAAH" when depressed.
Neat stuff.