WWI items from one lot - Overseas RPC Photos

Still more from the eBay lot I just acquired.

Photos 1 and 2 are real photo postcards of two different people, but the same motorcycle, same background, with kickstand obviously down and wheel up. I imagine one took a photo of the other then switched places. Anyone know what type of bike it is? The fellow in photo 1 looks as though he’s wearing fisherman’s rubber waders! They extend to mid-thigh, and frankly, if he was cycling all over WWI France, the idea isn’t quite as crazy as it appears. I don’t know of any other footwear it might be. I can’t figure out what’s wrapped around the nearest handle bar. The other handle bar seems to have some sort of horn.

Photo 3 - The cyclist here is the same fellow as in photo 2. He wears an issue winter cap, and although he had gaiters in the second photo, here he has wrap around leggings, and has now acquired an overseas stripe. His sidecar reads “MEDICAL DEPARTMENT” and “US ARMY.”

Photo 4 of the three soldiers, the one on the left appears to have pulled his shirt collar up over his stand up jacket collar. He and the one in the middle seemed to have gained some weight since the uniforms were issued! The one on the right may have crossed rifles (infantry) crossed swords (cavalry) or crossed cannon (artillery) on his collar disk. All of these RPCs are marked “CARTE POSTALE” on back.