Great old shot.. I think it was carbon that was added to rubber around 1921 that turned them black, before that (my guess is the pic is from 1918 or so) they were white.. I belive the bike is an old silent grey fellow HD.. pocket valve 61 cu in.. can't quite make out the logo on the tank.
ah to have my old 1911 back again..they tried to give me one of them new fangled ones with the curved back strap, but i wouldn't have anything to do with it..
When I was a kid, their was a very old bike mechanic that rode one of these to work everyday. He had had it since it was new!
Either a "Scout" Or "Brave" I almost said Indian for sure. But having second thoughts. Not a Harley though.
I cant read the script on the tank...and the V is a 45 degree.. which means excelsior, indian, or Harley.. in the first war they had like 4 or 5 mfgs not like WWII where Harley actually "puilled the plug" on Indian... thier contracts for the WLA actually did lead to the downfall of Indain..anyway back to the scoot... its a pocket valve, which predates the flat heads.. the lever on the right of the tank is the "dog clutch" that controls the belt drive used then (and oddly now) the engine looks to be right out of the silent grey fellow Harley which was a 61 CI or 1 lt.. amazing that they were using Letres then but they were.. the scout and brave were later... you might think this is an indian due to the lever on the right..this is one of the diffrences between H and I ..H has shift on the Left .. I had them on the right...but in this case thas not a gear shift.. anyway the side car rig could be anybodys.. lot of diffrent mfgs for them.. and most people dont realize that before mr Ford introduced mass manufacturing thier were more motor cycles on the road than cars.. Ive read that the introduction of the first mass manufactured Fords led to failure of over a dozen major motor cycle firms.. these were old total loss oil systems... but right for the roads of the day..