Looking at tubes they all appear to be sized in inches so what would the proper size be for the street bob front and rear wheels?

19 x ?

17 x ?

 

front= 100/90/19---100mm is width. 25.4mm/inch--so 100/25.4=3.93 inches wide so I think you'd be good with 19X 3.5" to 4"

rear 160mm=6.29inch so 17 X 6 to 6.5" should work

if its a 180---180/25.4=around 7"