Those are not "bash guards" they are chain guards that acted as pants protectors. Schwinn started putting them on 5 and 10-speed "lightweights" in 1967 so that your pant cuffs wouldn't be caught between the chain and outer chainring even if you didn't use pants clips. The one year only '68 S/S Tourer had a triple front TA crankset that didn't use a chain guard, however when Schwinn re-introduced that bike in '71 as the Sports Tourer they had both of the crankset suppliers (TA and Nervar) include chain guards (i.e. pants protectors). They were eventually removed in '76 when the Sports Tourer was re-introduced as the Superior.