1920s Columbia Motorbike

Well, at this point I am not absolutely sure what this bike is. But the badge on my Columbia Racer fits this bike perfectly. And the marks on the original paint showed it was a round badge just like the Columbia badge. So, I am fairly sure it is a Columbia. The crank seems to be a generic crank. It is featured in old brochures as an option. The fenders are also identical to the ones on the Columbia Racer, as are the shape of the rear stays whre they meet the seatpost tube.