The sound of a tire lightly rubbing something once every revolution may be caused by loss of tire pressure due to a slow leak in the tube, especially if all moving parts were quiet for the first few miles of the ride. You might stop to look for the area that is being rubbed, but find nothing because the shape of the tire is different without your weight on the bike.

I like to set my odometer by measuring the distance the bike travels in one revolution of the wheel while my weight is on the bike. I have noticed I ought take a new measurement after changing tires. Sometimes the diameter of the new tires is just a bit different, even though they are the same size.

Back in the early 1970s Schwinn sold a tube of white grease for bicycle bearings. Auto parts stores sell a lubriplate grease for use during engine assembly. It is a light grease very much like the grease Schwinn sold.