Hello...I am new to this forum. I am trying to help a friend restore her old bicycle she rode in the '30s and '40s. She is looking for a rear fender for her Rollfast bicycle. I am not sure what size this bike is. The OD of the rear tire rim is 20 1/2". Would this be a 21", 24", or something else. Is the height of the tire above the rim included in determing bike size?

The old rear fender has a maximum height of about 12" from a perpendicular line projected between the ends of the fender. The horizontal distance between the ends of the fenders is 27". The shield on the front says "Rollfast, D.P. Harris Mfg. Co., New York, Made in U.S.A.

Any help in determining the size of this bicycle and/or finding a rear fender would be appreciated.