folding bike logo
The Folding Cyclist
— The Site for Folding Bike Enthusiasts —

1959 DNB Porta-Fold Cycle



This interesting folding bike was submitted by a reader who purchased it from its second owner who kept it in storage for years.  The bike is in pristine condition with the original protective wrapping still on it, quite remarkable for a bike that is over 50 years old.  It features a double fold frame, while not unique, it was unusual in its era.

The bike was made in Japan by Dai Nippon Bicycle (DNB), a Tokyo based manufacturer of bicycles. DNB set up a U.S. distribution company in New York City which serviced a network of dealers.  One of their ads is shown below following the photos of the bike.

The bike was designed by Shoji Tanaka and Yoshiyuki Katori who filed for patent in Japan on Oct. 30, 1957.  A U.S. patent was applied for on Oct. 22, 1958 and granted on Jan. 2, 1962.  Drawings from the patent are at the bottom.

DNB Porta-Fold Cycle 1

DNB Porta-Fold Cycle 2

DNB Porta-Fold Cycle 3

DNB Porta-Fold Cycle 4

DNB Porta-Fold Cycle 5

DNB Porta-Fold Cycle 7

DNB Porta-Fold Cycle 8

DNB Porta-Fold Cycle 9

DNB Porta-Fold Cycle 10

DNB Porta-Fold Cycle 11

DNB Porta-Fold Cycle 12

DNB Porta-Fold Cycle 13

DNB Porta-Fold Cycle 14

DNB Porta-Fold Cycle 15

DNB Porta-Fold Cycle magazine ad 1958 

DNB Porta-Fold Cycle patent drawing