J-RAD 1921 3607-115

J-RAD 1921 frame # 1485

This unique bicycle was designed by Paul Jaray, an Austrian pioneer in aviation and streamlining. He is well known for his significant contributions to the development of the Zeppelin and for his streamlined automobile designs in the 1920s. It’s said that the design principles behind the J-rad were based on the shortcomings of conventional bicycles—issues Jaray observed while teaching his children to ride. For instance, the seat height allows the rider to start and stop with both feet touching the ground. Furthermore, the lever-and-cable drive system requires constant effort and eliminates the “dead spot” associated with the highest and lowest points of a conventional pedal stroke. Consequently, mounting and riding off on the J-rad became—quite literally—child’s play. The design originated around 1919, and following the creation of several prototypes, production was undertaken in late 1920 by Hesperus-Werke GmbH in Stuttgart, Germany.
In addition to the standard model featuring three pedal positions on the drive levers, a version with two pedal positions was manufactured for the Dutch market. And while the J-rads intended for Germany were equipped with beaded-edge tires, the model produced for The Netherlands was fitted with wired-on tires.
The bicycle features F&S Torpedo drive units on both the left and right sides of the rear wheel, each connected to a large drum. Cables are wound around these drums; the pedal levers pull and unwind them. A third cable connects the two drums, ensuring that as one drum unwinds (driving the wheel), the other is rewound. Production ceased around 1923. The Torpedo rear hub is fitted with two gears; there is a lever under the left side of the saddle to switch gears.
A total of approximately 4,000 units were built between 1920 and 1923. Currently, just under 100 surviving J-rads are known to exist. A few Dutch versions featuring two pedal positions have also been preserved. For a full description of the J-Rad in general, we refer to the very informative and comprehensive website: https://j-rad.ch/
The machine on offer is a Dutch version that is is in nice authentic condition. She comes with period acetylene front lamp and 26 x 1 ½ tyres.