Safety low wheel

from Wikipedia, the free encyclopedia
Lower safety wheel Rover III, 1888, original frame shape as rhombus ( incorrectly translated into German with diamond )

The prototype of the modern bicycle was called the safety low wheel (or low safety wheel) at the time of its creation (late 19th century) . It followed the fall-prone because of its large wheels and the wide front seat driver and dangerous penny-farthing . The so-called high safety two-wheeler was an intermediate stage in the development of the Niederrad . With the front fork tilted backwards and the driver's seat shifted well behind the axis of the front wheel, safety was gained by reducing the risk of falling forwards when crossing a ground obstacle (e.g. a threshold). Then you switched to two smaller ( lower ) wheels, which were roughly the same , so that the driver's seat could be moved just behind the middle of the bike. This largely eliminated the risk of falling forward. In general, falls were less dangerous because of the low fall height on this low safety bike.

The pedal drive remained effective thanks to the pedal cranks and the chain drive (on the rear wheel) with high speed translation . There was no need for a large powered wheel, as in the high wheel. The optimal frame geometry in terms of mechanical strength has already been found almost simultaneously with the safety lower wheel as a so-called diamond frame .

The term safety low wheel soon changed to Niederrad . Today, despite almost the same design, we only speak of the bicycle .

For a long time , high-wheeling remained an artistic sport , while the low-level bike or the bicycle with a diamond frame became a means of mass transport .

Development of the safety low wheel

Lower wheel with a diamond frame supplemented by a head tube (later the seat tube was added), Victoria-Werke , Nuremberg

Several manufacturers began designing "safer" bicycles in the late 1870s. The aim was to put the focus on the driver + bike backwards and lower. The prerequisite for lowering by using smaller wheels was the development of functional bicycle chains . Only with them the translation of the crank rotation into high speed for the faster running of the smaller driven wheel was possible. The seat further back, roughly in the middle of the bike with a longer wheelbase, between two equally sized wheels, further improved safety when riding. From the 1880s onwards there were numerous low-profile safety wheels on the market. Of the frame forms the set diamond (English diamond (Figure s.)) From top and down tubes and saddles and chain stay by.

The Niederrad was only accepted when it had won victories against high bikes in bike races around 1890 . In the Tour de France , which was first organized in 1903 , no high bikes were used, only low bikes. The development and spread of the Dunlop pneumatic tire , with which smaller wheels are no longer disadvantaged even on uneven ground, promoted the spread of the low wheel.

Sources and Notes

  • Penny farthing and safety bike. In: Wolfgang König (ed.): Propylaea history of technology. Networks, steel and electricity 1840–1914. Berlin 1990, pp. 443-449, ISBN 3-549-05229-4

Individual evidence

  1. ^ Wilhelm Wolf: Fahrrad und Radfahrer , Leipzig 1890, Die bibliophilen Taschenbücher, Dortmund, 1979, p. 100.
  2. ^ Wilhelm Wolf: Fahrrad und Radfahrer , p. 107.