Bicycle lighting

Bicycle lighting is illumination attached to bicycles whose purpose above all is, along with reflectors, to improve the visibility of the bicycle and its rider to other road users under circumstances of poor ambient illumination. A secondary purpose is to illuminate reflective materials such as cat's eyes and traffic signs. A third purpose may be to illuminate the roadway so that the rider can see the way ahead. Serving the latter purposes require much more luminous flux and thus more power.

Many jurisdictions require one or more bicycle lights to be fitted to bicycles ridden at night — generally a white light in the front and a red light at the back.

The earliest bicycle lamps were oil-powered and started to be manufactured in 1876 for the Ordinary (High-Bicycle) and solid tyred tricycles. From 1896 acetylene gas lighting for bicycles started to be introduced and later in 1899 acetylene gas lamps for the motor-car became popular. Their carbide lamps were powered by acetylene gas, produced by combining calcium carbide with water. The light given was very bright but the lamps required regular maintenance.

From as early as 1888 electric-powered bicycle lamps were manufactured but did not become a viable proposition until 1898. They comprised an incandescent bulb and either a lead-acid battery or a dynamo. Lead-acid batteries were replaced by dry cells and later by alkaline batteries. Dynamos improved in efficiency and reliability, recently being incorporated into the wheel hub, for example. Moulding techniques for plastics also improved, allowing lens optics to be improved and cost reduced. Incandescent bulbs were replaced first by sealed-unit halogen lamps and later by high-output light emitting diodes.

In Germany, it was illegal to use bicycles without a dynamo-based lighting system except on "racing bicycles" below 11 kg. This stimulated the market in Germany for high quality dynamos. Since 5 July 2013, a change in the law allows use of battery-powered lights.

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Wikipedia