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, like with other vehicles.
Carbide Bicycle Lamp History
Fire
The earliest bicycle lamps were oil-fueled and started to be manufactured in 1876 for the Ordinary (High-Bicycle) and solid-tired 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, often called artificial daylight but the lamps required regular maintenance.[1]
The first carbide bicycle lamp developed in the United States was patented in New York on August 28, 1900, by Frederick Baldwin.[4] Another early lamp design is shown in a patent from Duluth, Minnesota from October 21, 1902.[5] In the early 1900s, Gustaf Dalén invented the Dalén light. This combined two of Dalén's previous inventions, namely the substrate Agamassan and the Sun valve. Inventions and improvements to carbide lamps continued for decades.[6]
Electricity
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 halogen lamps and later by light-emitting diodes (LEDs).
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Halogen lights
Although these lights were originally designed for off-road use, where they were almost universal, rechargeable halogen lights became popular with commuter cyclists.
The lights used by most halogen rechargeable systems were cheap and bright, but fairly simple: they projected a cone of light (wide and narrow beam options were available) which is good for off-road use but not ideal for road use as it can dazzle oncoming road users. This is why halogen lights do not meet legal requirements in some jurisdictions.
Many systems used standard commercial prefocused optics, making a wide range of power and beam width combinations available. Most systems allowed simultaneous connection of different lamps - for example, a wide and a narrow beam for off-road riding, or a high- and a low-power beam for road riding.
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HID lights
High-intensity discharge (HID) lights were a brighter/more efficient alternative to filament bulbs prior to the widespread adoption of LEDs.[citation needed] Like halogen systems, they were designed primarily for off-road use, having rotationally symmetrical beams which cast as much light up as down. HID lamps were susceptible to damage from repeated strikes, and in many cases did not relight immediately after shutting down. Likewise, should the battery level fall too low, the lamp would shut down rather than dimming. But the longer battery life than halogens tends to negate these problems, as many riders would simply switch the light on and leave it running throughout the ride.
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Xenon strobes
Xenon strobes were an innovation in bicycle lighting; previously common in industrial applications. They were brighter than LEDs and sometimes used as rear lights.
