Bicycle Measures of light output

Three units are used to measure light output. Manufacturers do not always quote the most appropriate figure—for example, watts are commonly quoted, but wattage alone is a poor measure since (a) it reports the consumption of power rather than the output of light, and (b) lamp optics will significantly impact the portion of the light which is delivered where it is needed Continue reading “Bicycle Measures of light output”

Output and optics of Bicycle Power supply

Dynamos are generally limited to 0.5 A output, nominally 3 W at 6 V, although 12 V dynamos are available and the best nominal 6 V hub dynamos can produce 6 W at speed, as detailed here (a bottle dynamo is likely to slip if run at twice the nominal power, a hub dynamo does not have this problem). A dynamo behaves as a constant-current device Continue reading “Output and optics of Bicycle Power supply”

Police bicycles

Bicycles intended for police bicycle patrol are outfitted with special colored lighting, generally blue and red, to alert the surrounding public of the officer’s presence. These lights can flash in a variety of patterns, sometimes supplemented with a siren, to help the officer make his or her way through crowded streets or sidewalks in case of emergency. Continue reading “Police bicycles”

LEDs for Bicycle Rear Lighting

Most LED lights will work in either flashing or steady modes. Flashing lights have been shown to be three to five times more visible than a steady light of equivalent brightness. But it has been found that people tend to underestimate the distance to flashing lights and that drunken drivers are attracted by them, and there is evidence that they are harder to place than a steady light. Continue reading “LEDs for Bicycle Rear Lighting”

LEDs for Bicycle Front Lighting

Cyclists who only occasionally ride at night may opt for an inexpensive LED front light and rear LED flasher. Red or yellow LEDs suitable for use as rear lights have been available for many years. Recently, white LEDs which satisfy the requirements for a front light have come on the market, and some jurisdictions have made or are considering making these legally acceptable. Continue reading “LEDs for Bicycle Front Lighting”

Bicycle Lighting Legal Requirements

Under the International Vienna Convention on Road Traffic (1968) of the United Nations, a bicycle is a vehicle. Article 44 of the Convention stipulates that: “Cycles without an engine in international traffic shall: (c) Be equipped with a red reflecting device at the rear and with devices such that the cycle can show a white or selective-yellow light to the front and a red light to the rear.” Continue reading “Bicycle Lighting Legal Requirements”

Electrical system of Bicycle lighting

Batteries, either rechargeable or disposable, are often used to power electric bicycle lights. For bicycle touring, commuting or if battery operation is otherwise unwanted an electrical generator, or dynamo, may be used. (While “dynamo” generally refers to a generator that produces direct current with the use of a commutator, cycling usage normally refers to an alternating current magneto.) Continue reading “Electrical system of Bicycle lighting”