Seeing and being seen on bike

In the beginning there was no other choice than using flames and kerosene lamps on bicycles too. We have to say those lamps were quite elegant but pretty problematic too. They needed to be internally cleaned frequently otherwise they smelled really bad. A lot of fuel had to be burnt and it wasn’t the safest technique on a moving vehicle.

The first incandescent bulbs were made by Edison, which used a carbon filament and they were around 1% efficient in turning electricity into light. They performed better on the road but the problem with all incandescent bulbs is that they are very inefficient.

Later came a more effective solution, the on-board power generation systems. A generator (mostly we use the name of dynamo on them) is a device for turning mechanical energy into electricity. Generator-powered bicycle lights have been available for many decades. Generators have the advantage of being ready to use at any time and costing nothing to operate. The problem with the most common bottle generators and bottom bracket is that they frequently slip and fail when ridden in wet conditions, while hub generators are built into one of the wheel hubs. These hub generators were unavailable for several years, but they are going through something of a renaissance in this century, with models from Busch & Müller, Shimano. I would rather call it the rolling of the wheel of circularity.

Light-emitting diodes, better known as LEDs, are the now and the future. Basically they are solid-state devices that generate light by means of electroluminescence (electrical excitation of a solid-state semiconductor junction). The LED diodes can be used with batteries but also with generators. LEDs are highly efficient and enduring.

To supply light resources we need some batteries. These can be zinc-carbon non-rechargeable (primary) dry cells which already became available in 1898. Later on the rechargeable, or secondary batteries appeared which could be re-used many times and are recharged by applying a reverse current to its terminals. Until the 1980s almost all rechargeable batteries were lead-acid batteries. Around 1980 alkaline cells, which are primary cells, became common. More recently lithium-ion (or Li-ion) rechargeable batteries have dominated this field, likewise in bicycle lighting. These have an even higher energy density than nickel-metal hydride batteries. But the question is: what is going to be after the battery cells are going kaput? What is your capacity to do with a dead battery?

The third important pillar of the evolution of bicycle lamps is the placement of the device itself. Mounting the light sources on heavy "cruiser" bicycles were firstly popular in the USA and a headlamp would often be mounted on the front fender. A tail lamp might also be attached to a rear fender. A generator integrated with a tail lamp would clamp to a seatstay. If rear pannier bags were used, the tail lamp had to be somewhere else. Incandescent light types for trials and tribulations. The mounting and the placing could limit the quality of the whole bike light system. The console itself can restrain the quality of the luminaire. The qualities of these two are not proportionally well designed in general. Because of the bad consoles the user ends up choosing the worst place on the bike which results in covered lights and big shadows on the road. The light source can be dirty from the oily mud and you have to clean it completely at home.

Our active light sources and passive light reflectors are for different activities. We are living in a time when chemiluminescence is already on the market. This type of chemical reaction generates light as in light sticks and as used by some sort of military and emergency services. There are examples for this phenomenon in nature too, like fireflies, some jellyfish and mushrooms. Lower energy levels cause light emissions. One photon should be given off for each molecule of reactant. Some sort of bio based material could be our future and thinking of reproducing them from nature. If we think of our big data systems and their hardware needs then we can be sure that we have to think over our gadgets before we ran out of all of the raw materials.