Magnesium Die Casting versus Carbon Fibre

In bicycle materials today the discussion is always about alloys or about carbon fibre. Everyone knows that, for the same weight, carbon fibre is much stronger than ordinary metal — but its high price sets a threshold.

People in the bicycle industry point out that carbon fibre still involves a great deal of hand work and is far less suited to volume production than magnesium alloy. It therefore consumes more cost and time and places higher demands on process control. These factors feed directly into the price of the finished product, so the end customer pays more.

On the other hand, environmental protection is a topic every industry takes seriously, and carbon fibre's environmental burden is considerable. A 2010 study published by Toyota showed that processing the raw materials for carbon fibre generates large amounts of waste gas and waste water, that further processing emits even more CO₂, and that the production process may cause respiratory illness and skin disease among workers. Discarded carbon fibre products persist in soil and water for a very long time and are extremely difficult to degrade, adding further pollution. Whether carbon fibre is really a green material therefore remains an open question.

Magnesium alloy, by contrast, is a new environmentally friendly material for the 21st century, and abroad it is classified as part of the green industry. It does not pollute the environment and its recyclability is very satisfactory.