Magnesium Alloy Wheels in Cycling: Present and Future

There are more than 200 magnesium alloy brands worldwide, which by chemical composition fall into about 30 families — some ten wrought alloys and more than twenty casting alloys. The material is used mainly in the automotive, electronics, aerospace and aviation industries; die-cast magnesium has been used to reduce vehicle weight for 70 years. In cycling, however, its application is still relatively new.

For most riders the best-known magnesium bicycle component is the lower leg of a mountain-bike suspension fork — a hot topic that every fork brand has already launched and continues to develop. In fact the application of magnesium to frames, wheelsets, pedals, stems and seat posts is also a direction the industry's leading engineers are actively exploring.

Mention a magnesium wheel and people immediately think of the heavy, garish integral wheels sold in small bike shops, and they react negatively. In reality the use of magnesium in conventional rim profiles holds great promise. One well-known Taiwanese bicycle brand has already spent five years researching magnesium rims, and teams on the mainland are moving even faster. The magnesium rims now under development weigh 270 g, against a current aluminium minimum of 360 g — 90 g lighter. The product is still in testing and has reached its fourth batch. Optimistically, production-ready rims should reach riders within one to two years, and they are certain to set off a new wave of change in the bicycle industry; further magnesium applications in other components will then follow.

Because magnesium satisfies the three critical requirements of light weight, high strength and strong vibration absorption, its use in bicycles will inevitably move towards mid- and high-end products. Once the remaining challenges of colouring and anodising are solved — so that magnesium can be as colourful as aluminium — and processes continue to improve, quality rises and costs fall, this green material will certainly come into its own.