In early 2013, Magnesium Technology began to develop a magnesium wheel rim. After many attempts by various other manufacturers, the aim was to show that a durable rim can be made from magnesium.
The design of the profile, which is based on an existing aluminium rim, poses a considerable challenge in terms of the extrusion technology. The hollow profile has a complex geometry with wall thicknesses ranging from only 0.75mm to 2.6mm. In addition, the core cross-section has to be very accurately shaped, as an insert is placed inside it which aligns and positions the two ends relative to each other after the rim has been rounded.
The extrusion process also involves many challenges. A two-hole die was chosen, so that two profiles can be pressed at the same time. We ensure that both profiles are perfectly straight and come out of the die without significant torsion. Moreover, the core remains symmetrical inside the profile. This guarantees the flatness of the rim during rounding.
Once the rim has been rounded, bonded and provided with spoke holes and a valve hole, the rim is coated. The coating ensures lasting protection for the rim during assembly and use. It also serves as a substrate to which a finish can be directly applied. The rim is also coated on the inside, since the spoke nipples come into contact with the magnesium here. Corrosion just does not have a chance.
The whole process eventually resulted in the first successful magnesium wheel rim. In appearance, the magnesium rim is indistinguishable from its aluminium counterpart. A weight-saving of 28% is achieved, and the rim has been extensively tested. The results indicate that this is the best and most comfortable rim ever produced, and easily a match for the carbon rims available on the market.
The final weight of the wheel is similar to that of carbon. However, thanks to the shock-absorbing properties of magnesium, a magnesium wheel is far more comfortable, lasts longer and costs a good deal less.