Magnesium wheels suffer from embrittlement. Magnesium is very hygroscopic {edit see below} and suffers badly from oxidation. Which is why wheels aren't 100% magnesium. They are made of different amounts of magnesium and alloy. The more magnesium the lighter the wheel. If there is too much magnesium the wheels can even combust, proven on some early F1 cars. Most magnesium parts are surface treated, usually zinc dichromate solution which is what gives them a yellow colour. Similar to aircraft parts, however as chromium is dangerous, ala Erin Brokovich, not many places can do this treatment any more. If not correctly surface protected, white rust will create cracks in the mag wheels and they will most likely fail. This is a big problem for some campagnolo and early marvic mag wheels. I am not sure what percentage magnesium the magteks are.
Last edited by shmokica on Mon Feb 21, 2011 10:13 pm; edited 1 time in total