There seems to be a lot of buzz around carbon fiber mountain bike frames these days but there’s another frame material you may not be familiar with: magnesium. Yep, it turns out magnesium works pretty well for mountain bike frames and even components like saddle rails, bar ends, and brake levers. While building a MTB frame out of pure magnesium would be impractical at best and flammable at worst, most magnesium frames are made from 90-95% magnesium (more good info here). Magnesium is the lightest machineable metal and is known for its “high damping capabilities.”
Paketa makes a magnesium MTB frame called the Wac Corporal they claim is “stronger than carbon fiber and aluminum with the comfort of titanium.” Paketa also says magnesium has the highest strength to weight ratio of any frame material, a claim we find a little misleading. In truth the Wac Corporal frame weighs between 1500 and 1900 grams while a quick check of carbon frames turns up many weighing well under 1400 grams.
Most sources we found agree that magnesium frames are stiff and responsive which means it’s a great material for building XC-style racing rigs. Magnesium should also hold up better to repeated impact than say carbon fiber as it is less likely to develop fractures over time.
Pricing for magnesium frames is on par with carbon fiber, though the prices for carbon seem to be dropping as adoption increases. The Wac Carbon X.9 build is priced at $4,400 which isn’t cheap but at least it’s in the ballpark.
Somehow I doubt magnesium mountain bike frames will become mainstream anytime soon but you never know…