ASK THE MXPERTS: TITANIUM IS NEITHER RARE NOR MAGICAL, BUT IT IS EXPENSIVE

IF TITANIUM IS SO GREAT, WHY AREN’T THEIR ANY TITANIUM FRAMES?

Lars Larsson won the 500 class at the 1971 Inter-Am series on a titanium-framed Husqvarna 400, but once the series was over, the AMA banned titanium frames.

TITANIUM IS NEITHER RARE NOR MAGICAL, BUT IT IS EXPENSIVE

Dear MXperts,
If titanium is such a wonder metal, why aren’t there titanium frames instead of chromoly and aluminum frames? Is titanium stronger than steel? Is titanium is a rare metal? Why is titanium so expensive? What is titanium anyway?

Most people like to think of titanium as a rare metal due to its high price tag. The truth is that titanium is the fourth-most abundant metal in the Earth’s crust behind aluminum, iron and magnesium (in that order). Titanium accounts for 0.62 percent of the Earth’s crust. To buy titanium in its raw form is fairly inexpensive; however, the process to isolate the metal is what raises the price tag dramatically.

Titanium is not a newly discovered metal. It was first discovered in 1791 by William Gregor of Great Britain, who named it after himself, gregorite. It was then rediscovered in 1793 by a German chemist who named the element after the Greek mythological giants, the Titans. It wasn’t until 1797 that it was found that gregorite and titanium were the same element; however, the process to isolate titanium wasn’t successful until 1910.

The most efficient way to extract titanium was discovered by William Kroll in 1937. To this day, the same process is used with some small variances. Titanium’s melting point of 3034.4 degrees Fahrenheit (which is extremely high) makes the production process energy-intensive and therefore expensive. The most common use of titanium is for axles, bolts and footpegs.

Titanium is known for its high strength-to-weight ratio. It is more than twice as strong as 6061-T6 aluminum alloy and close to half the weight of T-4 stainless steel. The metal is also corrosion-resistant, which makes it appealing to many different industries. Due to the high tensile-strength-to-density ratio, high crack resistance, high temperature resistance, high corrosion resistance and fatigue resistance, titanium alloys are used in various military applications, such as aircraft, armor plating, naval ships, spacecraft and missiles. The bulk of all titanium ore that is mined (about 95 percent) and refined into titanium dioxide, which is then used in paints, paper, toothpaste, plastics, and sunscreens for its brightness and high refractive index. Other uses are medical implants, nuclear-waste storage, jewelry, automotive applications and motorcycle racing

While titanium is the hot commodity for lightweight metals, magnesium may be the metal of the future. It is 50 percent lighter than titanium, but the process of extruding and welding the material has yet to be perfected. The grayish metal is used on many parts of factory bikes, such as clutch and ignition covers, hubs and brake calipers, to lighten the weight of the machine

The price of titanium is about double that of bronze, quadruple that of brass and 10 times that of T-3 aluminum. No wonder titanium parts for dirt bikes are so expensive. Yamaha is the only manufacturer to ever come stock with titanium shock springs, starting in 2006. They went back to steel springs on the YZ250F in 2010, YZ125 and YZ450F in 2013, and YZ250 in 2012.

In motocross racing, titanium is commonly used in axles, springs and miscellaneous bolts. Perhaps the most obvious use of titanium in motocross is the stamped-titanium Honda CRF450 gas tank. In a strange twist, Honda’s Ti gas tank is largely a fashion statement. The exact same gas tank is normally molded out of plastic, which would not weigh more but would lower the production costs.

In the FIM World Motocross Championships titanium frames were not banned. This is Jeff Smith on an all-titanium BSA in 1966. 

In the AMA Pro racing rule book, titanium is only restricted when used on the rear brake rotor. The frame could technically be made out of titanium, although there would have to be an original homologated model from the same manufacturer. According to the AMA Amateur rule book, there is no talk of titanium restrictions, save for the frame.

If you’re going to spend money on expensive titanium parts, you want to get the best bang for your buck. The best place to lighten up your bike is where the weight is unsprung. Unsprung weight is any weight that hangs below the fork or shock springs. This weight is more closely connected to the ground than the weight above it, because when you hit a bump, unsprung weight compresses into the chassis to absorb the impact. Titanium shock springs, axles or linkage bolts (all below the springs) offer the best performance gains for your money.