On The Pedals
By Jason Giacchino

The Frame Game

Ah trendy metals, what a concept to study. If I grabbed your attention with that then you are either a scientist or a mountain biker. Our sport is one of few that places a great deal of emphasis on frame material. Perhaps with good reason too. The frame after all is the skeleton of the bicycle and its physical attributes are credited with the entire unit’s strength, weight, rigidity, and longevity. I find myself getting caught up in the hype on occasion but have to remain level headed by realizing that my trusty aluminum based steed will outperform my abilities in most any given situation.

There is nothing new about frame designers and customers going nuts over the material used therein. In fact riders placed even more emphasis on frame material in the rigid bike (suspension-less) era. Let us bypass the very early bicycle days when frames were made of wood (of all things) and then later out of iron and begin in the recent past. The metal of the moment on early purpose-built mountain bikes was chromoly or chromium-molybdenum steel. The range of low alloy was used quite extensively to form and shape frame tubes on account of its high tensile strength and ease to weld.

Chromoly’s days at the top of the ladder would soon fade to the hype of aluminum used as a frame building material. Aluminum was noted for its ability to resist corrosion and its light weight. The rigidity of the material sent designers scrambling to compensate with pivot and suspension designs to offset the bone-jarring ride.

Development didn’t stop there. It wasn’t long after that the metallic element titanium came on the scene. It fit right in to the mountain bike persona where weight reduction is critical while maintaining high strength and rigidity. The metal is typically too expensive to make marketable to the general consumer market but holds court on high end products such as custom-built frames. An even rarer material coming into its own is use of the chemical element scandium which has very few commercial applications. If it were more common, the aircraft and space craft industries could benefit greatly. However, as it stands, scandium keeps pretty exclusive company within the handgun, lacrosse stick, and yup, you guessed it- bicycle frame consumer industries.

I don’t need to elaborate on the recent surge in popularity of carbon fiber as the uber-frame material of choice. The process involves weaving long thin filiments of carbon that are then coated in acrylic. Unfortunately with such demand comes decreased supply. Since approxiately mid-2005 the supply of carbon fiber fabric has been in steady deline. Some attribute this to the mass orders of the material for military ot aviation industries which take top preference over end-consumer use. Even so companies like Ibis, Specialized, Trek, and Scott have managed to score enough of the stuff to create some pretty wonderful designs.

So what does this range of materials have in common besides high-tensile strength and low-weight? Nothing other than the fact that the rarer the material, the most lust it generates at the trail-head. Who says you can’t put a cost on the coolness factor? Considering that throughout time there have been frames built of everything from bamboo to PVC pipes, only the strong survive just like in nature. Based on the sheer number of questions we receive here at MBT each month about carbon fiber frames and components, I’m left concluding that the hype of the latest, greatest material is gripping the world. If you’re like me you can’t help but wonder what’s next on the horizon when carbon fiber goes the way of chromoly and more importantly, why didn’t I pay better attention in chemistry?

Questions? Comments? Love letters? Send 'em to Editor@mountainbiketales.com.