STEEL

Hi-tensile and chromoly are the two main types of steel used the cycling industry. Hi-tensile is low carbon steel that is exceptionally cheap and used for low cost department store bike frames. Chromoly is a blend of chromium and molybdenum alloys. This is what quality steel mountain bike frames are fabricated with. Chromoly can be referred to as CrMo or 4130 in the cycling industry. The downfall of chromoly is its density. It is the heaviest (per cubic inch) of the four materials. Although inherently dense the development of butted tubes and alloy blends are allowing fabricators to build lighter frames of equal strength and stiffness. The advantage of chromoly is that it’s cheap, reliable and simple to fabricate frames with.

IS A STEEL FRAME RIGHT FOR YOU?

A rider who purchases a steel bike will likely value tube design, professional welds and frame longevity. They also see chromoly as a cost effective and classic material used in frame fabrication. Weight is not at the forefront of the purchase but a bike that will build memories for the next ten years is.

Aluminum

Aluminum is the second lightest of the materials per cubic inch behind Carbon. Today, aluminum frames are designed for an array of mountain biking’s demands. It can be fabricated into agile XC frames or built into burly DH frames where strength and durability are essential. Aluminum frames are the second stiffest in design behind carbon. Titanium and Steel can compete but the extra material and weight needed to do so usually isn’t worth the added stiffness. Because aluminum lacks in elongation, or the natural amount of stretch, designers use more material and larger diameter tubes to make the frames durable. This design process stiffens the frame but the extra material used is not a weight penalty with aluminum being so light. The cost of materials, ease to work with, and its lightweight nature make it possible for manufacturers to offer the consumer a competitively lightweight frame at an affordable cost.

IS AN ALUMINUM FRAME RIGHT FOR YOU?

Bike companies generally offer 2 to 4 different models of the same bike frame. For Example, the Giant Reign, a Trail bike, comes in a lower priced aluminum frame model and a top-of-the-line carbon fiber frame model. The use of aluminum allows the consumer to get the frame design they want at a more wallet-friendly price. The aluminum model and carbon fiber model have the same frame geometries, but the weight and quality of components may differ. If price point is the pinnacle of your purchase concerns, an aluminum frame will meet your frame geometry needs and save you some extra money to spend on higher-end components.

CARBON

Carbon Fiber is in a league of its own as a frame material. It does not behave like Aluminum or Steel because it is a composite rather than a metal. A composite is a combination of fibers and epoxy. Carbon fiber or carbon for short is composed of fibrous stands woven into a grid, layered and then bonded together with an epoxy. In the construction of a carbon frame the fibrous grid is layered around a bladder mold, pressurized and then heat-treated in a separate mold while the epoxy cures. Engineers use various fiber weaves, epoxy blends and mold shapes to fabricate robust DH frames or forgiving, ultra light XC frames. Every World Cup XC racer and most World Cup DH racers will be riding carbon bikes in 2017. Carbon is the lightest of the four materials and its complexity during fabrication makes it the most expensive. The main flaw of carbon fiber is its lack of elongation or the amount of the materials natural stretch. When carbon breaks, it breaks all at once. A dent or bend is not possible with carbon like it is with steel or aluminum. With that being the main disadvantage of carbon, engineers over build frames or use unique layup patterns in high stress areas to prevent issues. Today’s carbon frames are the lightest and strongest available, and increasingly durable to withstand the rigors of riding and the inevitable crash scenarios. With carbon’s growing popularity the prices are getting more competitive and frames are populating a broader range of bike models.

IS A CARBON FIBER FRAME RIGHT FOR YOU?

The cycling industry is extremely weight conscious and places a high monetary value on lightweight carbon fiber technology. If you see the benefits in the stiffness, vibration-damping and weight savings of a carbon fiber frame, then it is the right material for you. Carbon will continue to be a relevant material used in frame construction for years to come. The benefits of a carbon frame may not be worth the extra investment for newcomers to mountain biking. The weight savings and frame stiffness may go unnoticed because the main concern will be getting a feel for mountain biking.

Alternatively, there are frames designed for the advanced enthusiast who values the carbon frame experience. With a range of component builds and various tiers of carbon fiber models, manufactures are getting their bikes to a broader expanse of riders than ever before.

TITANIUM

Titanium is only used by a few niche mountain bike frame manufactures today. The benefits of titanium as a frame material are density, strength and elongation. This elegant material is half the weight of chromoly and has the most amount of elongation, out of the materials discussed. Titanium mountain bike frames are noted for providing a smooth, vibration damped ride. Cost and density are the flaws of titanium. Though it is the lightest of the metals, a titanium frame fabricated to be competitive in weight to carbon would be too flimsy and prone to failure to sell. Processing is other reason the material is expensive. Titanium’s strength requires advanced machining and welding methods that are more expensive than steel or aluminum. Despite being an abundant metal in the earths crust, titanium’s extraction process is intensive and another factor that drives the price up. Titanium does have a sense of elegance to it. It is a desirable material with many beneficial properties for frame construction but at the end of the day it still does not offer the lightness of carbon fiber in a weight conscious cycling industry.

IS A TITANIUM FRAME RIGHT FOR YOU?

If you are looking to ride mostly in the XC category then you will have multiple titanium frame options. For Trail bikes, options get slim, and DH bikes there are virtually none. Titanium is used primarily in XC hardtail frames. The vibration damping qualities over chattery bumps offers a forgiving ride quality for frames without rear suspension. There are manufactures that specialize in only building titanium frames. If you value using the most sophisticated metal, ride XC or light trail and are not concerned with the latest and greatest carbon frame craze, then titanium is there for you.