Revolutionising Alloy in the Bike Industry

The Carbon vs Alloy Debate: A Modern Perspective on Bike Frame Materials

When I started exploring launching my own bike brand - Hosking Bikes - the first thing I did was speak to as many people in the industry as possible. I had conversations with Executives at numerous bike brands, from boutique brands hand making bikes to established players in the industry. Their advice, “You need somewhere between $300,000 to $500,000 upfront to develop your moulds.” It occurred to me that the industry's major players, commonly referred to as the "big 5," might be utilising carbon as a defining factor to safeguard their market dominance.

Undoubtedly, one of the major barriers to entry for new bike brands centres around the substantial upfront costs tied to manufacturing carbon frames. Through aggressive marketing efforts, established brands can not only highlight carbon-framed bicycles as superior but also reinforce the perception that they epitomise innovation and ‘unrivalled’ performance.

Their strength pushing this position has made it challenging for aspiring bike brands to overcome the significant financial hurdle associated with entering the market. The scarcity of new entrants has allowed existing companies to drive prices through the roof and made it impossible for the vast majority of the community to participate in the sport. Addressing the problem requires a different way of thinking. It demanded that I ask the question: “Is carbon fibre the only way forward? Or is that the way they need us to think to keep control of the industry?”

I raced professionally for 13 years. I won some of the biggest races in the world. I’m a Commonwealth Champion, I have won sprints on the most iconic boulevards (including the Champs-Élysées), and have more professional wins than any of my Australian contemporaries. It would be a very small group of the population that have more experience than I do on a variety of the highest priced bikes in the world.

I know what a good bike feels like. I understand the almost ingrained preference for carbon fibre. But I have taken the time to ask, in 2024, does carbon fibre still reign supreme?

Introduction

While carbon frames once held a clear advantage over their alloy counterparts in terms of weight, responsiveness, and efficiency, the landscape has evolved. Modern advancements in alloy frame technology have removed the gap, challenging the long-standing notion that carbon is unequivocally superior. In this article, we'll delve into the changing dynamics of the carbon vs alloy debate, exploring how contemporary techniques have redefined the strengths of both materials.

With that in mind, carbon bikes remain the only choice available if you want to ride a bike like people in the Tour de France. For that honour, you’ll get to pay a high premium to do so. However, gone are the days where carbon actually provides much in the way of an advantage over alloy as a material for building bikes. Generally, alloy frames can weigh the same as their UCI-compliant counterparts, be as responsive, as efficient, and more comfortable.

Pros and Cons of Alloy vs Carbon Frames

Alloy Bike Frames

Before carbon fibre became more readily accessible to cyclists, aluminium was one of the most common frame materials. The material is lightweight, stiff, affordable, and easy to work with. It was alloyed with other metallic elements to increase the strength and durability.

Alloy bike frames are commonly engineered for reduced weight through a process known as butting. This technique involves strategically removing excess material from the interior of the frame tubes, essentially thinning them where maximum strength is not required. The outcome is a bike that is 1-2 kgs lighter, offering enhanced compliance and responsiveness.

Following the shaping and butting of the tubes, they are meticulously joined together through TIG welding. Subsequently, the frames undergo heat treatment to further optimise their strength.

Carbon Bike Frames

Carbon fibre is fundamentally a composite material, featuring a plastic matrix reinforced with exceptionally robust fibres. Initially designed for aerospace applications demanding a delicate balance between weight and strength, the material boasts an extraordinary strength-to-weight ratio. Surpassing steel in tensile strength, carbon fibre also exhibits remarkable rigidity.

This composite material undergoes a transformation into bicycle frames through a combination of moulding and heat processes. Manufacturers employ diverse techniques in crafting these frames, ranging from bonding individual carbon fibre tubes with specialised adhesive inserts to employing advanced modified monocoque construction in high-end models. In the latter, the head tube, downtube, top tube, and seat tube seamlessly form one continuous piece.

The construction of carbon frames exhibits considerable variation, encompassing factors such as the type of resin utilised, layer thickness, construction style, heating methods, fibre orientation, carbon fibre grade, and the density and types of fibres employed. These intricacies collectively influence the durability, stiffness, and weight of the final frame product.

The entire carbon fibre manufacturing process is incredibly costly, demanding a substantial initial investment. This financial hurdle is a key reason why many bicycle companies, upon transitioning to carbon fibre, opt to discontinue working with alloys. It is also why many carbon frames come from the same factories and moulds.

Alloy vs Carbon Fibre: Weight, Efficiency, Comfort, and Cost

Frame Weight

Forty-nine years ago, when the first carbon fibre bike was introduced, it was celebrated for being ‘feather-light’ and providing a significant edge in uphill climbs. Major brands invested heavily in carbon fibre manufacturing and marketing. However, things have changed over the subsequent 50 years. The UCI introduced the minimum bike weight of 6.8kg in 2000, limiting carbon’s weight advantage. Modern alloy bikes now match carbon counterparts in weight without compromising comfort or control.

Efficiency and Responsiveness

Modern alloy frames match the responsiveness and efficiency of carbon frames due to advances in alloying, tube shaping, and precision engineering. For high-quality bikes, ride feel between carbon and alloy can be indistinguishable.

Comfort

Frame geometry and tube shaping now allow alloy frames to dampen vibration effectively. Riders increasingly report alloy and titanium frames are just as comfortable as carbon, challenging long-held assumptions.

Durability and Safety

Carbon frames can fail in crashes or travel without warning. Alloy and titanium offer higher durability and robustness, making them safer choices for long-term use.

Cost

Alloy frames are significantly more affordable than carbon. For example, a 7.65kg 2024 Trek Madone SLR9 with SRAM RED costs ~$21,999, while a comparable 7.82kg alloy HOSKING HD4 with SRAM RED is ~$8,600.

Conclusion

As the cycling industry evolves, the gap between carbon and alloy frames has narrowed. Modern alloy manufacturing techniques have elevated frame performance, challenging the notion that carbon is inherently superior. Carbon frames still hold some advantages, but alloy frames now offer comparable performance, durability, comfort, and a major cost benefit. The era of unquestioned carbon dominance is fading, reflecting a more balanced landscape of bike frame materials.