Rethinking Carbon: Revolutionising Alloy in the Bike Industry

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 of Alloy Frames	Cons of Alloy Frames
Responsive when riding No vibrations Less expensive Safer for riding and travelling More durable Made of recyclable materials Can be mounded in almost any way	Not available below UCI compliant 6.8kg requirement ‘Ick’ factor Not readily available
Pros of Carbon Frames	Cons of Carbon Frames
Offered by larger brands Can be seen in the Tour de France Carbon does not fatigue (much) Responsive when riding Carbon is repairable Can be made lighter than the UCI compliant 6.8kg requirement with relative ease No corrosion Can be moulded in almost any way	Safety can be an issue because carbon frames can fail without warning if they are compromised Bad for the environment Break easily if components are overtightened Can crack from light impact in crashes or travel More expensive

 

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. The considerable upfront expenses associated with carbon fibre production often steer manufacturers away from alloy-based alternatives once they have made the transition to carbon.

Alloy vs Carbon Fibre Bike Frames

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. From that point on, major brands invested heavily in carbon fibre manufacturing and marketing. However, things have changed over the subsequent 50 years.

Notably, the Union Cycliste Internationale (UCI) introduced the minimum weight requirement for bicycles used in professional road racing in the year 2000. The rule was implemented to address concerns related to safety, fair competition, and promote innovation in the industry. The minimum weight for a road bike, including all its components, was set at 6.8 kilograms (approximately 14.99 pounds). This requirement limited the advantage carbon fibre once had in terms of strength to weight ratio. Now, half a century after carbon was first used, we’ve reached a tipping point where metal alloys can be used to build frames that match the weight of their carbon counterparts without compromising on comfort, responsiveness, or control.

Most importantly for consumers, metal alloy bikes cost ~half as much per kilogram as their carbon counterparts.

Efficiency and Responsiveness:

The notion that carbon frames inherently offer superior efficiency and responsiveness is now being challenged. The advantages once afforded to carbon fibre by its inherent strength to weight properties have vanished.

Alloying is the process of combining elements, typically metals, to create new materials that have new properties. It allows for the customisation of material properties to meet specific requirements for different applications. This process has advanced considerably over 50 years since carbon fibre was introduced to cycling and with advancements in alloy frame design, and precision engineering, modern alloy frames match the levels of responsiveness and efficiency of carbon counterparts. In terms of ride quality, the two substances, when high in quality, can be indistinguishable.

Comfort:

While carbon frames have often been associated with a smoother and more comfortable ride, the two materials are often indistinguishable. The ‘feel’ of a bike is characterised by frame geometry and tube shaping. While carbon frames are now introducing vibration-dampening inserts to overcome the vibration that comes with the inherent stiffness of carbon fibre, metal alloys have been developed to suppress and dampen vibration.

Cyclists are now finding that alloy, and more recently titanium, frames can provide a comfortable and enjoyable experience, challenging the long-held belief that carbon is inherently superior in this aspect.

Durability and Safety:

In 2023, while testing out prototype models on the American criterium racing scene there was an inevitable high-speed crash on the final corner.

One of the enduring advantages of alloy frames is their robustness and durability. Carbon frames, while strong and reliable, can be susceptible to damage from impacts, knocks during travel, and crashes.

Titanium and alloy, on the other hand, withstand such stresses better, providing a more durable and safer option, especially for riders who prioritise longevity, security, reliability and resilience over what might only be marginal weight gains.

Cost:

One undeniable advantage that alloy has always had over carbon is affordability. Carbon frames, with their intricate manufacturing processes and expensive materials, come with a higher price tag.

The cost of a 7.65kg 2024 Trek Madone SLR9 with SRAM RED is ~$21,999. While a comparable 7.82kg alloy HOSKING HD4 with SRAM RED is a (relatively) modest ~$8,600.

Conclusion:

As the cycling industry continues to evolve, the once-clear distinctions between carbon and alloy frames are blurring. Modern manufacturing techniques and innovative design approaches have elevated alloy frames to new levels of performance, challenging the conventional wisdom that carbon is inherently superior. While carbon frames may still hold certain advantages, it is apparent that alloy frames have claimed their own advantages. The era of carbon dominance is fading, making room for a more nuanced and balanced perspective on the ever-evolving landscape of bike frame materials.

Which, masterfully, is one of the main reasons that the UCI introduced a minimum bike weight requirement. To drive innovation in the bike industry.