With so many options to choose from, it can often be difficult to decide which bike frame material to go for when buying a new bicycle.
The cycling world has developed from steel through aluminum to carbon fiber, but what has led to these changes in popularity through the eras?
Different materials all have different advantages relative to each other, but which benefits and drawbacks will have the largest effect on your ride in practice?
If you’re buying a new bike and can’t decide on the best material for you, don’t worry! We’ll answer these questions and more in this guide to give you everything you need to know about frame materials.
To cover all bases, in this article we’ll discuss:
- Carbon Fiber Bike Frames
- Aluminum Bike Frames
- Steel Bike Frames
- Titanium Bike Frames
- Bamboo Bike Frames
Ready to become a bike frame material expert?
Let’s get started!
Carbon Fiber Bike Frames
Carbon fiber is the most sought-after material for modern high-end road bike frames.
Almost every bike used by a professional cyclist in modern races will have a carbon fiber frame. First introduced as a frame material in 1986, it became the most popular material in the professional peloton by the mid-2000s.
Advantages of Carbon Fiber Bike Frames
Carbon fiber frames have one advantage that outshines the others: it’s exceptionally light.
It has a density of half that of aluminum, a third of titanium, and less than a fifth of steel.
A lighter bike is beneficial for a number of reasons. It makes climbing considerably easier and requires less power to accelerate or decelerate. Additionally, the decreased weight results in more sensitive braking and better handling.
Another advantage of carbon fiber is its strength. It has an incredibly high tensile strength, up to 3 times that of aluminum. This translates to more durability in the face of crashes, since carbon fiber will not easily deform.
Carbon fiber is also incredibly non-reactive. It doesn’t rust, and it’s very resistant to water. This is very helpful for outdoor storage or varying weather conditions whilst riding.
Disadvantages of Carbon Fiber Bike Frames
Along with the plethora of positives that can be said about carbon fiber frames, there are also a fair few negatives.
Firstly, although it is incredibly strong, it also is extremely inflexible. So although it takes more force to deform carbon than aluminum, when it does deform, it can easily crack. Any cracks in your carbon can lead to sudden and catastrophic total failure; not ideal if you’re on the bike at the time.
For the environmentally-conscious cyclist, carbon fiber is not the cleanest material to manufacture either. For every kilogram of carbon fiber manufactured, 25kg of carbon dioxide is emitted into the atmosphere. This is by far the most of any frame material.
However, the biggest disadvantage of carbon fiber is the price. Carbon fiber is extremely expensive: for a high-end carbon fiber bike, you’re looking at an investment of thousands of dollars.
Aluminum Bike Frames
The introduction of aluminum bike frames sparked a revolution in bicycle manufacturing and racing.
In the 1970s, the first prototype aluminum bikes began emerging. The majority of bikes in Grand Tours were aluminum by the late ’90s, providing a lighter and faster alternative to the century-old stalwart of steel.
Advantages of Aluminum Bike Frames
Aluminum bike frames have a number of advantages over other materials.
First of all, aluminum is light. Not as light as carbon fiber, of course, but considerably lighter than steel.
Additionally, aluminum is also non-reactive, so you don’t have to worry about rust or corrosion wearing down the quality of your bike. This also makes it safer to buy second-hand than steel, because there won’t be any hidden internal corrosion or rust which compromises the bike’s structure.
Aluminum is not as strong as carbon fiber, but it’s also much less likely to crack. This could also be a reason to choose aluminum over carbon for a second-hand bike since you might not be able to see a crack in a carbon fiber frame which will prove to be fatal very shortly.
Aluminum bike frames are much cheaper than carbon fiber and have a similar cost to steel frames.
Disadvantages of aluminum Bike Frames
Aluminum bike frames are very rigid.
This results in very little flexing and energy absorption when you are riding on a rougher road surface. For this reason, aluminum provides a much harder ride than steel, and also harder than carbon.
The environmental impact is also not insignificant, with 18 kg of carbon dioxide released per kg of aluminum manufacturing. This is less than carbon, but still much more than steel. However, regardless of the material, cycling is still miles better for the environment than driving or even any form of public transport!
Steel Bike Frames
Steel bike frames dominated the field for by far the longest time period of any bike frame material, from before the birth of the Tour de France to the advent of aluminum and carbon bike frames.
Even now, steel remains the material of choice for certain types of bikes, and die-hard vintage bike enthusiasts can still make a (moderately) convincing argument for steel over its more modern rivals.
However, there is variation in the quality of steel used for frames which results in varying strength and weight of the resulting bikes.
Arguably the most famous steel used in bike frames dates all the way back to 1935. Reynolds Tubing released a new steel alloy, called Reynolds 531, which became the benchmark for high-quality steel for frames until the 1980s.
Reynolds 531 steel is incredibly strong, meaning that the steel tubes can be rolled thinner while maintaining sufficient frame strength. This in turn makes frames made with high-quality steel much lighter than those made with low-grade steel.
Advantages of steel Bike Frames
Steel is much more flexible than any other material on this list. The main effect this has is a considerably softer, more comfortable ride.
Since the very first bikes were made of steel, and remained the most popular material until the 90s, many of the most beautiful vintage bikes have steel frames. These frames can often also be converted to be compatible with modern groupsets and other fixtures which can massively upgrade your ride, whilst still giving you that beautiful vintage frame aesthetic.
Another advantage of steel is the price. You can often pick up a fantastic vintage steel bike frame made from Reynolds 531 or 501 for under $300!
Of the conventional frame materials, steel is also the most environmentally friendly, releasing just 1.9kg of carbon dioxide per kg of steel manufacturing. Additionally, since this manufacturing happened many years ago in the case of vintage steel frames, you could consider it a sunk cost, since no new steel has been made.
Disadvantages of Steel Bike Frames
Despite all this, there are still some disadvantages to steel frames.
Firstly, steel is relatively heavy compared to modern bike frame materials. With triple the density of aluminum, it makes a noticeable difference to the power required to accelerate, and of course the handling of the bike itself (though not necessarily for the worse!).
Steel frame bikes are also susceptible to rust, making riding in poor conditions or outdoor storage very risky. Exposure to significant rain will be far more detrimental for a steel frame than any other.
Titanium Bike Frames
Titanium bikes have been around for a while and have a significant cult following. The first titanium bikes were released in the early 1970s and touted as a high-end, lighter, and corrosion-resistant alternative to steel frames.
Advantages of Titanium Bike Frames
Titanium bike frames could be considered a happy medium between aluminum and steel.
Titanium allows for far more flexing and results in a more comfortable ride than aluminum, but is also much lighter than steel. It’s also relatively strong, meaning it may be better able to survive a heavy impact than steel.
Disadvantages of titanium Bike Frames
Titanium is a rare metal that requires intense mining and expensive manufacturing. This makes titanium bike frames very expensive, and in reality, you don’t get the best value for money, relative to aluminum or steel.
Although it’s softer than aluminum and lighter than steel, it’s also harder than steel, lighter than aluminum, and far more expensive than either for them.
Additionally, manufacturing emits 8kg of carbon dioxide per kg of titanium produced. Although this is still less than aluminum and carbon fiber, it also requires more extensive mining, further damaging the environment.
Bamboo Bike Frames
This may sound bizarre, but bamboo provides an extremely viable material to build a bike frame.
First patented in England by the Bamboo Cycle Company in 1894, it was overshadowed by the introduction of tougher metal alloy bikes. However, in the modern world, there is certainly still a place for bamboo bikes.
Bamboo has been used for millennia by humans for construction purposes due to its exceptional material qualities. It’s difficult to see why these qualities wouldn’t be beneficial for bikes too.
There are a growing number of bespoke frame builders around the world turning to bamboo as the bike frame material of the future.
Advantages of bamboo Bike Frames
Bamboo is a renewable material, with a growth rate of up to 35 inches per day! Any material harvested for the production of a bike can be replenished in only a few days. Also, it’s actually a net carbon sink, absorbing more carbon dioxide while it grows than is emitted during manufacturing.
But even with sustainability put aside, bamboo offers some serious credentials as a bike frame material.
A bamboo bike frame is very light, with less than half the density of carbon fiber.
Additionally, it’s just as strong, but also far more flexible than carbon fiber bikes, resulting in a considerably smoother ride.
Of course, it is also not possible to rust but could degrade in the rain due to rot. To counter this, bamboo bike frames are usually coated in polyurethane, meaning the water cannot penetrate the frame.
Disadvantages of Bamboo Bike Frames
Bamboo bikes are not cheap. They are all hand-made, bespoke frames that require an extremely long time and high skill to craft, up to 50 hours. This of course results in a fairly hefty price tag, but you might be able to pick one up from around $700 brand new, or less second-hand.
Additionally, even though bamboo is less dense than carbon fiber, a finished bike often weighs more since to have the strength required the tubing must be thicker. A lightweight bamboo bike typically weighs between 8-10kg.
Now you know all about bike frame materials…
All bike frame materials have their own advantages and weaknesses. Choosing the right frame material is individual to each cyclist a the benefits and drawbacks of each material need to be weighed up in accordance with their specific needs.
If you’re going for the lightest bike possible, carbon fiber (or maybe bamboo) is for you. If you want that vintage aesthetic while remaining a fast and comfortable ride, steel is probably the best choice. If you want the best of both worlds, very light but also cheaper with some vintage models available, aluminum might be the one to go for!