Modern bikes are built from a variety of materials. They are strong, lightweight, and can be moulded into advanced shapes that would be impossible for a frame made from stiffer metals to achieve. Here I’ll cover the main types of bike material and which are the most popular. We’ll also consider how they are produced and what they are made of.
Aluminium and steel are the most popular materials for a bike frame, this is because of their ability to work on almost all types of bikes and for almost all types of cycling. They make good all-rounders as well as being the cheapest and most available options for a bike frame material.
Each different bike frame material will vary in its characteristics and each will determine the feel and function of your bike. The most common types of bike frame material are Aluminium, Carbon Fibre, Titanium, Steel, and Chromoly Steel.
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What is an aluminium bike frame?
Aluminium bike frames are made from an aluminium alloy, the most common material for bikes. Aluminium is used for a range of bikes, from road bikes and mountain bikes to hybrid and BMX bikes. Aluminium components are still being used on many high-end carbon fibre frames as well. You’ll find aluminium at all price points, from budget to high-end racing machines.
It’s important to note that the more expensive aluminium bike frames come with a fork (the piece of the bike that the front wheel is attached to) made out of carbon fibre, this helps to compensate for the heavier weight of the aluminium frame while helping to compromise on the cost/benefit ratio.
What is an alloy bike frame and how is it different from an aluminium bike frame?
In the biking world, we often refer to the materials that make up a frame as the main metal that is making it up (for example an “aluminium bike frame”). However, in reality, bike frames are made from metal alloys (mixes of multiple different types of metal to help give different characteristics to the frame and the bike itself). When it comes to bike frames, the term “alloy” typically means aluminium alloy, unless it clarifies otherwise.
What are the benefits of an aluminium bike frame?
The main benefit of aluminium is its low cost and low weight compared to other metals such as steel. A cheap, entry-level hardtail mountain bike will weigh around 15kg and cost under £500, with the frame only making up a proportion of that price. Not only does this reduce the upfront cost, but it also means that you can be more relaxed when using your new bike, without having to worry as much about the cost of replacing the bike if it gets damaged.
The other main advantage of aluminium bikes is how good of an “all-rounder” they are. They may not be the lightest, or the most durable, but they are average at most things, and so can make a great option for any bike, especially one you plan to use for multiple different types of cycling.
What are the disadvantages of an aluminium bike frame?
The downside of aluminium is that it doesn’t absorb impacts quite as well as some other metals – this makes it a worse option for bikepacking, touring or downhill mountain biking, (although these days you’ll see more and more aluminium full suspension bikes being used for all types of riding).
Secondly, while aluminium bikes are lighter than many of the alternatives, are still heavier than some of the other options on this list (such as carbon fibre).
What is a Carbon Fibre Bike Frame?
Carbon fibre bike frames are made from woven strands of carbon fibre which are then bound together by a resin binder. This process makes a very strong but lightweight material. This combination of a low weight but strong frame makes carbon fibre one of the best options for a road bike. Bike frames made from carbon fibre allow for a faster and easier ride, especially in road bike racing where weight is very important.
What is a composite bike frame and how is it different from a carbon fibre bike frame?
A composite bike frame is any bike made from a “composite material”. A composite material is simply a material made up of 2 separate substances that have been woven together. In the cycling world, a “composite” bike frame is almost always used to describe a carbon fibre bike frame
What are the benefits of a carbon fibre bike frame?
The combination of low weight but strong material means that carbon fibre makes a good choice for many different types of frames. A lot of people choose to use carbon fibre in order to save weight during the bike building process, and because carbon fibre is stronger than steel, it’s able to withstand a wider range of mechanical forces.
What are the disadvantages of a carbon fibre bike frame?
The main drawback of carbon fibre bikes is that they’re much more expensive than traditional steel or aluminium frames. This is not only a result of the more expensive materials involved but the fact that they’re not as easily mass-produced and thus have to be made at factories using special machinery.
Another disadvantage of carbon fibre bikes is that the material is so strong and rigid that it does not handle being flexed or bent as well as some other materials. This can cause cracks or micro-cracks in your frame which can eventually lead to your bike frame breaking completely.
What is a titanium bike frame?
Titanium bike frames are made from titanium, a very light and strong material. It is resistant to corrosion, non-toxic, and has the highest strength-to-density ratio of all metals (Which is one of the reasons it has been used in the aerospace industry for so many years).
Titanium bike frames were first produced in the 1980s but quickly fell out of fashion due to the high price of producing them. In recent years though, new production techniques have been developed that make titanium bike parts more affordable than ever.
What are the benefits of a titanium bike frame?
Titanium really lends itself to off-road ventures such as mountain biking, gravel biking, or bicycle touring because it offers great strength, durability and shock absorption while retaining a very low weight.
What are the disadvantages of a titanium bike frame?
Even with all its advantages, titanium is less popular than aluminium, steel and carbon fibre as a material Even with all its advantages, titanium is less popular than aluminium, steel and carbon fibre as a material for bike frames. This is because titanium is much more expensive than many of these options and also the fact that its main advantages are very restricted to a few key areas of cycling.
What is a steel bike frame?
Steel bike frames are made from a steel alloy of iron and carbon, with small amounts of other elements added for strength and corrosion resistance. Steel is often categorized by its “alloying” elements; For example, high-carbon steel has more carbon than other types of steel and is harder than low-carbon steel.
The main type of steel used in bike frames is mild steel (also known as low-carbon steel). This is because it’s easier to work with than high-carbon steel while maintaining most of the tensile strength, fatigue resistance, and impact toughness.
Steel used to be the most common frame material for bikes, however, in recent years this has been overtaken by aluminium. Steel still remains one of the most popular options in some biking communities such as for bikepacking or for bicycle touring.
What are the benefits of a steel bike frame?
Steel isn’t as lightweight as these other materials but may be the better option for people who ride regularly, carrying lots of gear, or for those on a budget who want an affordable ride that will last for years.
Steel frames come in very handy as they are very tough and durable, and are also much more easily repaired than other types of frames (due to how common steel bikes used to be, it is very easy to find replacement parts or someone who knows how to do repairs, even if you’re off in the middle of nowhere).
Steel also offers a high degree of comfort and compliance when compared to stiffer materials such as aluminium or carbon fiber.
What are the disadvantages of a steel bike frame?
The main downsides of steel bike frames are that steel frames can rusts if not properly looked after. Steel bike frames require regular cleaning and maintenance, which can be time-consuming and expensive.
Finally, steel is also heavier than other frame materials, with the lowest strength-to-weight ratio when compared to carbon fibre or aluminium. This can make it harder to accelerate quickly or maintain speed if riding uphill.
What is a Chromoly bike frame?
A Chromoly bike frame is effectively a subtype of a Steel frame, made up of a steel frame alloyed with two main other metals, chromium” and “molybdenum (hence the name).
It is a type of low-alloy steel that is stronger and more durable, weight for weight, than the traditional mild carbon steel used for bike frames. Chromoly is also used for making other products that require high durability, such as industrial parts, utensils and handles, but its main use is in the manufacturing of bike frames.
Due to the compromise between strength, weight and flexibility, Chromoly bike frames make a good choice for mountain bikes or other bikes that have to take on rough terrain while remaining lightweight.
What are the benefits of a Chromoly bike frame?
Chromoly bike frames are lightweight when compared to traditional steel frames, and manage to keep some of the benefits of steel frames while reducing the weight.
On top of being lightweight, Chromoly bike frames are still sturdy: more resistant to fatigue-related failures and less prone to damage caused by accidents or blows.
This stronger frame material allows the use of thinner wall tubing, giving a more lightweight frame with the same strength. It also allows the frame to be thinner and more flexible, which helps to provide a smoother and less bumpy ride.
A final advantage of Chromoly bikes, especially when compared to traditional steel bikes, is that Chromoly bike frames are resistant to corrosion and rust, unlike their traditional steel frame alternatives.
What are the disadvantages of a Chromoly bike frame?
As with most areas in the biking world, this lightweight alternative is more expensive than its steel counterpart. Because the material is more expensive, builders have to make them out of multiple pieces that are welded together at their joints; this adds weight and complexity to the process.
The other negative of Chromoly frames is that while lighter than traditional steel, it is still slightly heavier than aluminium, carbon fibre or titanium options.
What are the most popular materials for a bike frame?
We’ve seen that bicycles are made of a wide range of materials, but aluminium is the most popular and is used in more than two-thirds of all bikes sold in the United States. This is likely due to Aluminium being one of the best “all-round” materials, being cheap, with low weight, good durability and protection from rust.
We asked a large cycling community for their favourite overall bike frame material, as well as which material their bike was actually made of for each to find out cyclists’ favourite and most popular bike frame materials.
As you can see, while titanium bikes were people’s favourite overall, it was not the most popular bike when it came to which bike people actually owned! This is likely due to titanium’s high price tag (a reason we felt that carbon fibre was also underrepresented in this survey).
It is clear though, that the most common types of bike remain aluminium and steel, with aluminium being the most common type of mountain bike frame that our cyclists owned, and steel being the most common type of material for bicycle touring.
When it came to bikepacking, the results were a lot more varied, which is likely a result of bikepacking taking on many different forms, and so the material you want your bike to be made of will be very dependent on the terrain you are riding on. It also might be the result of how varied a sport bikepacking is, with many using whatever bike they already owned for their bikepacking trip.
For road biking, carbon fibre was the most popular option, this is likely because carbon fibre’s main attributes fit well with road cycling (less mechanical stresses are placed on the bike when road cycling than in other forms of cycling). Road cycling is also more common in cyclists between the ages of 20-40, which may result in a higher expendable income that allows them to purchase more expensive frame materials such as carbon fibre.
Apart from their individual advantages, aluminium and steel also have the advantage of being some of the best materials for a first or introductory bike. This is because they are so readily available, easy to maintain, and cheap to buy. Because of this, aluminium and steel bikes are likely to be more popular, as they will be the first bike many cyclists own.
Overall
As you can see, there are a wide variety of different materials that can make a bike frame. Each with its own advantages and disadvantages. While the most popular options include steel and aluminium bikes, if you have a particular sport you are focusing on (such as bikepacking), then make sure to choose the material that is best suited for the riding and terrain that you will be doing the most often.
