Which Bike Frame Material is the best for me?
The light-weight road hardtail made of carbon or the retro road bike with a frame made of narrow steel tubes – different frame materials combine different emotions, lifestyles, one can even say philosophies!
The various materials used in frame construction are characterized by specific properties. As a result, they are particularly well suited for certain purposes and less well for others. To help you in your search for your dream bike, we have compiled what you need to know about the four most common materials – carbon, aluminum, steel and titanium.
General Information about Bike Frame Materials
The frame is the heart of the bike. Like no other component, it decides the driving behavior of the wheel. Therefore, the question of the right material for the frame – in addition to a good fit – is of crucial importance. The bicycle has gone through some materials in its over 200-year history. Steel has long dominated as a material for bicycle frames. Other materials were repeatedly tested, for example magnesium, but none of them could initially assert itself against steel. It was only in the mid-1980s that aluminum frames came together with the mountain bike. The shape of the frame also changed with the new material – the thin steel tubes were replaced by more voluminous and at the same time lighter aluminum tubes. This made the frames lighter and stiffer at the same time. At that time, the artificial material carbon was already being experimented with. However, it took about 15 years for carbon bike frames to become affordable for a wide audience around the turn of the millennium. To date, carbon frames are significantly more expensive than the somewhat heavier aluminum models. They are therefore primarily installed on high-quality and high-priced bicycles, which were developed primarily for sporting use.
Titanium and wood are niches
While the mainstream of the cycling market is dominated by the three materials steel, aluminum and carbon – titanium and wood (bamboo) are niche. The history of the bicycle is virtually inseparable from wood. Wood is mainly used for styling reasons. Frames made of bamboo tubes look simply chic, but cannot keep up with other materials in terms of resilience and driving characteristics. It is different with titanium. This metal has very good properties for bicycle construction, but is very expensive. Therefore, bikes with titanium frames have never got beyond their luxurious status.
After this historical part, the question now is what factors are important for a frame. When you lift a wheel, the first thing you will feel is the weight of the wheel. When driving, the rigidity of the frame and the comfort will be noticeable. Durability plays an important role in long-term use of a bike. Last but not least, the material used has a great influence on the look of the bike.
Deciding Factors of Bike Frame Material
You can feel the weight of a wheel when you lift it for the first time. When riding, it matters when going uphill or when the wheel is accelerating. In everyday use, however, it can also be important if you have to carry your bike more often, for example to the apartment or the basement. The weight of a wheel can be influenced by the material used and by using as little material as possible. For this purpose, the tubes of the frame are kept as thin as possible. For frames made of metals (steel, aluminum, titanium), butted tubes are used for this purpose. These pipes have a smaller wall thickness in the middle part than at the ends where they are connected to other pipes. This allows the amount of material to be kept as low as possible without compromising on stability.
Weight is particularly important for sporty bikes and when the bike is carried more often. Here is a short weight ranking of the frame materials (from light to heavy):
- Aluminium / Titanium
Stiffness and comfort
Stiffness and comfort of a bike are two factors that are not immediately apparent. Only when driving over rough roads, cobblestones and curbs will you notice how comfortable your bike is. Is every hit passed unfiltered to the rider or is it dampened, swallowed? For this, the frame is the key component and the material used for bicycles is a key influencing factor.
The stiffness is similar. It is crucial for how efficiently forces are transferred to the bike. This is done using the crank and handlebars. A rigid frame in the area of the crank and chain stays ensures that the wheel can be accelerated well. In the area of the steering head bearings and the fork, more rigidity brings more precise control. Especially at high speeds (over 50km/h), the bike still feels easy to control.
At first glance, rigidity and comfort contradict each other. If a frame is very stiff, it doesn’t twist as much, the power is also transferred very well from the crank to the rear wheel. At the same time, however, this means that hit from the ground are passed on directly to the rider. Conversely, a frame swallows shocks better if it is more flexible, i.e. less rigid. Then strength tends to be wasted. Accordingly, compromises have to be made in this regard. This is done through the thickness and shape of the tubes. For example, very thin seat stays are often installed in order to achieve more comfort on the rear triangle. On the rear triangle, on the other hand, the connection between the bottom bracket and chainstays is designed to be as wide and stiff as possible in order to transmit the forces to the rear wheel without loss.
A maximum of rigidity is sought when forces are to be used as efficiently as possible. Comfort is a key factor for bikes that you use in everyday life or on longer tours. With regard to driving comfort, the materials behave as follows:
Tip: If your bike is not comfortable enough, a suspension seat post can help.
STW (Stiffness to Weight)
If you occasionally read cycling magazines, you will probably have come across the STW value in the tests there. STW stands for Stiffness to Weight and indicates the relationship between the (steering head) stiffness and the weight of the frame. The higher the steering head stiffness and the lower the weight, the higher the STW value. However, it should be noted that this value is only of limited significance. After all, a soft frame doesn’t feel better just because it’s light.
Based on the ratio of rigidity and weight, the advantages of the frame materials are distributed as follows:
The durability of a frame depends primarily on external factors. These vary depending on the intended use of the bike. A road bike, which is only used for training and then disappears again and again in the basement, is exposed to other influences than a city bike, which is used for the daily commute to work or for shopping. The different materials also handle falls differently well.
It goes without saying that a bike should be as durable as possible. The following overview refers to the resistance of the materials in everyday use. So it refers to the insensitivity to scratches and bumps:
- Titanium / Steel
Last but not least, you want to buy a bike, which not only scores with its inner values, but is also visually convincing. The material also plays a role here. As a fan of classic road bike design, you will be able to do more with the thin tubes of a steel frame than with the voluminous tubes of an aluminum frame. After all, modern aero road bikes can hardly be built from a material other than carbon.
You have to decide for yourself what material the most beautiful frames are made of – you will definitely find what you are looking!
Bike Frame Material Properties Overview
|Carbon||high||very low||very high||high|
|Steel||very low||very high||low||very high|
|Titanium||very high||low||average||very high|
You can see that choosing the right frame material plays an important role. There is no material that offers optimal properties in every respect. Which material the frame of your bike should be made of depends on the intended use of your bike. But when buying a bike, you should note that the attachments also have a great impact. For example, the weight can be corrected downwards using light attachments. Riding comfort can also be improved by adapting the add-on parts.