Compared with aluminum alloy sprockets, what are the advantages of the steel part of the 8S MTB Bicycle Cassette Sprocket?

The steel sprocket of the 8S MTB Bicycle Cassette Sprocket is made of high-strength steel, and its tensile strength and yield strength are significantly higher than those of aluminum alloy. This material property enables the steel sprocket to withstand the frequent pedaling force impact and chain pulling during riding, especially when facing bumpy roads or steep slopes during mountain riding, which can effectively avoid deformation or breakage. The hardness of steel is much higher than that of aluminum alloy. During the friction between the chain and the sprocket teeth, the steel tooth profile is less prone to wear, and can maintain a precise tooth profile for a long time, reducing the risk of skipping teeth or falling chains.
The rigid structure of the steel sprocket makes it deform very little when transmitting torque, ensuring that the pedaling force is efficiently converted into driving force. In contrast, aluminum alloy sprockets may have a decrease in transmission efficiency due to elastic deformation under the same load, especially when sprinting, which may cause a "feeling of stepping on air". The uniform material properties of steel enable the sprocket to maintain a stable tooth spacing after long-term use, avoiding the attenuation of transmission accuracy due to material fatigue, which is crucial for mountain biking that requires frequent speed changes.
Steel sprockets can significantly improve the fatigue strength of the material through heat treatment processes, and are less likely to crack or break under repeated stress (such as periodic impact of the chain). The fracture toughness of steel is better than that of aluminum alloys. When encountering stone impact or accidental fall, steel sprockets can better absorb impact energy and reduce overall failure caused by local damage.
Although the raw material cost of steel may be higher than that of aluminum alloy, its processing technology is mature and the manufacturing cost is controllable. Aluminum alloy sprockets require precision die-casting and subsequent machining, and the comprehensive cost is higher. The wear resistance and corrosion resistance of steel sprockets significantly extend their replacement cycle, reducing the economic burden of frequent sprocket replacement, especially suitable for mountain bikes with high-intensity use.
Through surface treatments such as galvanizing, blackening or spraying with anti-rust paint, steel sprockets can be used for a long time in wet and muddy mountain environments without rusting, while aluminum alloys may accelerate oxidation in salty sweat or rain. Steel has a low thermal expansion coefficient and can maintain stable physical properties in high or low temperature environments, ensuring that transmission accuracy is not affected by temperature fluctuations.
Steel sprockets can be designed with complex tooth shapes using traditional mechanical processing methods (such as milling and hobbing), and the tooth surface can be further improved through hardening. However, the tooth shape processing of aluminum alloy sprockets is limited by material properties and it is difficult to achieve the same accuracy. Steel sprockets can be repaired by repair welding, surfacing and other processes after local wear, while aluminum alloy sprockets usually need to be replaced as a whole once damaged.