Aluminum alloy frame, generally thicker and varied in shape. The tube of the frame is a special-shaped structure, and the welded parts in the solder joints are usually larger, but some of them are smaller. Generally speaking, the welding points will be polished at the back to increase the appearance.

Generally, the high carbon steel frame is slender, and the tubes are mostly round or oval, with fewer irregular tubes and smaller solder joints, which are usually not polished.

Step 2 identify the weight

Aluminum alloy is lighter and high carbon steel is heavier. The worst aluminum alloy is also lighter than the best carbon steel. For the frame, the usual aluminum frame is 1500-2000g (excluding the front fork), while the steel frame must exceed 2000g.

Step 3 identify sounds

The sound of aluminum alloy fingers is louder than that of high carbon steel.

Step 4 do it yourself

Unplug the seat tube of the car and directly observe the seat tube of the frame. There will be oxide layer on aluminum alloy and high carbon steel will rust.

Extended data

Advantages and disadvantages of aluminum alloy frame and high carbon steel frame

Aluminum alloy frame

Advantages: light weight, optimal hardness and rigidity in a short time, easy molding and no rust. If it is light, you can draw the pipe very thin, if it is strong, you can also cut it with CNC die to make an exaggerated appearance and amazing strength.

Disadvantages: almost no elasticity, it will accumulate metal fatigue, and because of its sensitivity, portability and high rigidity, it is easy to transmit ground vibration, resulting in poor ride comfort.

High carbon steel frame

Advantages: good riding rigidity for a long time, elasticity (shock absorption) of pipes, multiple connection modes of pipes, good processability, easy welding and no heat treatment, so the cost and price are relatively low.

Disadvantages: overweight, easy to rust due to improper maintenance, difficult molding of pipes and metal fatigue.

References:

Baidu encyclopedia-bicycle rack