The most are iron frames, but iron frames are also divided into chromium molybdenum steel, high-strength steel, ordinary steel, etc. Frames with other components added to the iron. After these other components are added, they can be made into thinner pipes. Makes the overall frame lighter. On the basis of not reducing the strength, there are frames using materials other than iron, such as aluminum alloy materials. In bicycle races, there are frames made of titanium and carbon fiber materials.
Frame and height reference data:
14 inch-150-160 15 inch-155-165
16 inch-160-170 17 inch-165-175
18 inch-170-180 19 inch-175-185
20 inch-180-190 21 inch-185-195
Before 2009, almost all mountain bikes were 26 inches. Until 2009, a car company developed the world's first 27.5 inch/650B mountain bike in Washington, USA. Since this model has the best handling, stability, safety and performance of mountain bikes, a new wheel diameter revolution in the bicycle industry has officially arrived, and major brands have followed suit and developed vehicles of this size. 27.5-inch/650B vehicles have gradually become mainstream products in the bicycle market