There is a certain problem with the side view on the webpage. In fact, the side shown in the problem map is not the same. 网页上的侧视图出了一定的问题，实际上去题图所示侧面并不是那样的。
@fulin 谢谢巨佬
Added Gear Control bottom bracket.
There is a certain problem with the side view on the webpage. In fact, the side shown in the problem map is not the same.
+1网页上的侧视图出了一定的问题，实际上去题图所示侧面并不是那样的。
@fulin 谢谢巨佬
+1Added Gear Control bottom bracket.