1. 1. First of all, the frame. The overall frame strength is the most important standard for a bicycle, and it is also the safety guarantee for riding. A good frame needs to be welded by reasonable mechanical application design and corresponding materials. Here, the welding method of the frame is mainly mentioned
At present, the welding methods of frame are fish scale welding and flat welding
The standard of fish scale welding is:
Weld bead width 7-8mm, 9-11 pieces per inch, clear, full, no pinholes, sand holes, false welding, etc. the ending point should be placed at 5 or 7 o'clock
Weld bead standard for flat welding:
The standard width of flat welding bead is 11-13mm, and the surface shall be uniform without pinholes, pores, undercuts, false welding and other phenomena.