How to Repair Cracks in a Bicycle Frame

Many manufacturers have substituted research and development for warranty repair. In the past, bicycle companies might produce 100 prototypes and distribute them free to riders, recall them in a year and analyze them for defects. They would make design adjustments and the bike would go into production. Today, manufacturers sell a bicycle with little or no research and development, at a great cost savings. If the frame cracks during the warranty period, they fix it. If a frame cracks after the warranty period, the consumer fixes it. Bikes are made from light material and this sometimes leads to metal-fatigue cracks in the frame.

Things You'll Need

  • Safety glasses
  • Welding shield
  • TIG welder
  • Wire brush
  • Sand paper
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Instructions

    • 1

      Determine the length of the crack. If the crack has a separation in it, use a C-clamp to clamp the crack shut before welding.

    • 2

      Remove the paint around the frame crack using sandpaper. Sand the cracked area until only the bare metal is showing.

    • 3

      Disassemble and remove any clamp-on accessories or components near the crack that may be damaged from the heat of the welding torch.

    • 4

      Weld the crack using a TIG (tungsten inert gas) welder. The TIG welder produces concentrated heat that eliminates heat damage and warping by heating only the small area to be welded. The TIG welder uses an electric torch and a metal filler rod to manipulate and fuse the surrounding base metal and fill any remaining cracks with a strong bead weld.

    • 5

      Replace any components or accessories that were removed to protect them from heat damage.