Rene Herse x Kaisei Down Tubes


Superlight tubes with Kaisei’s famous quality, in lengths and with butting profiles for all frame sizes. Heat-treated CrMo for ultimate strength and durability.

Kaisei makes the best steel tubing in the world, widely respected for its consistent quality and perfect roundness. Long reserved for the track bikes of Japan’s Keirin professionals (who race on steel bikes), Rene Herse offers Kaisei tubing in custom-drawn dimensions for modern allroad and randonneur bikes.

  • Custom-drawn to our specifications
  • Heat-treated CrMo
  • 'Short' sizes have shorter thin bellies and longer butted ends, for small frames
  • 'Long' sizes have longer thin bellies and shorter butted ends, for large superlight frames
  • Butting dimensions: see drawings
  • Made in Japan