Rene Herse x Kaisei Top Tubes


Our superlight top tubes come in Standard (25.4 mm) and Oversize (28.6 mm) diameters, with different butt lengths (long and short). 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.

Pro Tip: If you need a OS top tube that is longer than 610 mm, you can use the ‘long’ seat tube.

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