OS-99 CSI stem


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EF Education First Pro Cycling
Team Bahrain McLaren
Team Jumbo-Visma Cycling


The K-Force OS-99 CSI stem is 3-D forged and CNC machined from AL2014. Then it’s combined with a carbon structure using our CSI (Carbon Structural Integration) technology. CSI is a process that permanently bonds carbon to alloy to create a true hybrid product, with many of the benefits of aluminum and carbon. The final details reduce the OS-99 stems weight by using a 4-bolt sculpted AL2014 alloy/carbon faceplate and titanium hardware.


  • 3D forged and CNC machined from AL2014
  • "Carbon Structural Integration Technology
  • 41mm fork clamp stack height
  • UD Carbon Finish
  • 41mm Clamp Stack Height
  • Weight 125 grams (100mm)


Code Type
175-0317BKG OS-99 CSI ST gray 100mm 6°
175-0318BKG OS-99 CSI ST gray 110mm 6°
175-0319BKG OS-99 CSI ST gray 120mm 6°
175-0321BKG OS-99 CSI ST gray 130mm 6°
175-0322BKG OS-99 CSI ST gray 60mm 6°
175-0323BKG OS-99 CSI ST gray 70mm 6°
175-0320BKG OS-99 CSI ST gray 80mm 6°
175-0316BKG OS-99 CSI ST gray 90mm 6°


Type Stems
Technology CSI, No
Color Neutral
Series K-FORCE
Discipline ROAD
Material Carbon
Weight (gr) 126