MCF Tubeless Valves Big Bore Hybrid MEngineered with precision and designed to deliver maximum inflation simply and efficiently, this patent pending valve sets a new standard and is the benchmark in high air flow tubeless tyre systems with a revolutionary Straight through internal design for maximum airflow fire power. Our Big Bore Hybrid offers up to 245% higher air flow than traditional Presta valves thanks to the straight through bore design. Precision CNC machined from 7075 aircraft