in 1500 miles of touring (900 of that in china - gnarly road conditions) using schwalbe marathon XR tires, i have not had one flat.
the end cap DID work off my road morph G one time, I had just pushed off after a stop, heard the clink as it hit the pavement. glad I found it. this in china with presta valves! carry the adapter now...
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2009 Custom TI Frame Road Bike, all 2007 Campy Record, Campy Euros Wheelset
2009 Custom TI Frame touring Bike. S&S couplers, XTR Drivetrain. LOW granny.
2009 Performance Bicycles TI (by Lynsky) road frame, 7900 DA, 7950 DA Compact Crank, Light Niobium Rim Wheels