Joined: Dec 2005
Posts: 1,383
Likes: 2
From: Boulder, Colorado
Bikes: Cinelli Supercoursa 69, Ritchey Breakaway Cross, Mondonico Diamond Extra 05, Coors Light Greg Lemond (built by Scapin) 88, Scapin MTB, Stumpjumper 83, Specialized Stumpjumper M4, Lemond Poprad 2001
Sounds like a knowledge problem. Get a pump that is made for Presta valves that has a good clamping mechanism. I haven't broken a Presta valve in years. Sounds like you are trying to use an adaptor to an old pump...Performance has good sales on pumps.