Originally Posted by
Andrew R Stewart
I prefer the twin holed chucks VS the "smart" single holed ones. But at home I use a dedicated PV chuck (many year old Zefal Double Shot) and the damsel in distress adapter for SV. Andy.
Every twin-holed head I've used a lot has eventually refused to pump, because air is going out the wrong hole. Sometimes that's a "it's broken" failure, sometimes it's just whatever magic that's supposed to send air through the path of most resistance has not worked. Never had a single holed head fail that way....