Ok guess I didn't find a airhead guru .steerer tube is 1-5/16" or 3.4 mm O.D , it has a tapered collar between steer tube & inside stem /handlebar unit . You tighten down a collar on the inner tapered fitting ( special Klein wrench ) this is a compression fitting . Odd thing is fork didn't come off frame after I removed all these fittings even lightly tapped down on it .dont understand how it stays on ( unless its pressed in )???

cheers