The 90's and earlier style BMX stems work good. They upper half is held in place with 4 allen head bolts. The one pictured above would be harder to get over the t-bar. In fact, they aren't even designed to open up that far and would probably break or become very deformed in the process.

http://www.bikepartsplace.com/images/med/31865557.jpg

Last edited by Neil; 04/19/10 08:17 PM.