Originally Posted by alcjphil

Even if you somehow manage to install a quill stem it won't get you any lower than a threadless stem. In fact, it will be higher. A threadless stem can be installed without spacers below the stem. A quill stem still needs some way to clamp the steer tube in place which raises the stem. If your bike has a carbon steer tube you won't be able to use a quill stem at all. In addition, your bike probably has a 1 1/8" steer tube and finding 1 1/8" quill stems is going to be very difficult.