I'm overhauling a friend's Cannondale 3.0 that his brother gave him, and replacing the Dura-Ace 120mm quill stem (which is beautiful) with a Nitto Technomic so he can have his bars a lot higher. The D/A stem was made by Nitto and has a unique design; the bolts for both the quill expander and the handlebar clamp are hidden and recessed, accessible after removing a cap that screws in at 45-degree angle on the top/back of the quill stem. For pictures of this model stem, see the first few shots on Peter White's stems page or just look at this shot:
Getting the bar out was easy, but I've not been able to get the stem out of the bike's steerer tube, or even get it to loosen. The expander is the "classic" sort that's not a triangular wedge, that sometimes can get stuck and needs to be tapped out with a punch or something. Here's a picture from Sheldon's site showing the diff between a wedge and an expander. The D/A stem has the expander design.
But my problem doesn't seem to be that the expander is just stuck in the bottom of the quill and needs to be tapped out. Here's what's going on in my situation:
- I loosened the bolt into the quill-expander, but the stem doesn't loosen in the steerer tube
- if the expander were stuck in the bottom of the quill, I would expect that unscrewing/loosening the bolt would raise the bolt up
- however, when I loosen the bolt that goes into the quill-expander, by turning it counter-clockwise, the recessed bolt actually becomes further recessed.
- starting from as-far-as-it-can-go in the clockwise (typically: tightened) direction, I'm able to turn the bolt six and a half turns counterclockwise, and then can't turn it any further. It feels as if it got tight in the opposite direction.
I'm trying to make sense of this data, wondering what's going on. Is the expander reverse threaded? (Unlikely, as there's be no reason for reversing, and when I got the bike it was tightened all the way in the normal-threaded direction of tightened all the way.)
Does anyone have a sense of what's going on with this bolt? I'm assuming the quill stem is just frozen inside the frame's steerer tube, but I want to figure out any uniqueness about the stem's design before I start treating it as if I know fully what's going on.
Thanks for any help.