the stem bolt is about 135mm from top of the shaft underneath the head to the bottom. theres about 4mm of unthreaded tapering, then about 40-41mm of threading. looking at the bolt, only about 15mm of threading looks like it has ever seen anything threaded onto it. So what do you think the problem is? Wrong wedge nut? Can these things even be replaced? If so, what size and where? Or should I just accept I need to buy a new stem?