Originally Posted by
srinath.the.man
The quill stem has the advantage of "set it, lube it and forget it" on the bearings. Atleast it is on motorcycles.
Yet with the early MtBs we saw a lot of headset loosening up problems. Enough so that even after a number of threaded headset, having additional steerer clamping within the threaded top/lock nut, were brought out another all together different design was tried and kept because the new design worked better for longer. Threaded steerers were the old standard, threadless ones with associated different stem and headset are the new standard. Andy