I recently purchased 2 of the conversion headsets. So far, one is installed, the other reserved for an upcoming project.

After a brief few minutes with a thread file on the steerer, I was able to set the bearing preload by hand. The easiest job I have ever had the pleasure of doing. Turn, turn, turn, stop...zero play, done!

Regarding the unexpected twisting: It's the top cap not being held tight enough by the quill/the quill not interfacing tight enough to fight any twisting action between wheel & handlebars. The solution as far as I can tell is to consider the recommended maximum 15nm top cap (quill bolt) torque as a a minimum torque, not a maximum.

For my own internal thought process: 12-15nm is the recommended range the left crank arm bolt torque on Shimano external bearing cranksets, so considering the quill bolt is a much larger size, I felt it was permissable to risk not more than 20nm...Not that I would recommend any more. The quill locked in convincingly tight at that torque & required a good blow with a hammer to break the friction as any quill stem properly set should.

My thoughts are the very viscous Finish Line white lithium grease I was using on any & all components may have been viscous enough to require a second or third torque at 15nm to be effectively squeezed out of the interface so that good metal to metal contact between quill & steerer could be obtained. Experiments with a thinner grease, or more conservative application of grease, &/or retorque requirements would likely provide illumination in this regard.

As I have previously dealt with improperly worked wedge-style eccentrics, I do have concerns with the threads of the quill wedge sustaining a solid whack with a hammer for future adjustments, bearing replacements, or other work. I can see the possibility in an aluminum wedge of inadvertantly blowing the threads out of a long set &/or galvanicly corroded or over torqued wedge greatly complicating future service. A steel quill wedge would at the very least eliminate any potential for future issues & buy error margin for top-cap/quill bolt torque among any shade-tree mechanics that may happen across this wonderful invention. Of course, disregard if I am mistaken. I installed mine several weeks ago & am going by memory.

Perhaps a service bullitin recommending removing quill bolt & top cap, then dislodging the wedge by way of inserting a long flat bottomed drift punch down inside from the top side of the headset to dislodge the wedge nut before servicing bearings or preload readjustment could be recommended? This would ensure the wedge bolt/nut threads never encounter impact from the necessary freeing hammer blow other quill stems encounter many times over their lives.

Anyways, them's my thoughts & I definitely would buy again. Good product.