I am sure others have done something similar, but for those who haven’t, I thought I would post this. I did not see a previous post concerning this procedure, but if one exists, please remove this one.
I found myself trying to replace my original headset or steering ball bearings and races with a tapered needle bearing set from All Balls.
Drifting the old races out is pretty simple, even though I boogered the tip of my big Snap On straight screw driver doing so, and drifted the lower race out sideways putting a scar in the inside of the head tube, necessitating using a die grinder to smooth out the bore before placing the new race. I also cut the old lower bearing off the steering stem attached to the lower triple tree as it was much easier than trying to drift it off.
There are two tricky parts to seating the new races. First, the manufacturer has seen fit to offer an upper race that is 2.5 mm too high or proud. It protrudes above the height of the head tube. Once you know this, it is not a problem as the flanged adjuster nut covers the oversight. Anders Wenblad, a friend who is also one of my heros, machined the inside of the nut so that it captures the bearing below it, and puts pressure on the upper surface of the bearing retainer equally and stabily. Secondly, and perhaps more importantly, the fully seated lower race position is recessed inside the head tube 7mm and change. Putting the race in so that one side is not higher than another and recessing the race in the head tube was accomplished by milling a 2 inch OD steel washer to just under 50mm( 49.8ish) with my bench grinder. These washers are about 4 mm thick so I used a second, smaller OD one which was the same thickness behind it to push the race to place, tightening 26 mm nuts on a 12mm threaded rod. I used nuts on either side of these two washers, while the other end, which sits on top of the head or steering tube, uses a couple of 2.5 inch OD washers and a third smaller one with a smaller ID with a single nut which I tighten to seat the lower race. I placed the lower first and then the upper. I got all of this stuff at the corner hardware store for under 10 bucks.
