The revised steering stem setup is coming along nicely. The GS500E steering stem is a snug slip fit into the GS650L lower triple clamp. I mocked everything up, and I just needed to make a couple of tweaks to get it set up.
The bearing-to-bearing distance in the frame is just slightly short for the stem (just a few millimeters). So, I chucked up the stem in the lathe and extended the diameter where the upper bearing fits further down the shaft a bit, to ensure the bearing has room to float once everything was properly adjusted. I also had to undercut the area at the end of the threads, so the nut won’t bottom out, and can travel past the end of the threads slightly if needed. (No criticism of the turned surface, please. I bought some new carbide tool tips off Amazon and they are utter crap.)
I was more liberal with the increased travel than I needed to be—about half the thickness of the bearing—but there’s really no functional downside to that. One reason I did this was that I mocked up the fit using a plastic analog in place of the bottom bearing. I didn’t want to press the bearing on yet, since the stem has to be welded up first, and I also need to make a steering stop adapter that will have to go on the shaft first. I made this HDPE as close as I could to the correct dimensions, but inaccuracies creep in when you do things like this. It would be a total bummer to get the whole thing welded up (at which point I won’t be able to fit the stem in my 8″ lathe), and then discover at that point I didn’t take enough off.
Next step is to re-weld the stem to the lower clamp. I will be dropping the assembled forks by my local welder this afternoon, and he should have the job done within the week.