I'm with Alex - that, based on your description, the problem is still likely in the headset. Except I'd go a step further. When you said "they added a spacer because the headset had bottomed out on the threads," did you mean they added a spacer between the locknut and the threaded top race cap? Because, if so, that won't solve anything! If you're running out of threads, then the threaded top cap is the part that isn't getting tightened down far enough - not the lock nut. I would expect the mechanic to know this but I suppose that if they're strictly from the threadless headset generation, it could be an oversight on their part.
Likely what happened is that, when they faced the headtube earlier, they removed just enough material to change the length to where it mattered. Being a Rivendell, the steerer tube was probably sized to put as many threads as possible ABOVE the headtube/headset, to allow for extra spacers and increased handlebar height. (the threads that fall internal to the headtube are basically "wasted".) What you may need is a new headset with a taller stack height at the bottom race/cup portion. Worst case scenario, you may need an extended crown race - though it sounds like you're "barely" out of threads, so you'll likely be able to find something that works. Might be an excuse to get a King, which are pretty tall. Or, you could kill two birds with one stone, and look for a tall needle bearing option, instead. just a theory, but looking forward to hearing what you figure out in the end On Wednesday, August 24, 2016 at 10:19:49 AM UTC-6, Alex Wirth- Owner, Yellow Haus Bicycles wrote: > > If it were me, I would dissassemble the headset and inspect not only the > cups/headtube but also the fork crown/crown race. Dollars to donuts, based > on your description, one or both of those surfaces isn't mating correctly. > > On Tuesday, August 23, 2016 at 12:02:58 PM UTC-4, Tony McG wrote: >> >> From the beginning: The original owner purchased it as a frameset in '99 >> because at the time, the future of the Atlantis was questionable. He built >> the bike and never rode it because he found a Waterford that he liked >> better. I bought it barely used a few years ago and have put a few thousand >> miles (mostly gravel) on it. The headset would never stay tight no matter >> how hard I dared wrench on the locknut. I took it to a LBS and they removed >> the headset and machined the frame so that the headset would fit better. I >> rode it for a year, and I still had problems with it loosening. I then took >> it to another LBS and they installed a spacer (seems like the headset might >> have bottomed out on the threads???). I now have a tight headset, but >> I also have a shimmy when I let go of the handlebars. I used to be able >> to ride this bike without hands at any speed, but now it wobbles, even at >> 10 mph. I don't have any load on the bike except a small seatbag for >> tubes/tools, and the tires are the same Soma Cazadero from last year. >> >> Any suggestions on what might be causing the shimmy or how to fix it? >> Shall I replace it with a NeedleBlasteur from the Riv site and see what >> happens? >> > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at https://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.