So many questions: * Would be nice to see the original Riv installation. * Did that installation include the basket or did you add the basket? * Was the rack initially that high above the rear tire?
Additional Observation: * There is basically no triangulation in this setup, especially with the near vertical angle of the diving board. As a result fore and act movement may be a contributing factor to the lateral motion and shimmy. Suggestions: * Get rid of the basket. That only contributes extra weight very high up that exaggerates the shimmy. * Reduce the height of the rack to 1 cm or less above the tire. Will shorten the rear stays a bit. * Connect the forward stays directly to the fittings above the brake. They will be much shorter and provide better triangulation to the rack system. * Get rid of the bend in the left rear stay. Alternatively consider bending both rear stays inward as this may counteract the lateral motion. Hope you find a solution, GAJett On Thu, Nov 27, 2025, 12:13 PM tom butcherboy <[email protected]> wrote: > Beware of free advice..but. I think your rack might benefit from some > 'fore/aft' connection. it seems mostly side to side. And as the load get > taller, center of gravity rises. Your seat stay eyelets are both raising > their hands looking for work. I had a similar issue when downhill braking > and rebalancing some sort of front-end load was helpful. Tom. > > On Thursday, November 27, 2025 at 11:56:05 AM UTC-8 [email protected] > wrote: > >> Hi All, >> >> I have a 61.5 cm AHH with a rear rack installed by Riv when I bought the >> bike. The rack looks great, but I've noticed that when I have it loaded, I >> often get a front-end shimmy when I am riding fast and take my hands of the >> grips, and people riding behind me have confirmed the rack is moving a lot. >> It sounds exactly like what Paul M described in a 2024 post about his 64 cm >> Clem: >> "I also experienced a front-end shimmy if I took both hands off the >> handlebars with a loaded rear rack trunk mounted on the top of the rack". >> Exactly!! >> >> Because of the size of the frame and the way it's installed (see >> picture), my theory is that those vertical supports are very long and hence >> not so rigid and I'm getting some sort of harmonic motion (like a >> mini-version of the Tacoma Narrows bridge). Anyway, I've tried some minor >> adjustments to try to make the rack supports shorter and hence more rigid, >> but with only minor (if any success). At this point, I'm thinking of a >> couple of options: >> 1. more radically changing the attachment points for the rack to get >> those longer supports a lot shorter. This could get tricky though, working >> around the rear brake. >> 2. Removing the basket (it can go on my newly acquired 64 cm Clem L) and >> changing to a rear bag (e.g. Sackville Bagboy) that hangs from the saddle >> and hence doesn't really rest all its weight on the rack. I can still strap >> lighter stuff on the rack. >> >> I'm strongly leaning toward option #2 because I like the look of the rack >> as is and I think the behind the seat bag might look very nice. I guess >> another option is to install a different rear rack with more rigid >> supports, but again, I like the look of this rack and this isn't my bike >> for hauling heaving loads (that's be the Clem). >> >> Have others experienced this sort of problem and if so, how did you fix >> it? >> >> thanks >> >> Chris Young >> ABQ >> > -- > 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 [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/rbw-owners-bunch/15fae32a-4bd1-464d-b5a9-13b304bd8de9n%40googlegroups.com > <https://groups.google.com/d/msgid/rbw-owners-bunch/15fae32a-4bd1-464d-b5a9-13b304bd8de9n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > Guy -- 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 [email protected]. To view this discussion visit https://groups.google.com/d/msgid/rbw-owners-bunch/CAMHQv6XuTqMO%2BrWJshbJrWuwx96zSZk%3DQP8fAobxrZOou%2Boh6Q%40mail.gmail.com.
