This is all consistent with what I'm seeing (which is maddeningly variable). Saturday I had the AHH working with no shimmy by switching to using the Bagboy hanging from the seat instead of strapped to the rack. Monday I had the Clem working with no shimmy with a load on the rear rack very similar to loads that have caused problems on the AHH. Yesterday I rode the Clem with what I thought was a nearly identical load (same bag in back basket, same contents, even riding the same route), but somehow the shimmy showed up! It seems that small differences in amount and distribution of load can make all the difference. Peter's example shows that perfectly.
I'm thinking that bigger frames are more prone to this, but that's just a guess as I don't have shorter bikes to test the theory. Have people with smaller frames also had these problems? Chris On Wed, Dec 10, 2025 at 2:15 PM Bill Lindsay <[email protected]> wrote: > That's a solid experiment, Peter, and your observation is consistent with > the math of mechanical resonance. If a bike shimmies and one wants to make > it stop, add some weight, remove some weight, or move some weight around > and try again. That's not the only possible remedy, but it's the simplest > recommendation and ought to be effective the vast majority of the time. > > Bill Lindsay > El Cerrito, CA > > On Wednesday, December 10, 2025 at 12:28:45 PM UTC-8 [email protected] > wrote: > >> Back in the pre-cambrian epoch, I did an experiment. I took a pack of >> SRAM chains, ten to a pack, and put it inside the rack-top pack on my >> touring bike. I placed it at the rear of the pack, and put a down vest at >> the front of the pack. The bike shimmied horribly. The bike was unrideable. >> About 50 yards down the road, I stopped and moved the chains to the front >> of the bag, and the down vest at the rear. There was no shimmy. It's all >> about weight distribution. >> >> On Mon, Dec 8, 2025 at 1:41 PM Patrick Moore <[email protected]> wrote: >> >>> Just a thought, but with a large Homer frame and a sub 2” tire, you >>> might want to see if your large Homer has enough clearance between >>> underside of saddle and top of rear tire to accommodate a Bagboy without a >>> support. Me, I like transverse saddlebags precisely when they don’t need >>> supports; if I use a rack, it’s to accommodate panniers which have much >>> more volume and on/off flexibility. >>> >>> Perhaps some added stiffening — I’ve got some spare Coroplast — would >>> keep the load off the tire. >>> >>> Here’s a 30 lb load in a Medium Sackville circa 2010 with plenty of >>> clearance over rear tire and no support or even a cinch strap around the >>> bag. And, the bag was mounted on a home-made QR bag mount that put the bag >>> an inch or so lower down compared to strapping it directly to the >>> saddle.Granted, 26 X 1.4” wheel (~25” tall) on a 58 cm c-c frame (that 2003 >>> RBW Curt), but I think that modern Sackvilles have been improved for even >>> better tire clearance, and your Homer is considerably bigger than the Curt. >>> >>> [image: image.png] >>> >>> -- >>> >> 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/CALuTfguVRBziz5M6n0EtxYShx%2B-C9y252teiOfJyLigW_J5mYw%40mail.gmail.com >>> <https://groups.google.com/d/msgid/rbw-owners-bunch/CALuTfguVRBziz5M6n0EtxYShx%2B-C9y252teiOfJyLigW_J5mYw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> >> >> -- >> Peter White >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "RBW Owners Bunch" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/rbw-owners-bunch/G8tosK9y08k/unsubscribe > . > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/rbw-owners-bunch/ddb83cd5-9437-44f5-8d4e-20ebd05ebbe5n%40googlegroups.com > <https://groups.google.com/d/msgid/rbw-owners-bunch/ddb83cd5-9437-44f5-8d4e-20ebd05ebbe5n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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/CAC_3U-1MGj5NiV9EoRZ48QEVr4_Qty7_8qSyWEM%3DBUOaVkqmYQ%40mail.gmail.com.
