Update on the research front. In the next round of testing I put the identical load on a different bike.
I loaded my 56cm Bombadil with the trunksack small on the Nitto Mini front. I moved the Nitto R-14 rear and the loaded Saddlesack Large over to the Bombadil. The Bombadil does shimmy with that load. But it is at a much higher frequency and a smaller amplitude. The amplitude was almost small enough to just ignore. It also happened at a somewhat higher speed. More notes for the notebook. On Dec 20, 10:59 am, William <[email protected]> wrote: > Yeah, I've read that article. What "light" were you referring to? > > In that article he definitely makes himself look smart by describing > 'nutation' which is a term that 99.9% of his readers don't know. He > describes that as a driving force for why bikes shimmy, but has only > guesses for why bikes don't shimmy. He says the bikes he built don't > shimmy, and after the fact guesses why they don't. He also has > specified and implied things to try if your bike does shimmy, but just > like anyone else, he can't specify a combination of things that will > yield shimmy. > > As a group, these experts all seem to regard shimmy the way any of us > would. It's an unpleasant attribute of a bike that you'd just like to > have go away, so you can resume enjoying yourself on your bike. Just > change stuff and expect that eventually you'll find a configuration > that behaves more like you want. If you find such a configuration, be > happy and ride. If it comes up again, repeat the process. The > experts with whom you consult might have their own pet remedy to try > first, and take it for what it's worth, an educated guess. > > For my experiments, I've moved to loading my Bombadil with bullmoose > bars with the identical load that the shimmy-Hillborne had. Nitto > Mini and small trunksack in front. Nitto R-14 and Saddlesack Large in > back. I'll ride that around (weather permitting) and see what comes > of that. > > On Dec 17, 3:34 pm, Bill <[email protected]> wrote: > > > Builder Dave Moulton sheds some light on the subject in this 2006 blog > > entry: > > >http://davesbikeblog.squarespace.com/blog/2006/8/18/shimmy-re-visited... > > > On Dec 13, 7:59 pm, William <[email protected]> wrote: > > > > I weigh about 175. The whole bike rig with both bags on it as > > > described above is probably in the low 40s. So maybe 215 bike + cargo > > > + rider. Straight medium. :) > > > > My bars are 1-2 inches above saddle height. > > > > On Dec 13, 4:21 pm, Seth Vidal <[email protected]> wrote: > > > > > On Mon, Dec 13, 2010 at 7:13 PM, William <[email protected]> wrote: > > > > > The fundamental conclusion I can make already is that front end shimmy > > > > > at moderate speed no-handed is not a fundamental property of this > > > > > bicycle. It's a property of a particular configuration on this > > > > > bicycle. If I don't like it, I can configure this bike differently. > > > > > If I choose to configure my bike this way, I should be prepared to > > > > > accept some shimmy. Jan's article encouraged me to experiment, and > > > > > I've started doing that, and I'm learning more about my bike, and > > > > > that's all good stuff. > > > > > How much do you weigh + yourstuff? > > > > How Are the bars set up vis-a-vis the saddle? > > > > > -sv > > -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
