With some exceptions (like life-threatening high-speed wobs, no thanks)... maybe it's time we just embrace the shimmy... it could just be our bikes telling us:
Slow the F down... Put your damn hands back on the bars Get a trailer if you wanna haul sh** Turn off that awful music on your iPod, it's giving me the shimmies Get me some decent tires and a nice headset, you cheapskate Don't worry about it... It's what makes me ride so nicely at all other times.... I fully expect to discover a shimmy in my Bomba (at some point)... I'll try not to freak out... Happy Friday, everyone... I'm ready to shimmy myself... Peace, BB On Dec 10, 3:12 pm, William <tapebu...@gmail.com> wrote: > Mike > > This is part of the voodoo feel to the whole thing. You can find an > article that says knobbies damp out shimmy. You can find another that > says knobbies supply the excitation force for shimmy. You can find > another article that states that wide tires like knobbies are > typically more compliant and therefore enable low frequency > oscillations to be amplified by the system. > > My first few experiments are going to be: > > 1. Baseline the bike. Log initial condition of all independent > variables that I might change. Attempt to measure the frequency and > amplitude of the shimmy > 2. Vary front tire pressure and ride. Note changes > 3. Vary rear tire pressure and ride. Note changes > 4. take reference weight (like maybe two full water bottles) and put > them at various locations on the system and note any changes > A. On front rack > B. In H2O cages > C. In jersey pocket > D. On rear rack > E. maybe elsewhere > 5. Change tires > 6. Change front wheel > 7. Change rear wheel > 8. Tighten headset or similarly damp steering > 9. Load rear end heavily > 10. Load front end heavily > > On Dec 10, 11:44 am, Michael_S <mikeybi...@rocketmail.com> wrote: > > > > > Funny, Bill, that you say your Hillborne shimmied. The one I had (now > > sold) was the most stable bike I've ever ridden with no hands in my > > life. I could have had a 3 course dinner while riding and not even > > think about touching the bars. I had the standard Riv supplied Tange > > headset and even with Schwalbe Smart Sams ( a knobbie tire) it was > > smooth as glass. The replacement bike, a used Ram, is not as stable, > > but is more like other bikes I've had. Neither bike has any shimmy at > > all. I did own, for a while, a Cotic Roadrat , but that baby was > > shimmy city and was sold quickly. On that bike a headset change > > quieted it as did a tire switch. But I could not get rid of it. > > > I even think the size and shape of the rider could influence it > > dynamically as much as bike geometry and even things like tire tread > > pattern. > > As others have mentioned above, shimmy is a complex set of factors, > > and due to system (bike/rider) to system variation it can affect one > > of identical bikes and not the other. > > > ~Mike~ > > > On Dec 10, 11:18 am, William <tapebu...@gmail.com> wrote: > > > > Allan, thanks for that suggestion. > > > > On Dec 10, 11:10 am, Allan in Portland <allan_f...@aracnet.com> wrote: > > > > > BTW, there's the Bicycle Quarterly Reader's Review > > > > list,http://groups.google.com/group/bqrr, that was created as a venue > > > > for > > > > precisely these types of discussions. > > > > > Not saying you can't discuss the mag anywhere you please, just saying > > > > we'd really appreciate the discussion there. :-) > > > > > Carry on, > > > > -Allan- Hide quoted text - > > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
