[RBW] Re: suggestions for shimmy?

2011-09-08 Thread NME
Ken: The rack is secure! It's not quite loose enough that I can unscrew the bolts by hand or that I can rattle it by shaking it. In any case, I'll be sure to keep an eye on it every couple of weeks and tweak as needed. Marc: Good idea with the cork fender washers. I'll invest in some the next

[RBW] Re: suggestions for shimmy?

2011-09-07 Thread NME
Thank you all for your really insightful comments! I tried a few more things, including some your suggestions -- made sure the wheels were aligned, checked tire pressure, etc. I noticed that the problem was much worse when I was on smooth asphalt, but would almost disappear when I was riding on

Re: [RBW] Re: suggestions for shimmy?

2011-09-07 Thread Ken Freeman
Congrats! I don't think its related to the self-restoring force. That is supposed to be generated in the tire/road contact patch. On Wed, Sep 7, 2011 at 6:33 AM, NME nicolemea...@gmail.com wrote: Thank you all for your really insightful comments! I tried a few more things, including some

RE: [RBW] Re: suggestions for shimmy?

2011-09-07 Thread Marc Schwartz
Dear Nicole tc Perhaps cork or leather fender washers (as sold by Velo Orange, Rene Herse (Boulder), and others) at the rack mounting bolts would provide sufficient damping to deal with the shimmy, yet allow enough tightening torque on the bolts to prevent them from working loose over time due

Re: [RBW] Re: suggestions for shimmy?

2011-09-07 Thread Ken Freeman
I like that idea, absorb some of the resonant energy present in the loaded rack, which is presumably vibrating. On Wed, Sep 7, 2011 at 12:29 PM, Marc Schwartz mschw...@nmsu.edu wrote: Dear Nicole tc Perhaps cork or leather fender washers (as sold by Velo Orange, Rene Herse (Boulder), and

[RBW] Re: suggestions for shimmy?

2011-09-06 Thread Kelly Sleeper
What I would do .. Right or wrong.. Shrug Air tires to static inflation for tests. Remove load and ride.. Test for free handed shimmy. If it shimmies does hand on top tube stop it? Does coating make a difference.. Coast a bit faster slower etc. Try the other direction .. Remember Wind

[RBW] Re: suggestions for shimmy?

2011-09-05 Thread Scotty
My bike developed a frustrating shimmy that turned out to be from spokes loosening up. Retentioned the rear wheel and the shimmy went away. I guess there are probably a hundred different things that can cause a shimmy. -- You received this message because you are subscribed to the Google

Re: [RBW] Re: suggestions for shimmy?

2011-09-05 Thread PATRICK MOORE
One of my Rivs shimmied mildly with narrow tires; replacing them with 31 mm Kojacks seems to have put a stop to it -- tho' when I replace the seat wedge with a small front rack bag, it may come back. As Scotty said, the causes are legion. On Mon, Sep 5, 2011 at 9:20 AM, Scotty

[RBW] Re: suggestions for shimmy?

2011-09-05 Thread dougP
Nicole: Check the rack struts where they attach the rack. I also have the Nitto big back rack have noticed those can loosen up. It's not much but can allow enough play in the rack for it to move around. My guess is a bike is more sensitive to weight on top of the rack than on the sides.