Topica Loopframe_Guzzi Archive
 

Subject: RE: high speed instability

Author: j s

Date: May 31, 2002, 3:07 PM

Post ID: 1710355155

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<P>Scott,</P>
<P>My eldo used to wobble at speeds of 90 mph or higher when it had the Bates fairing and bags. I relpaced the fairing with a National Cycle Police style windshield and the hard bags with leather and haven't (knock on wood) had a wobble since. I have never heard of any other loopframes besides an eldo occur with this phenomenon and only 1 out of 3 of my prevoiously owned eldos ever did this. My bike and I both are to old to challenge this any longer so I think that whatever the cause is, it can be rectified.</P>
<P>John S.<BR><BR></P></DIV>
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<DIV></DIV>>From: Zerhackermann <CHOPP-@HOTMAIL.COM>
<DIV></DIV>>Reply-To: Loopfram-@topica.com
<DIV></DIV>>To: Loopfram-@topica.com
<DIV></DIV>>Subject: RE: high speed instability
<DIV></DIV>>Date: Fri, 31 May 2002 13:56:54 -0700
<DIV></DIV>>
<DIV></DIV>>Okay I'll buy that. pay attention to loading, just like any other bike
<DIV></DIV>>
<DIV></DIV>>They had the same problems with the police K bike beemers. too much junk
<DIV></DIV>>in the trunk, big screen on the front...high speed ...front end gets
<DIV></DIV>>light...wham.
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<DIV></DIV>>
<DIV></DIV>>-----Original Message-----
<DIV></DIV>>From: Greg Field [mailto:seen-@mac.com]
<DIV></DIV>>Sent: Friday, May 31, 2002 1:37 PM
<DIV></DIV>>To: Loopfram-@topica.com
<DIV></DIV>>Subject: Re: high speed instability
<DIV></DIV>>
<DIV></DIV>>
<DIV></DIV>>My understanding is that the instability happened on only a few bikes
<DIV></DIV>>and Guzzi totally disbelieved it until one of their own people
<DIV></DIV>>thoroughly checked out one of the wobblers to confirm that all the
<DIV></DIV>>obvious things (steering head bearings, swingarm bearings, wheel
<DIV></DIV>>bearings, and so on) were OK and then was seriously injured in a crash
<DIV></DIV>>when he test-rode it.
<DIV></DIV>>
<DIV></DIV>>Guzzi then took that bike and a few other wobblers back to Italy. A test
<DIV></DIV>>rider was killed on one. After that, Guzzi and Berliner would take any
<DIV></DIV>>bike back that was a wobbler and destroy its frame.
<DIV></DIV>>
<DIV></DIV>>As far as I was able to learn, Guzzi attributed the problem to an
<DIV></DIV>>undetermined set of individual factors on a few individual bikes that,
<DIV></DIV>>when combined with the police windshield and rear weight loading,
<DIV></DIV>>resulted in wobbles.
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<DIV></DIV>>If your bike doesn't wobble by 90 mph, it probably never will. Then
<DIV></DIV>>again, Roy Harvey's Ambo wobbled once and pitched him without (as far as
<DIV></DIV>>I know) showing any earlier symptoms of a wobble, so maybe we should all
<DIV></DIV>>worry, or at least watch loading and consider ditching our police
<DIV></DIV>>shields.
<DIV></DIV>>
<DIV></DIV>>Greg Field
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<DIV></DIV>>On Friday, May 31, 2002, at 12:58 PM, Zerhackermann wrote:
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<DIV></DIV>>I doubt that is the wheel that is wobbling. probably the tire getting a
<DIV></DIV>>slight grab. Around here we have grated briudges, rain grooves, plastic
<DIV></DIV>>glue on lines. all of them pull at a bike tire and make it feel like
<DIV></DIV>>something is wrong.
<DIV></DIV>>
<DIV></DIV>>Never heard of an "infamous high speed wobble" on guzzis either...did I
<DIV></DIV>>miss something?
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<DIV></DIV>>
<DIV></DIV>>-----Original Message-----
<DIV></DIV>>From: scott kelso [mailto:fores-@conknet.com]
<DIV></DIV>>Sent: Friday, May 31, 2002 12:53 PM
<DIV></DIV>>To: Loopfram-@topica.com
<DIV></DIV>>Subject: high speed instability
<DIV></DIV>>
<DIV></DIV>>I would like to know if any list members have experienced the infamous
<DIV></DIV>>high speed wobble on their loopframes and would be willing to share this
<DIV></DIV>>experience with the group.My eldo is currently shod with Conti Blitz
<DIV></DIV>>tires,and sports wixom bags,trunk and Bates 700 fairing.I have ridden
<DIV></DIV>>the bike at an indicated 90mph with no hint of instability,although i
<DIV></DIV>>can feel a little bobble in the rear tire when crossing over painted
<DIV></DIV>>lines on the highway at high speed.Im wondering if the reported episodes
<DIV></DIV>>of instability are a sudden event or are they caused by a dynamic set in
<DIV></DIV>>motion by a rear wheel bobble such as i feel on my bike when passing
<DIV></DIV>>slow moving vehicles on the highway.Would appreciate any info.Next
<DIV></DIV>>weekend at Gunstock Ski resort there is a vintage bike show&swap meet on
<DIV></DIV>>Sat.,vintage roadrace on Sun.,and an awesome hillclimb event on
<DIV></DIV>>Wed.Check out www.gunstock.com for info.Hope to see more than than one
<DIV></DIV>>loopeframe there this year.Will post pics in a couple weeks.Thanks Scott
<DIV></DIV>>K.
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<DIV></DIV></div><br clear=all><hr>Chat with friends online, try MSN Messenger: <a href='http://g.msn.com/1HM305401/43'>Click Here</a><br>

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