Subject: Re: high speed instability
Author: Greg Field
Date: May 31, 2002, 1:35 PM
Post ID: 1710354680
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My understanding is that the instability happened on only a few bikes
and Guzzi totally disbelieved it until one of their own people
thoroughly checked out one of the wobblers to confirm that all the
obvious things (steering head bearings, swingarm bearings, wheel
bearings, and so on) were OK and then was seriously injured in a crash
when he test-rode it.
Guzzi then took that bike and a few other wobblers back to Italy. A test
rider was killed on one. After that, Guzzi and Berliner would take any
bike back that was a wobbler and destroy its frame.
As far as I was able to learn, Guzzi attributed the problem to an
undetermined set of individual factors on a few individual bikes that,
when combined with the police windshield and rear weight loading,
resulted in wobbles.
If your bike doesn't wobble by 90 mph, it probably never will. Then
again, Roy Harvey's Ambo wobbled once and pitched him without (as far as
I know) showing any earlier symptoms of a wobble, so maybe we should all
worry, or at least watch loading and consider ditching our police
shields.
Greg Field
On Friday, May 31, 2002, at 12:58 PM, Zerhackermann wrote:
| I doubt that is the wheel that is wobbling. probably the tire getting a slight grab. Around here we have grated briudges, rain grooves, plastic glue on lines. all of them pull at a bike tire and make it feel like something is wrong. Never heard of an "infamous high speed wobble" on guzzis either...did I miss something? -----Original Message----- From: scott kelso [mailto:fores-@conknet.com] Sent: Friday, May 31, 2002 12:53 PM To: Loopfram-@topica.com Subject: high speed instability I would like to know if any list members have experienced the infamous high speed wobble on their loopframes and would be willing to share this experience with the group.My eldo is currently shod with Conti Blitz tires,and sports wixom bags,trunk and Bates 700 fairing.I have ridden the bike at an indicated 90mph with no hint of instability,although i can feel a little bobble in the rear tire when crossing over painted lines on the highway at high speed.Im wondering if the reported episodes of instability are a sudden event or are they caused by a dynamic set in motion by a rear wheel bobble such as i feel on my bike when passing slow moving vehicles on the highway.Would appreciate any info.Next weekend at Gunstock Ski resort there is a vintage bike show&swap meet on Sat.,vintage roadrace on Sun.,and an awesome hillclimb event on Wed.Check out www.gunstock.com for info.Hope to see more than than one loopeframe there this year.Will post pics in a couple weeks.Thanks Scott K. |
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My understanding is that the instability happened on only a few bikes
and Guzzi totally disbelieved it until one of their own people
thoroughly checked out one of the wobblers to confirm that all the
obvious things (steering head bearings, swingarm bearings, wheel
bearings, and so on) were OK and then was seriously injured in a crash
when he test-rode it.
Guzzi then took that bike and a few other wobblers back to Italy. A
test rider was killed on one. After that, Guzzi and Berliner would
take any bike back that was a wobbler and destroy its frame.
As far as I was able to learn, Guzzi attributed the problem to an
undetermined set of individual factors on a few individual bikes that,
when combined with the police windshield and rear weight loading,
resulted in wobbles.
If your bike doesn't wobble by 90 mph, it probably never will. Then
again, Roy Harvey's Ambo wobbled once and pitched him without (as far
as I know) showing any earlier symptoms of a wobble, so maybe we
should all worry, or at least watch loading and consider ditching our
police shields.
Greg Field
On Friday, May 31, 2002, at 12:58 PM, Zerhackermann wrote:
=
<excerpt><fontfamily><param>Courier</param><color><param>0000,0000,FFFF</p=
aram><smaller>I
doubt that is the wheel that is wobbling. probably the tire getting a
slight grab. Around here we have grated briudges, rain grooves,
plastic glue on lines. all of them pull at a bike tire and make it
feel like something is wrong.</smaller></color></fontfamily>
=A0
=
<fontfamily><param>Courier</param><color><param>0000,0000,FFFF</param><sma=
ller>Never
heard of an "infamous high speed wobble" on guzzis either...did I miss
something?</smaller></color></fontfamily>
=A0
<smaller>-----Original Message-----
<bold>From:</bold> scott kelso [mailto:fores-@conknet.com]
<bold>Sent:</bold> Friday, May 31, 2002 12:53 PM
<bold>To:</bold> Loopfram-@topica.com
<bold>Subject:</bold> high speed instability
I would like to know if any list members have experienced the infamous
high speed wobble on their loopframes and would be willing to share
this=A0experience with the group.My eldo is currently shod with Conti
Blitz tires,and sports wixom bags,trunk and Bates 700 fairing.I have
ridden the bike at an indicated 90mph with no hint of
instability,although i can feel a little bobble in the rear tire when
crossing over painted lines on the highway at high speed.Im wondering
if the reported episodes of instability are a sudden event or are they
caused by a dynamic set in motion by a rear wheel bobble such as i
feel on my bike when passing slow moving vehicles on the highway.Would
appreciate any info.Next weekend at Gunstock Ski resort there is a
vintage bike show&swap meet on Sat.,vintage roadrace on Sun.,and an
awesome hillclimb event on Wed.Check out
=
<underline><color><param>1999,1999,FFFF</param>www.gunstock.com</color></u=
nderline>
for info.Hope to see more than than one loopeframe there this
year.Will post pics in a couple weeks.Thanks Scott K.</smaller>
=
</excerpt>=
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