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doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 8:12 am
by wdannhardt
Thanks for all the responses I got regarding the Doohicky fix.
I wonder why the spring fails? I can understand the stock doohicky
failures:
- cheap welded design
- soft material
- refusal to admit for liability reasons
But the spring is not "cycled", it is set at a static load. Once the
screw is tightened on the bracket, the spring never moves or changes
tension. What would cause it to fail? And a better question, why
would we expect the replacement spring to last any longer than the
stock? Is the replacement a different material, or shot-peened for
longer life?
I read all the posts of people having "peace of mind", but it seems to
me that it is misplaced.
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 9:10 am
by Doug Herr
On Wed, 18 Oct 2006, wdannhardt wrote:
> Thanks for all the responses I got regarding the Doohicky fix.
>
> I wonder why the spring fails? I can understand the stock doohicky
> failures:
>
> - cheap welded design
> - soft material
> - refusal to admit for liability reasons
>
> But the spring is not "cycled", it is set at a static load. Once the
> screw is tightened on the bracket, the spring never moves or changes
> tension.
If I remember right, the explanation has to do with the loose
fit of the stock doo. This causes the spring to basically
vibrate during operation.
> What would cause it to fail? And a better question, why
> would we expect the replacement spring to last any longer than the
> stock? Is the replacement a different material, or shot-peened for
> longer life?
Mike can fill in on how it is better, but it is indeed better.
Plus you have tighter fit for the new doo on the shaft, so there
is less vibration in operation.
--
Doug Herr
doug@...
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 9:32 am
by wannabsmooth1
--- In
DSN_KLR650@yahoogroups.com, "wdannhardt" wrote:
>
> Thanks for all the responses I got regarding the Doohicky fix.
>
> I wonder why the spring fails? I can understand the stock doohicky
> failures:
>
> - cheap welded design
> - soft material
> - refusal to admit for liability reasons
>
> But the spring is not "cycled", it is set at a static load. Once the
> screw is tightened on the bracket, the spring never moves or changes
> tension. What would cause it to fail? And a better question, why
> would we expect the replacement spring to last any longer than the
> stock? Is the replacement a different material, or shot-peened for
> longer life?
>
> I read all the posts of people having "peace of mind", but it seems to
> me that it is misplaced.
>
The aftermarket springs in my kits are indeed of a different material.
The stock springs have sometimes had fairly sharp corner where the
wire transitions from the body to the hook. The stock springs are also
too long after a few thousand miles, sometimes sooner.
Some of us have been to multiple tech days, and worked on enough bikes
to have a pretty good feel for what makes these things break. I quit
counting wrencing on more than 200 bikes.
The current model spring has been in place since 6 months into the
program. Only the very first batch (prototypes) had any breakage.
These prototypes were actually purchased before I bought the program
back, and started selling them under my own name. Jake had a few
springs break, as I helped replace them.
I realize nuance is smetimes difficult to capture on the internet. Why
would you say peace of mind is misplaced?
all the best,
Mike
Eagle Mfg & Eng since 1990
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 9:51 am
by Thor Lancelot Simon
On Wed, Oct 18, 2006 at 01:10:49PM -0000, wdannhardt wrote:
>
> But the spring is not "cycled", it is set at a static load.
Actually, it is cycled. There is some slop in both ends of the
connection. You can tighten up the doohickey end if you get a special
doohickey made for a press-fit, but you may not want to. The balancer
system used to have a cush drive at the other end to absorb the shock
at each end of its maximum travel, but the springs in that cush drive
tended to break, and in 1996 they removed it.
Devon Jarvis' original doohickey was made for a tight fit -- he had to
lightly file it to fit on the shaft in his bike. Eventually he decided
that in fact a looser fit might be a better idea. You can probably find
his message about this in the list archives.
Thor
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 9:54 am
by Moose
As I am a lover of things not breaking while I ride them, and learning how to fix my own stuff I would like to attend a wrench day. Even if it is just to watch and help others. Has there been one in the Durham, NC area lately or is there one coming up? Is there a way to find out how many people on the list are in the area? I would have to order the kit and have it ready in advance, but you get enough gearheads together and something will happen!
wannabsmooth1 wrote: --- In
DSN_KLR650@yahoogroups.com, "wdannhardt" wrote:
>
> Thanks for all the responses I got regarding the Doohicky fix.
>
> I wonder why the spring fails? I can understand the stock doohicky
> failures:
>
> - cheap welded design
> - soft material
> - refusal to admit for liability reasons
>
> But the spring is not "cycled", it is set at a static load. Once the
> screw is tightened on the bracket, the spring never moves or changes
> tension. What would cause it to fail? And a better question, why
> would we expect the replacement spring to last any longer than the
> stock? Is the replacement a different material, or shot-peened for
> longer life?
>
> I read all the posts of people having "peace of mind", but it seems to
> me that it is misplaced.
>
The aftermarket springs in my kits are indeed of a different material.
The stock springs have sometimes had fairly sharp corner where the
wire transitions from the body to the hook. The stock springs are also
too long after a few thousand miles, sometimes sooner.
Some of us have been to multiple tech days, and worked on enough bikes
to have a pretty good feel for what makes these things break. I quit
counting wrencing on more than 200 bikes.
The current model spring has been in place since 6 months into the
program. Only the very first batch (prototypes) had any breakage.
These prototypes were actually purchased before I bought the program
back, and started selling them under my own name. Jake had a few
springs break, as I helped replace them.
I realize nuance is smetimes difficult to capture on the internet. Why
would you say peace of mind is misplaced?
all the best,
Mike
Eagle Mfg & Eng since 1990
---------------------------------
All-new Yahoo! Mail - Fire up a more powerful email and get things done faster.
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doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 9:55 am
by Lars Lemberg
>But the spring is not "cycled", it is set at a static load. Once the
>screw is tightened on the bracket, the spring never moves or changes
>tension. What would cause it to fail?
In my opinion, vibration from the engine causes motion in the spring.
After a time, metal fatigue weakens the material and the spring breaks.
>And a better question, why
>would we expect the replacement spring to last any longer than the
>stock? Is the replacement a different material, or shot-peened for
>longer life?
I don't know if it is a different material, but it is a different
color material, which could indicate a different material. And it is
a different thickness wire. My original spring is .048 in. diameter
wire, and the Eagle Mike replacement is .054 in. wire.
>I read all the posts of people having "peace of mind", but it seems to
>me that it is misplaced.
We are all sheep at some points in our lives.
Lars
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 10:28 am
by kestrelfal
--- In
DSN_KLR650@yahoogroups.com, Doug Herr wrote:
>
> On Wed, 18 Oct 2006, wdannhardt wrote:
>
> > Thanks for all the responses I got regarding the Doohicky fix.
> >
> > I wonder why the spring fails? I can understand the stock doohicky
> > failures:
> >
> > - cheap welded design
> > - soft material
> > - refusal to admit for liability reasons
> >
> > But the spring is not "cycled", it is set at a static load. Once the
> > screw is tightened on the bracket, the spring never moves or changes
> > tension.
>
> If I remember right, the explanation has to do with the loose
> fit of the stock doo. This causes the spring to basically
> vibrate during operation.
>
> > What would cause it to fail? And a better question, why
> > would we expect the replacement spring to last any longer than the
> > stock? Is the replacement a different material, or shot-peened for
> > longer life?
>
> Mike can fill in on how it is better, but it is indeed better.
> Plus you have tighter fit for the new doo on the shaft, so there
> is less vibration in operation.
>
> --
> Doug Herr
> doug@...
>
A spring under tension can also vibrate. It would
be the spring designers job to ensure the spring is
thoroughly analyzed and tested for all the vibrations it
would be exposed to in service in the KLR's engine to
ensure it would not fail due to fatigue.
Fred
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 10:32 am
by wdannhardt
Thanks Mike,
Your advice and experience is really appreciated. I'm a mechanical
engineer, so it's in my nature to be cautious especially when we're
talking about my precious KLR.
I hate opening up the engine to fix this ridiculous problem, but
since Kawasaki has not listened to their customers and corrected it,
I have no choice. When I fix it, I want to be sure that it will not
break again. It sounds like you've got enough experience with it to
have "peace of mind", so that goes a long way to convincing me. From
what I've read, you stand behind the kit and go the extra mile to
satisfy your customers if only Kawasaki would have done that.
I guess all that remains is to order the parts. Where do I get them?
Thanks,
Walt
--- In
DSN_KLR650@yahoogroups.com, "Lars Lemberg"
wrote:
>
> >But the spring is not "cycled", it is set at a static load. Once
the
> >screw is tightened on the bracket, the spring never moves or
changes
> >tension. What would cause it to fail?
>
> In my opinion, vibration from the engine causes motion in the
spring.
> After a time, metal fatigue weakens the material and the spring
breaks.
>
> >And a better question, why
> >would we expect the replacement spring to last any longer than the
> >stock? Is the replacement a different material, or shot-peened for
> >longer life?
>
> I don't know if it is a different material, but it is a different
> color material, which could indicate a different material. And it is
> a different thickness wire. My original spring is .048 in. diameter
> wire, and the Eagle Mike replacement is .054 in. wire.
>
> >I read all the posts of people having "peace of mind", but it
seems to
> >me that it is misplaced.
>
> We are all sheep at some points in our lives.
>
> Lars
>
doohicky spring failure - think about it
Posted: Wed Oct 18, 2006 11:34 am
by Yan
http://www.bigcee.com/klr650faq.html#links
look up ArrowHead under OEM Dealers
--- In
DSN_KLR650@yahoogroups.com, "wdannhardt" wrote:
>
> Thanks Mike,
>
> Your advice and experience is really appreciated. I'm a mechanical
> engineer, so it's in my nature to be cautious especially when we're
> talking about my precious KLR.
>
> I hate opening up the engine to fix this ridiculous problem, but
> since Kawasaki has not listened to their customers and corrected it,
> I have no choice. When I fix it, I want to be sure that it will not
> break again. It sounds like you've got enough experience with it to
> have "peace of mind", so that goes a long way to convincing me. From
> what I've read, you stand behind the kit and go the extra mile to
> satisfy your customers if only Kawasaki would have done that.
>
> I guess all that remains is to order the parts. Where do I get them?
>
> Thanks,
> Walt
>
> --- In
DSN_KLR650@yahoogroups.com, "Lars Lemberg"
> wrote:
> >
> > >But the spring is not "cycled", it is set at a static load. Once
> the
> > >screw is tightened on the bracket, the spring never moves or
> changes
> > >tension. What would cause it to fail?
> >
> > In my opinion, vibration from the engine causes motion in the
> spring.
> > After a time, metal fatigue weakens the material and the spring
> breaks.
> >
> > >And a better question, why
> > >would we expect the replacement spring to last any longer than the
> > >stock? Is the replacement a different material, or shot-peened for
> > >longer life?
> >
> > I don't know if it is a different material, but it is a different
> > color material, which could indicate a different material. And it is
> > a different thickness wire. My original spring is .048 in. diameter
> > wire, and the Eagle Mike replacement is .054 in. wire.
> >
> > >I read all the posts of people having "peace of mind", but it
> seems to
> > >me that it is misplaced.
> >
> > We are all sheep at some points in our lives.
> >
> > Lars
> >
>
klr wheel bearings
Posted: Wed Oct 18, 2006 12:56 pm
by W.V. Doran
Is there a site with directions for removing and installing KLR wheel bearings?
TIA
WVDoran
Scottsdale, AZ
---------------------------------
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