Re: Harley Davidson Dyna ride height

You're right. So do pendulums and damping frame flex isn't the ONLY thing a
steering damper absorbes.

 

Course not!

Can't figure it out myself either. Probably the same self-flagellating
characteristic which causes me to continue living like a hamster on a
wheel in New York City.

But maybe it's a matter of pride too. Melikes the supersports and I am
compelled to spread the gospel according to Valentino.

 

I tried. I recalled how much fun I'd had as a kid, when we were able to pretend
that Ms Smith's front porch was a space ship and how all that had been taken
away by an older kid proving that it was merely an old front porch. So I do
understand how hard it is for you to accept that the 4-stroke stuperbike you
have let yourself believe handles like a real race bike in fact is little more
than a dolled up tourer, or that factory attempts to make it handle like a race
bike have made it treacherous. If you want to continue your fantasies simply
ignore my posts and instead listen to the 2-wheel NASCAR crowd.

 

You are right. It reduces the *effects* of frame flex. I never said it prevents
the flex. But one effect of frame flex is steering oscillation. So why are we
argueing?

The frame is connected to the ground thru a stiff swing arm at the rear but thru
a hinge (the steering head) at the front. When flexed it acts like any spring
and oscillates, or tries to. This oscillation tries to shake the fork assembly
via the 'hinge' encouraging it (and the bars) to flop back and forth - the
dreaded wobble! A damper across that "hinge" (between frame and fork) damps out
that oscillation just like your rear shocks damp your rear springs'
oscillations.

Again consider what happens when a front tire strikes a bump whilst heeled well
over, say 30-45 degrees. The bump tries to drive the tire/wheel straight up.
This 'pulse' of energy gets divided into two vectors depending on the lean
angle. One goes into the suspension where it is absorbed as it would be were the
bike vertical. The other tries to both throw the tire/wheel upward and if the
frame is completely rigid the tire momentarily looses contact and traction. If
other bumps follow the front end of the bike "chatters" out and down you go.

Enough springiness is built into a proper frame to mitigate this. The vertical
componant of the bump's force, amplified by the leverage of the forks, twists
the frame at the steering head whilst trying to hurl the tire off the ground.
The frame then rebounds like a spring pushing the tire back down and minimizing
the "chatter". However, like any spring it has stored this energy and must
dissipate it else the frame will continue to oscillate.

Because of the "hinge" these oscillations appear to the rider as oscillations of
the bars and, depending on the natural frequency of the front end assemble, may
even grow into a "tank slapper". If a bike has this tendency at the speeds it
is ridden we buy a "steering damper".

No, this does not say that hitting a bump while heeled over is the ONLY thing
that causes frame flex. A rutted road might have the same effect and having
more power than one's frame could handle was a common source of tank slappers
into the 80's.

 

Since you thoroughly believe all this try an experiment. Head down a nice
straight road at 40 or 50 MPH. Put your hands on the tank and stand on the
pegs. Now shift your weight quickly from peg to peg shaking the frame. Since
frame movement doesn't effect the forks you won't generate a wobble and fall on
your arse will you? Bwahaha! But no, please do not try this .....

 

354 pounds DRY according to advertisements which are always optimistic. Have
you actually weighed your bike? How about Greek's Kawasaki?

IIRC a TZ weighs some 170# wet. I'll stick to my statement.

 

A 600ujm doesn't weigh over 400lb. Have a look at the specs and then
come to terms with reality.

Utter bollocks. Have another look at the specs for the litre class and
you'll see they've changed dramatically in the last 5 years.

Bwahahaha. Get fucking real.

I don't think Kenny Roberts was World Champion in the 125, 250, 500
and MGP classes. In fact Rossi is the only person to hold have managed
that feat so how does Kenny Roberts manage to have won a greater
variety of races? You can even add Snr & Jr versions of KR together
and you won't beat Rossi's titles.

 

Bollocks. You're backtracking because you're wrong.

 

Sorry, I'm used to the bikes raced here that are not limited by artificial
rules. The last TZ I actually saw weighed on a scale was a TZ- 250D with an
aftermarket Brit aluminum frame and wheels. IIRC it weighed 170 wet - with fuel
ready to race. I must assume that it would be easy to make one even lighter
today.

In any event niggling over 24# does not change the point - a 600 is far too
heavy to handle like a TZ.

 

Because aluminium is more prone to stress fractures.

Why am I telling you when you already knew that? It's that thick ****
Vito who needs educating.

 

A lot of steering dampers aren't even attached to the frame so how the
**** they can damp anything bar the steering I don't know.

 

Hmmm ... that may enable them to turn comparable lap times despite the handling
disadvantage?

Your Kawasaki has all these things??

I do not owe you an education. If you wish to fantisize that your 600 handles
just like a real racer be my guest. I don't argue with NASCAR fans who think
their cars are just like the ones on the track, nor with Jesus freaks who think
the rapture is coming any day now. Like I said, I had similar illusions when I
was about 7 years old.

 

Personal attack is the last refuge of those living in fantasy land when faced
with irrefutable truth.

 

That too Robert. But a roadracer doesn't expect any such bumps.

 

You dopey ****.

Read the fucking sig. The 4-stroke *is* my tourer.

So not only are you delusional about your knowledge of physics, metallurgy
and motorcycles, you can't read, either........

 

Right, you said: "AFAIK the 750 Suzi was unique in that it had a
car-like pump injecting oil directly into the crank and thence to the
bearings just like a 4-stroke (the difference being it was 'total loss'
like the old bikes). I never, ever heard of one failing but that doesn't
say it never happened of course. Other 2-strokes, including Suzi's
smaller bikes simply injected oil into the inlet air stream an were
indeed less reliable. The context was that 2-strokes can be made as
reliable as 4-strokes."

And the oiling system was *not* similar to a four-stroke's either, you
mental defective.

From this, and your use of the phrase "the context" it is reasonable to
infer that you were crediting at least most of Suzuki's reliability to
its (you thought) unique oiling system.


This was simply incorrect. It was *not* unique. This has now been proven
to you, and I note that you studiously ignored the evidence, which makes
you look something of a plonker.

Your statement that there were only three touring bikes worth a light
has now been qualified to include Harleys, Gold Wings and further
qualified to include only machines sold in the US, and *further*
qualified to exclude Guzzis because they didn't have enough dealers for
you. And you ignored the reference to the Z1.

This also makes you look a plonker.

When you are *wrong* on usenet, it's best to fess up, and everyone moves
on. Instead, you've dug yourself a massive hole in front of a global
audience. Which is amusing to see.

Just one question - do you now accept your claim that the GT750's oiling
system was unique to be nonsense?

 

You know that, I know that, everyone knows that, except Ryvita[1] whose
ignorance is simply serving as group amusement.

[1] "He takes the biscuit"

 

Oh .... OK

 

My bike weighs around 400 lbs wet.

And it's got 160bhp.

 

In previous posts, Vito informed us that bu$h's illegal
and immoral terror attack on the people of Iraq wasn't
motivated by Iraq's vast oil reserves, and that the bu$h
regime hasn't tortured anyone.
For his sake, I hope he's just trolling...


-


http://www.physics.byu.edu/research/energy/htm7.html

Ever wonder who benefits from the 150 MILLION
U.S. taxpayer dollars spent each DAY in Iraq?
http://www.commondreams.org/views04/0223-08.htm
http://www.corpwatch.org/article.php?list=type&type=21

"They are waging a campaign of murder and destruction. And
there is no limit to the innocent lives they are willing to
take... men with blind hatred and armed with lethal weapons
who are capable of any atrocity... they respect no laws of
warfare or morality."
-bu$h describing his own illegal invasion of Iraq.
http://www.robert-fisk.com/iraqwarvictims_mar2003.htm