steering dampers, need or not?
Coleman E. Howard
poster had mentioned that they had arms like popeye, and didn't need a
steering damper. .I replied that a steering damper is a real important
"safety" mod to any sportbike. In fact, I crashed way back in the 70s,
because I didn't have a steering damper.
I also stated that the omission of a steering damper causes a lot of
tank-slappers that could be avoided..
I got this reply..
-----------------
well....As much as I hate to argue with my elders..........
Stock geometry on an most sportbikes doesn't really lend itself to slappers
without having a real tight fisted rider.
Sure, there are times where you'll get some wobble. Hell, there are 2
sections of Blackhawk where I get headshake WITH a damper. However, there's
much that can be done without a damper...
The main cause for a tank slapper is a person trying physically to prevent a
tank slapper. You know how they start... The front tire is light, just
grazing the ground and is a bit crooked. It bites, throws the tire to the
other side, bites, throws back, on and on.
9 times out of 10, your bike can and WILL absorb this ITSELF. However, you
have to recondition your mental state to allow this. Your $1700 forks (bone
stock) will absorb this and straighten it out. However, if you're hanging on
trying to prevent it or saying "OH.....SHIT, I'VE GOTTA HANG ON OR I'LL FLY
OFF", you're going to make it worse. Let me repeat this. If you hang on
tight or try to stop it, you WILL MAKE IT WORSE.
What happens is that as you hang on, the force from the front tire moving
back/forth travels through your body and you transfer this motion through
the rest of the bike.
Watch this:
http://www.kens.com/slappercrash.mpg
You will see this exact thing happen. If he'd have had a loose grip, or
would have totally let go of the bars, I'd bet a LARGE chunk of change that
he would have recovered. But NO, Mr. Muscle man or Mr "OHMYGOD", had to try
to stop it. Bad move...
So, how do you maintain a loose grip? I flap my elbows anytime I think I'm
hanging on too tight. If you move your elbows up/down, your forearms are
forced to loosen up, and thus your grip will too. You have to just have a
constant mental awareness over it.
Another problem area that I've had in inducing headshake is coming out of a
corner and getting back on the bike. I'm hard on the throttle and will tend
to pull myself up with the bars and it will induce shake EVERY time. Again,
retrain mind to use legs, NOT arms to move around on the bike.
Now, all of that said, I have a damper on my bike, and it's the best one out
there. Why? Because there are time when doing all of the above still will
not prevent headshake.
I'm sure there are those of you out there who will argue, and say that
dampers are needed on every bike, etc, etc, etc. You're often the same guys
who think that crankming down on preload makes your springs stiffer. grrr.
But that's another diatribe, for another time.
-----------
comments anyone?
ceh
2001 GSX R1000
62 & don't know jack)
Larry xlax Lovisone
> comments anyone?
On the street... steering dampers are a band aid to the root cause of
poor geometry and lack of suspension tuning... they tend to wear out
more than aid the rider...
On the track... they are necessary evil for a rider to keep giving it
all the berries...
Larry L
94 RC45 #2
Lean & Mean it... it's the extended warranty in every corner of your
life...
Have a wheelie NICE day...
If it wasn't for us the fast lane would rust...
V4'S are music to the seat of my pants...
http://members.ebay.com/aboutme/-xlax-/
Saddlebag
>On the track... they are necessary evil for a rider to keep giving it
>all the berries...
>
> Larry L
And for the street too. From a recent MO review:
When Kawasaki decided to build an all-out track/racey ZX 6R, they weren't
kidding. I don't think the Kawasaki finishes last as a street bike, but it's
close and thank goodness the Ducati's here to save it. (Then there's the fact
that Cycle World, who hardly ever says anything nasty about any motorcycle,
reports getting into a nasty tankslapper on the street on the ZX-6R, Cycle News
reports the same thing happening to them on the freeway on their 6R, and our
swellheaded friend Sean had it happen to him on our bike too, and was very
nearly spat off. If you get one of these bikes, get a steering damper at the
same time.)
Bubba
<""netters2\"@com(spamblock)cast.net> wrote:
>On the street... steering dampers are a band aid to the root cause of
>poor geometry and lack of suspension tuning... they tend to wear out
>more than aid the rider...
Or, possibly more importantly, they can be a band aid for the poorly
maintained streets around here. I nearly broke my left thumb on my
EX500 when a pothole grabbed the front wheel and cranked the forks
hard left. Fortunately I was dragging my toes while inching through
rush hour traffic.
Steve
95 Buell S2
96 Kawasaki ZX7R
Kaybearjr
>Steering dampers? How important are they on a sportbike? In another area, a
poster had mentioned that they had arms like popeye, and didn't need a steering
damper. .I replied that a steering damper is a real important "safety" mod to
any sportbike. In fact, I crashed way back in the 70s, because I didn't have a
steering damper.
The last steering damper equipped bikes that I owned had the old-fashioned
friction discs underneath the steering head. That was back during the 1960's...
I need somebody to show me a steering damper that works well in *both*
vibrational modes.
That essay that you quoted referred to one of *two vibrational modes*
associated with the front forks, "speed wobble", which occurs as described,
when the weight on the contact patch is insufficient to cause the front tire to
align with the rear tire.
During a speed wobble, the forks themselves oscillate rapidly around the
steering axis at such a rapid frequency the rider can do nothing to prevent it,
no matter how strong he is. It's *over* before the rider can react, it has
either stopped, or the bike has spit the rider off. A light-acting steering
damper will hydraulically damp those oscillations, though...
The other vibrational mode is called "speed weave". Up to a certain point,
speed weave will automatically damp itself out, that's part of the dynamic
stability engineered into the chassis.
But, every motorcycle has a critical speed, above which it will go into a
divergent speed weave which the front tire cannot damp out. The steering head
itself is moving around in all three axes, and the frequency of this
oscillation is much lower than the speed wobble frequency.
A steering damper might help to raise the critical speed at which speed weave
begins, while making the steering feel heavier, since it has to be most
effective at lower stroking speeds than a damper set to reduce speed wobble.
But, I haven't looked into steering damping construction to see if any of them
utilize velocity-sensitive components like cartridge forks, or if they are all
just fixed orifice designs, which produce four times the damping force which
the stroking speed is doubled...
Saddlebag
>But, I haven't looked into steering damping construction to see if any of
>them
>utilize velocity-sensitive components like cartridge forks, or if they are
>all
>just fixed orifice designs, which produce four times the damping force which
>the stroking speed is doubled...
See: http://www.scottsonline.com/indexframe.html#scotts2.htm
_Bob Nixon_
<cehowar...@aol.com> wrote:
>Steering dampers? How important are they on a sportbike? In another area, a
>poster had mentioned that they had arms like popeye, and didn't need a
>steering damper. .I replied that a steering damper is a real important
>"safety" mod to any sportbike. In fact, I crashed way back in the 70s,
>because I didn't have a steering damper.
I've had a bunch of nasty "moderate-never lock to lock" tank slappers on
the following old & later new bikes under both sweepers and straight
line-(flexiframes & tire mismatch).
1975 KZ900: above 80 they would wobble in sweepers, thus forcing rider
to back off or avoid sweepers above 80MPH.
1977 KZ650: Same thing only ~100MPH sweepers.
1978 Suzuki GS1000: Fine in sweepers and straight line but some tire
combinations would induce violent straight line wobble; Lower frequency,
near lock to lock, tank slappers.
73, 75 RD-350 & 78 RD400s: Twitchy nervous little bikes, with 53" WB.
Got the back loose in some crap and had a minor tank slapper. I think
that most folks got into trouble, with RD's, because they'd power
wheelie in the 1st three gears.
00 SV-650 Accelerating while passing a slow cage in traffic and
unintentionally wheelied and turning at the same time, when the front
came down misaligned with rear, a moderate but disconcerting tank
slapper was the result. This happened a second time, during an
intentional but sloppy wheelie.
The GS nearly killed me several times around 79, until we found the
right post OEM tire setup; Perreli Phantoms. Once on the old, two lane,
Dumbarton Bridge at ~120MPH the bike started wobbling using both lanes.
Luckily there was no oncoming traffic at the time or I'd be pushing
daisies now. As a result of my experiences with those old bikes, I now
know how to deal with moderate tank slappers and their lesser cousins
"head shake".
Always lightly weighted bars, and gradually reduce power and don't grab
the brake.
On modern bikes, I've experienced light-moderate "head shake". The
Sprint, on the track accelerating off a bumpy turn and at 140+ in
variable cross wind conditions that made me ease off the throttle. On
one track day, I was also playing with "spinning up the rear", exiting
turns. The result was: on slower smooth surfaced exits, no problem but
on faster bumpy exits, two times I slid the back soo much I had moderate
but controllable, tank slappers.
Later on a rented R6 during TD, second gear bumpy turn exit, front
light, mild-almost fun "head shake".
The tank slappers we see on TV, from Moto GP to AMA races, are usually
caused by light front under hard acceleration, over rough road surfaces
to: rear to front traction based misalignment of the front and rear
wheel, under either hard acceleration and once in awhile under hard
deceleration, again wheel misalignment the culprit.
Steering Dampers are as others have already stated, a double edged
sword.
Rationale:
When a 530lb sport tourer has faster turn-in than a race replica, some
with steering dampers, some without, it's obvious that bike manufactures
have make compromises, in "race-rep" steering geometry, to favor
straight line stability over flickability, especially in tight turns. As
Larry X stated, on the street, steering dampers mostly just wear out
their riders but are a necessity at, balls-out, track pace. Scotts are
likely the best compromise as you can adjust the amount of damping, on
the fly, or turn off the setting that effects low speed (tight turns)
resistance. Also, others have suggested poorly set-up suspensions as a
contributor and I suppose this is possibly, if one is that out of touch
with what's going on under the seat.
Finally, too much throttle on exits with your R1 or GSXR1000 & don't
expect a steering damper to save your butt from a high side or post
wheelie errant touch down -:)
01 Sprint ST "RED"
Bob Nixon, Phoenix Az.
Coleman E. Howard
"Larry xlax Lovisone" <""netters2\"@com(spamblock)cast.net> wrote in message
news:YLycnTozufw...@comcast.com...
Larry, you are basically saying that the poster was correct. Dampers are
not needed for the street
I learn something new everyday...:)
ceh
2001 GSX R1000
Coleman E. Howard
"_Bob Nixon_" <bi...@nospam.nospam.com> wrote in message
news:F=zHPrRh4=b4RqHmnpMRHT=26...@4ax.com...
(snipped for space)
> Finally, too much throttle on exits with your R1 or GSXR1000 & don't
> expect a steering damper to save your butt from a high side or post
> wheelie errant touch down -:)
>
>
> 01 Sprint ST "RED"
> Bob Nixon, Phoenix Az.
Bob, after stating all those facts, tell me this. If you were to buy a brand
new 03 Daytona 955, would you get a steering damper for it? That is, if it
didn't come with one standard???
???
ceh
2001 GSX R1000
_Bob Nixon_
No. The Daytona's got a pretty slow (reads HS stable ) steering
geometry.
If you buy the MilleR, I doubt you won't need one either.
Coleman E. Howard
> >
>
> No. The Daytona's got a pretty slow (reads HS stable ) steering
> geometry.
>
> If you buy the MilleR, I doubt you won't need one either.
>
>
> 01 Sprint ST "RED"
> Bob Nixon, Phoenix Az.
The Mille R, comes standard with a Ohlins steering damper.. I wonder why?
:)
ceh
2001 GSX R1000
2002 Aprilia Mille R(soon)
(62 & don't know jack)
_Bob Nixon_
<cehowar...@aol.com> wrote:
>
>"_Bob Nixon_" <bi...@nospam.nospam.com> wrote in message
>news:LizIPqwqycdgItxi+jL+REhH=x...@4ax.com...
>> >
>>
>> No. The Daytona's got a pretty slow (reads HS stable ) steering
>> geometry.
>>
>> If you buy the MilleR, I doubt you won't need one either.
>>
>>
>> 01 Sprint ST "RED"
>> Bob Nixon, Phoenix Az.
>
>The Mille R, comes standard with a Ohlins steering damper.. I wonder why?
That's news to me. I actually rode an 01R and never saw the steering
damper.
Coleman E. Howard
> >
> >The Mille R, comes standard with a Ohlins steering damper.. I wonder why?
>
> That's news to me. I actually rode an 01R and never saw the steering
> damper.
>
>
> 01 Sprint ST "RED"
> Bob Nixon, Phoenix Az.
They are not top-mounted. They are mounted the same way they are mounted on
the gixxers..
On the Mille R models, 01 & 02, they come with Ohlin forks, shock, steering
damper, all standard..
_Bob Nixon_
<cehowar...@aol.com> wrote:
[...]
>They are not top-mounted. They are mounted the same way they are mounted on
>the gixxers..
>On the Mille R models, 01 & 02, they come with Ohlin forks, shock, steering
>damper, all standard..
I knew about the Ohlins suspension; front & rear, Brembo brakes and
lighter wheels but not the steering damper.
Larry xlax Lovisone
> Or, possibly more importantly, they can be a band aid for the poorly
> maintained streets around here.
What keeps you in the land of pointy boots and pot holes???
Bubba
<""netters2\"@com(spamblock)cast.net> wrote:
>
>
>
>> Or, possibly more importantly, they can be a band aid for the poorly
>> maintained streets around here.
>
>What keeps you in the land of pointy boots and pot holes???
Wife, family, job, friends, etc. My whole life is here. If I could
uproot all of it I'd get the HELL out ASAP. Just not practical,
though.