speed-sensitive steering damping

Is Hyperpro speed sensitive steering damping a good concept???

 

how about the electronic honda one

 

Id guess that it is a real good idea....it would go tight at higher speeds
yet relax around town at lower speeds.

Phil Scott

 

I want to know how it works ... ???

Cam
'00 ZX6R

 

Sensor in the seat?

Moike

 

sphincter sensor?

Cam
'00 ZX6R

 

Someone let Moike at loose on an internet connection
and the result was:

me too...to be truly 'road speed sensetive' u'd think it'd be hooked to the
pulse generator for the speedo and have a servo to wind it up and down with
speed...then it'd have to be calibrated an stuff...no mention of such a
thing...praps velocity sensetive with a bit of mechanical valving trickery?
anyway, wassamatter doncha got arms?

 

By "Speed sensitive" I am assuming you mean the speed the bars are being
flicked from side to side and not the speed of the bike itself?

Yes good idea (the 1st one that is) - low resistance for normal riding then
if you hit a bump and the bars try to twist out of your hands the damper
reacts to sudden changes and stops it from happening (or at least lessening
it).

Greg

 

It not road speed sensitive but handlebar rotation speed sensitive!!! When
the handle bar are turned slowly the damping is very low but the faster you
turn it, the more damping you have.

 

Why should the road speed of the bike have anything at all to
do with the valving of the damper?

All you should concern yourself with is frequency and amplitude
of front end oscillations.

 

On Mon, 13 Oct 2003 08:31:31 GMT, Timberwoof

[...]

Phil, your old dirt bike knowledge is getting in the way on this one.

Your arms and body tend to magnify any input towards oscillations in
spite of attempts to do the opposite, where' as a steering damper is
like a shock absorber, (think low Q resistive tank circuit) thus
causing oscillations to die out quickly.

So no, a light input on the bars at all speeds except when
deliberately counter steering. Properly designed motorcycles WANT to
go in a straight line, so if the rear end slides, it wants to right
itself via wiggle at the steering head. Our body mass just gets in the
way in such instances, so a passive approach is the best course.

The exception is light DIRT bikes on SOFT DIRT surfaces where you CAN
muscle the bike around with longhorn bars and even leveraging with leg
input. At low speeds on street bikes, a foot can help control a slide
on sand or gravel. Also, a well placed knee bounce can save SOME front
end tucks at the race track but generally only works for the Rossi set


Also, body steering on heavy street bikes is at best a secondary force
in comparison to counter steering and hanging off is moving the center
of mass to the inside, allowing the bike to lean less for a given
radius/speed. On dirt bikes, particularly at low speeds, body steering
to the outside is the norm or similar to low speed "non counter
steering" (steering head actually turning) on a pavement bike.

The same can be said, of steering the rear of a motorcycle via rear
brake or compression braking. It's more suited for light bikes on soft
surfaces but can be done on asphalt bikes to a lesser degree. Front
trail braking is less natural but effective, trading cornering
traction for braking. It's a vector sum, so the more the lean the less
braking and so on. This also tends to make the bike stand up and
requires additional counter steering to hold a line.

IMO, road conditions or lack of certainty of said, will dictate the
use of front or rear braking in a turn. (soft surface: rear brake,
hard surface: front brake or even both). The safe thing to do for
street riders is to get the braking out of the way prior to entering a
turn. The no brakes drill using compression to slow to bike, but
'generally' this requires good road memory, particularly on foliage
obscured, poorly marked roads. IMO, aggressive or late braking to
trail front braking is in the realm of the expert track rider. This is
different than just overcooking a turn, standing the bike up and
getting on the front binders, thus chancing going into the oncoming
lane. It's sometimes unavoidable, should be done in steps (straighten,
lean. straighten lean) and generally folks who find themselves in such
a predicament, could have just leaned in harder or "dare I say it",
slide the back out a bit (rear brake) momentarily, to correct the
apex.

More than the scope of this thread but I got carried away -


Bob Nixon
Phoenix AZ
01 Sprint ST "RED"
03 Suzuki ST "SILVER"

 

errr... I said the STEERING DAMPER goes tight at higher speeds with that
device..NOT your grip.

gripping tighter at higher speeds is a whole other range of issues...in a
speed wobble muscle tension and its delayed reaction can make a speed wobble
worse. and also make your arms tired. The steering damper has no such
delay or resonance.


Phil Scott

 

So...Bob... do you thing the progressive steering damper gets tighter or
loose with added speed?

My guess is tighter.

Phil Scott

 

It would have to have an input in digital form from the speedometer..that
would operate a restrictor valve in the hydraulic circuit of the steering
damper though a pressure electric transducer most likely.

Phil Scott

 

And how does the damper knows you're at 40mph coming out of a tight corner
and whip it onto the next straight? because then you might get some
headshake.
I wonder...

--Manu

 

No.

Too tight prevents a wobble to the extent that it causes a weave.

Too loose may not contribute to a wobble, but it does nothing to
damp a wobble.

 

Not really any news. Øhlins have had high speed adjustment on their off road
rotary steering dampers for years. BTW it look quite similar to the new
fancy Honda s.d.

/MBE

 

not likely at all...but worn and too tight bearings could...as the head
tended to click into ball indents off line then back out... thats stretching
it though.

Phil Scott

 

that move is still very very slow compared to a speed wobble.

Phil Scott

 

I agree, Phil.



Bob Nixon
Phoenix AZ
01 Sprint ST "RED"
03 Suzuki ST "SILVER"