Q: Who “Needs” a Steering Damper?

[emry]

 

 

This little guy is the problem.

 

Hmmm. Nemo... I miss his nonsense, as good as Ratch's but I could stand to read it all.

[Guest ratchethack]

Being an ignorant Philistine. . .1 zillion words later and I still don't get it.

Dave, at some point you have to realize that there are some people who will simply never get it, accept that, and move on. . . just as I do.

 

But if you're sincerely interested in understanding this, and have never experienced instability (as in a tank slapper) it's generally pretty difficult to comprehend what you're up against. Without the experience, I suggest that you're a far better candidate for more unplanned incidents (potentially far less benign than the experience you've posted about) than otherwise, on the "been there, no need to go there again" principle. I've had several, all on off-road bikes, all off-road or dirt road, none ever with a steering damper installed.

 

Every motorcycle, with the possible exception of something like the "stupid bikes" aka OCC "theme" bikes that are truly dangerous for a long list of other reasons, can, and will have instability at the fork under certain conditions. I find Ed's standard impulse test an excellent way to get the feel for how each individual moto behaves when it's forced into a slightly unstable mode, and to test what degree of steering damping it takes to control it. The way to induce slight instability is to follow his directions. It's not difficult, it's not dangerous, and his procedure is self-explanatory. Yes, I speak from repeat experience.

 

I don't ask you to trust me on this, but I assure you that inducing a slight wobble starting with a slight whack on the bars at low speed and working your way up under controlled conditions is infinitely safer -- and a whole lot more intelligent -- than your experience as posted numerous times here of running down an unfamiliar road at 120 MPH and overshooting your visibility so badly that you unexpectedly left the road for 200 feet with no idea what to expect past the 200 foot mark. At relatively low speeds, a deliberately induced fork wobble has a 100% probability of quickly self-cancelling. At higher speeds, the probability of self-cancelling tapers off, and the probability of self-perpetuating picks up. It's different with every moto. Best get a feel for it (and for what steering damping can do to stop it) starting at low speeds and low amplitudes, per Ed's procedure.

 

I consider a steering damper mandatory, and have used one (as provided and intended by each mfgr.) on every road bike I've owned. The reasons are: 1. Enhanced accuracy and control and 2. Enhanced safety.

 

If you have problems with Ed's version of the old impulse test, or just don't like it, may I suggest find a procedure you like better, or a write-up of the same procedure that you like better. NOTE: I didn't write Ed's procedure, and he didn't dream it up himself, either. You might send Ed an email with your objections. He's pretty good about answering. His email address is published at GuzziTech, at the link I provided earlier.

 

Sure hope this helps.

[docc]

On another, related, note:

 

Why is 45 mph ( about 72 kph) the point at which motorcycles are most unstable (wobble prone)?

 

Seems like Kevin Cameron 'splained this once, but I don't recall; something about the harmonics of the front wheel size?

[Greg Field]

 

 

This little guy is the problem.

 

Hmmm. Nemo... I miss his nonsense, as good as Ratch's but I could stand to read it all.

 

You're right. Nemo was full of shit, but his writing style didn't make one's eyes bleed.

[Greg Field]

Being an ignorant Philistine, I need further Clarification from Ratchet Hack:

Question 1: I need a steering damper to ensure the level of safety acceptable to me. Safety from tank slappers, causes by the very occasional perfect storm of tire, road, velocity, weight balance, too little rake and trail, flexing frame, imperfect alignment, rider input, etc. Why Ratchet do you need a damper? 1 zillion words later and I still don't get it.

Question 2: I might have gotten it and fully agreed with you, but you suggested that it is perfectly fine to have damper set to minimum, take your hands off the bars and whack the bar. While the motorcycle has self centering engineered into the geometry, there clearly are factors that can produce lethal tank slappers, and whacking the bars strikes me being one of those factors.

If you have this much faith in whacking the bar while riding no handed with damper set to minimum, why would you suggest that dampers are needed?

 

 

I suspect Ratch does a lot of whacking . . .

[Greg Field]

On another, related, note:

 

Why is 45 mph ( about 72 kph) the point at which motorcycles are most unstable (wobble prone)?

 

Seems like Kevin Cameron 'splained this once, but I don't recall; something about the harmonics of the front wheel size?

 

So, the same speed for a 21-inch wheel as a 16? Do not believe everything he writes. I have edited him in the past. What he turns in as copy bears only the most general structural relationship to what you actually read in a magazine or book, or at least it did then . . .

[docc]

So, the same speed for a 21-inch wheel as a 16? Do not believe everything he writes. I have edited him in the past. What he turns in as copy bears only the most general structural relationship to what you actually read in a magazine or book, or at least it did then . . .

So, then. what is it?

 

Maybe the difference between my 17" Guzzi and the 18" Honda is 1.234 mph? It certainly seems that 40-45 mph is *touchy*, if you know what I mean, *touchy.*

 

More iterations of "gyroscopic progression?"

 

Or are we goin' back to N'Orlins on this?

[Greg Field]

Not sure. Mine isn't touchy anywhere. Maybe that's 'cause I do not know enough to set it up "properly" I wonder how much Ratchet would charge me to make mine unstable? Being a poor dumbass, I'm sure I could not afford it. Add in the price of a steering damper, and I'd have to sell my house, I'm sure.

 

Being too depressed by this to do otherwise, I think I'll just ride it, as I did today to work. No steering damper. and I didn't die. I'm the luckiest SOB yet born, I guess. Maybe if I did more whacking . . .? BFG: Are you listening?

[GuzziMoto]

Dave, at some point you have to realize that there are some people who will simply never get it, accept that, and move on. . . just as I do.

 

But if you're sincerely interested in understanding this, and have never experienced instability (as in a tank slapper) it's generally pretty difficult to comprehend what you're up against. Without the experience, I suggest that you're a far better candidate for an unplanned incident than otherwise. I've had several, all on off-road bikes, all off-road, none ever with a steering damper installed.

 

Every motorcycle, with the possible exception of something like the "stupid bikes" aka OCC "theme" bikes that are truly dangerous for a long list of other reasons, can, and will have instability at the fork under certain conditions. I find Ed's standard impulse test an excellent way to get the feel for how each individual moto behaves when it's forced into a slightly unstable mode, and to test the effects of steering damping. The way to induce slight instability is to follow his directions. It's not difficult, it's not dangerous, and his procedure is self-explanatory. Yes, I speak from repeat experience.

 

I don't ask you to trust me on this, but I assure you that inducing a slight wobble starting with a slight whack on the bars at low speed and working your way up under controlled conditions is infinitely safer -- and a whole lot more intelligent -- than your experience as posted numerous times here of running down an unfamiliar road at 120 MPH and overshooting your visibility so badly that you unexpectedly left the ground for 200 feet with no idea what to expect at the 201 foot mark. At relatively low speeds, a deliberately induced fork wobble has a 100% probability of quickly self-cancelling. At higher speeds, the probability of self-cancelling drops off, and the probability of self-perpetuating picks up. Best get a feel for it (and for what steering damping can to to stop it) starting at low speeds and low amplitudes, per Ed's procedure.

 

I consider it mandatory, and have used a steering damper on every road bike I've owned. The reasons are: 1. Enhanced accuracy and control and 2. Enhanced safety.

 

If you have problems with Ed's version of the old impulse test, or just don't like it, may I suggest find something you like better, or a write-up of the same procedure that you like better. NOTE: I didn't write Ed's procedure, and he didn't dream it up himself, either. You might send Ed an email with your complaints. He's pretty good about answering. His email address is published at GuzziTech, at the link I provided earlier.

 

Sure hope this helps.

 

Now I understand...

Hatchet Rack truly does not understand this subject, but is absolutely sure he's right.

It's amazing he has time to type all this B.S., where does he find the time with all the whacking he does?

[Guest ratchethack]

I figure it’s an optimum time to flush out the rest o’ the Luddites and dabblers in the occult and paranormal on this one – get ‘em all out in the open, so to speak, where they can expose the mindset that drives crash statistics far beyond where experience, knowlege, and the exercise of plain common sense would otherwise take the numbers. I expect some of the responses to this post will do just that.

 

My my. . . Not many surprises here yet -- but JUST LOOK at wot's been flushed out o' the bottom of the septic tank overnight! Why, the smell alone is powerful enough to peel paint. . .

 

Those with sincere interest in this topic (I suspect there are actually quite a few) will already have noted the ONLY outside sources of credible, professional expertise on the topic that have been brought to this thread from the start. They'll also have noticed what postions taken here are consistently supported by them, and who brought them.

 

The sincerely interested will also have noted that, dredged up and dragged in by the usual suspects, we have the baseless sturm und drang of the ignorant, with NO backup of any kind for the indefensible positions that have now been fully exposed here. Instead of arguing any of the professional expertise provided on its merit (or lack thereof), we have the usual childish regression to school-yard name-calling as a common, gutter-level substitute for intelligent discussion. . . (And these are adults?)

 

I reckon all the Luddites, practitioners of the paranormal, and Voodoo devotees, having now fully identified themselves (looks like the usual suspects dancing around to me) have worked themselves up into an emotional frenzy, and will now continue to perform increasingly wilder gyrations to the drumbeat of thudding idiocy, sacrificing anything that reminds them of the gaping absurdity of their own beliefs on the fire, and perhaps immolate themselves to further illustrate their "wisdom". . .

 

Primal stuff! Wotta spectacle! Somebody call National Geographic.

 

By all means, carry on!

 

 

The Extremely Twitchy Red Frame Demon

In another of his many deceitful forms.

When reality becomes too annoying for comfort,

You can always place your faith in demon worship

[docc]

Not sure. Mine isn't touchy anywhere. Maybe that's 'cause I do not know enough to set it up "properly" I wonder how much Ratchet would charge me to make mine unstable? Being a poor dumbass, I'm sure I could not afford it. Add in the price of a steering damper, and I'd have to sell my house, I'm sure.

 

Being too depressed by this to do otherwise, I think I'll just ride it, as I did today to work. No steering damper. and I didn't die. I'm the luckiest SOB yet born, I guess. Maybe if I did more whacking . . .? BFG: Are you listening?

 

I guess I should be clear saying that my Sport isn't touchy or twitchy either. Never has been (again, there was that high speed weave "as delivered").

 

I was talking more generally about motorcycles and the 45mph harmonic.

[Skeeve]

On another, related, note:

 

Why is 45 mph ( about 72 kph) the point at which motorcycles are most unstable (wobble prone)?

 

Seems like Kevin Cameron 'splained this once, but I don't recall; something about the harmonics of the front wheel size?

 

That was 35mph on my old GL1200 ratbike [wreck survivor, no more rear bags or case, front tire prone to cupping, who knows how "tweaked" everything was?]: no noticeable fluctuations or other nonsense w/ one hand on the bars, but remove hands and immediately the bars started waggling. If the throttle lock was on at that speed, I suspect it would have been a gradually increasing wobble; I was never tempted to find out after discovering this characteristic.

 

OTOH, I could set the throttle lock at 70 per and flap my arms like a bird w/ no ill f/x, much to the amusement of the riders or cagers behind me...

 

Ride on!

 

NB: the GL1200 had a 130/90 x 16" front wheel, for whatever that's worth.

[docc]

While fear may certainly trigger, or at least, contribute to, physical disorders, intellectual pursuit is known to create similar manifestations. I recall late nights studying pathology or neurophysiology when a frantic call would come from a fellow student, "I think I've got Chapter Four!" Regarded as "Medical Student Syndrome" , would-be mechanics can induce some of the same effects.

Indeed, not only have I probably given my Guzzi some of its electrical problems, but attempting to fettle the suspension (to better it, of course) actually impaired it and contributed to a crash.

But the VooDoo wasn't begun out of fear, merely intellectual pursuit.

"No coward soul is mine
No trembler in the world's storm-troubled sphere:
I see Heaven's glories shine,
And faith shines equal, arming me from fear." -Emily Bronte

[Guest ratchethack]

While fear may certainly trigger, or at least, contribute, to physical disorders, intellectual pursuit is known to create similar manifestations. I recall late nights studying pathology or neurophysiology when a frantic call would come from a fellow student, "I think I've got Chapter Four!" Regarded as "Medical Student Syndrome" , would-be mechanics can induce some of the same effects.

 

Indeed, not only have I probably given my Guzzi some of its electrical problems, but attempting to fettle the suspension (to better it, of course) actually impaired it and contributed to a crash.

 

But the VooDoo wasn't begun out of fear, merely intellectual pursuit.

 

"No coward soul is mine

No trembler in the world's storm-troubled sphere:

I see Heaven's glories shine,

And faith shines equal, arming me from fear." -Emily Bronte

Thanks for this, Docc.

 

Lately, I've begun to think my Guzzi is coming down with Munchausen Extremely Twitchy Syndrome by Steering Damper Proxy. . .

 

Emily Bronte certainly puts this in a different perspective than Ray Parker, Jr.: "I ain't afraid o' no ghost."

[docc]

Or, as I hear in the colloquial vernacular: "Lak ah sed, ah ain't skeered."