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Q: Who “Needs” a Steering Damper?


Guest ratchethack

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That's fine, as you said it is not a clear cut issue. Chopper guys usually (or at least used to) list both the rake of the steering stem (as rake) and the extra angle the clamps add.

In my opinion the problem with adding angle in the clamps is that while the forks are pointed straight ahead the extra angle is in line with the steering stem. But as you turn the forks that angle kicks the front wheel off to the side. It is no longer adding its angle to the steering stem rake entirely. The more you turn the forks the more of that angle goes off to the side instead of in line with the steering stem. This is not a big deal on choppers (they handle poorly to begin with) but on a sportbike anything more then a small bit causes wonkey steering geometry as the forks turn. This not only would kick the front wheel off to one side but would cause the trail to change as well. That is why it is used on choppers and drag bikes mainly. In fact, Kosman, who make them for drag bikes goes so far as to point out that it changes fork tube angle, not rake. But again, that is splitting hairs. The important part is that it is a crude wonkey patch that should have been done differently if at all. Guzzi engineering, gotta love it.

 

Choppers rake out, sportbikes rake in (fork axis). It is well established that trail, not rake affect bikes stability, but this has never really acounted for how the bike really handles when the fork angle has a differential + or -. At least some chopper manufactuers have figured out what make their bike go straight and not kill people. Racers who rake in are nomrally very tight lipped. No compedative advantge to the neighbors ya know.

 

In my opinion the problem with adding angle in the clamps is that while the forks are pointed straight ahead the extra angle is in line with the steering stem. But as you turn the forks that angle kicks the front wheel off to the side. It is no longer adding its angle to the steering stem rake entirely. The more you turn the forks the more of that angle goes off to the side instead of in line with the steering stem.

 

Raking (out) a steering stem can produce "flop" at low speeds but raking the clamps does not, conversely doing the opposite to a sport bike increases turn in (less angualrity of the camber angle that produces the turn) and stability from the extra trail. Either of the later sounds like a benefit to me.

 

But in Guzzi terms we are only talking 0.5 degrees. The trail advantage is much greater than anything else at that point.

 

In my opinion the problem with adding angle in the clamps is that while the forks are pointed straight ahead the extra angle is in line with the steering stem. But as you turn the forks that angle kicks the front wheel off to the side. It is no longer adding its angle to the steering stem rake entirely. The more you turn the forks the more of that angle goes off to the side instead of in line with the steering stem.

 

True, but is this positve or negative depending on speed, the results are not linear. Remember counter steering. The argument is not as cut and dry as the term "rake". Above slow speeds the steering rotation needed to turn a motorcycle is small.

 

Many of these angles (OEM) are still achieved through test riders, the physics are not concrete.

 

I hope all of this makes sense without to many gramatical errors, I have had a few tonight.

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GM: Sometimes the US VIN corresponds to frame number but more often to engine number, so I'm not sure how useful it is.

 

Sorry, but I meant under the upper clamp. Does it read "01493100" or "01493130" (both early) or "501452" (most late)?

 

Axle nut or not?

 

It may or not be under the VIN plate, or alongside it. US bikes are hard to decipher. You almost certainly have the early, non-canted triple clamps.

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emry, you clearly have a good grasp of this and I agree with a lot of what you're saying. We differ mainly in the details. But I still think that Guzzi's ill thought out first attempt at addressing any handling issues with the V11, real or not, by raking out the fork tube angle (even though it is only 1/2 a degree it is still going in the wrong direction) was a mistake. And whether they compensated for this change which reduced trail by adding more back in thru offset I don't know. But to assume they did is a mistake. And yes, as I have also said, trail is more a factor in stability then rake. That makes Guzzis choice to lessen the fork angle thru the triple clamps (raking the front end out) seem even stranger and less thought out.I find it interesting that every bit of info I can find on V11 steering geometry seems to give the same rake numbers and I think I have seen two different numbers for trail.

Greg, I am glad to know that we have one of the "good" ones.

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But I still think that Guzzi's ill thought out first attempt at addressing any handling issues with the V11, real or not, by raking out the fork tube angle (even though it is only 1/2 a degree it is still going in the wrong direction) was a mistake.

Sure seems like a mistake!

They should have decreased the rake (raked in) at the triples!!!!

 

Greg, I am glad to know that we have one of the "good" ones.

Maybe it was the tweaked triple clamp V11s that gave the red frame a bad rep?

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Sure seems like a mistake!

They should have decreased the rake (raked in) at the triples!!!!

 

 

Maybe it was the tweaked triple clamp V11s that gave the red frame a bad rep?

Not sure you understand what I meant, in case you didn't let me point out that as I understand it on later red frame bikes Guzzi used clamps that changed the rake from 24 degrees (or what ever it was) to 24.5 degrees to add stability and slow the steering down. That is what I meant by "raked out". Going the other way would not have been a good idea in my opinion and I think 24 (if that is what they have) degrees of rake on a Guzzi with the right amount of trail is just about right. For the type of bike it is it gives the right balance of speed and stability. I know some have said there are issues with them, especially the early ones, but I still don't think that is a geometry thing but perhaps something not right with the bikes. Maybe it was built poorly or the frame is not straight or to spec. What ever it is it does not effect my wifes V11.

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Guest ratchethack
Sure seems like a mistake!

They should have decreased the rake (raked in) at the triples!!!!

. . .

Maybe it was the tweaked triple clamp V11s that gave the red frame a bad rep?

Chronic confusion takes a truly formidable toll. . . :whistle: Don’t you see by now that it’s not rake, not trail, not triple clamps, not the frame, nor ignorance/neglect of chassis setup, nor ignorance/neglect of steering damper -- nor any conceivable combination thereof -- none of these things a-tall??

 

Why, by the simple process of elimination, it's obvious that the only thing we have to fear is demon possession itself:

 

A certain number of those things're extremely twitchy, no matter how they're set up. Many of these are no longer on the road 'cause they were totaled in crashes. Other specific bikes aren't twitchy, no matter how they're set up.

You see, sad but evidently true, ;) the important thing to understand here, as explained above^, is that the Guzzi owner (any Guzzi owner) is as helpless as a newborn babe against the likes o' the Extremely Twitchy Demon. :( Your Guzzi is either possessed, or it isn't. If it is, your only option to the inevitable crash and burn scenario is Voodoo demon exorcism, as explained previously.

 

Still not clear? You must be blocking. A few haikus and deep breathing will open up and clear blockage, allow chi to flow unrestricted:

 

HAIKU

 

Go soothingly on Short Frame Guzzi.

Fear and treachery hide in cold and lonely depth of darkened minds;

there lurks Extremely Twitchy Demon!

 

HAIKU

 

Some demon possessed, some not.

No chassis set-up, nor steering damper ever mask work of such evil;

Only Extremely Twitchy Demon himself reveal if your Guzzi in bad certain number!

 

HAIKU

 

Like mud elephant waving through the sea,

Extremely Twitchy Demon wreak havoc ten years now;

yet leave no tracks.

 

- Zen Master Hatchracket

 

post-1212-1253455981.jpg

 

Samurai Red Frame

Extremely Twitchy Demon

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Not sure you understand what I meant, in case you didn't let me point out that as I understand it on later red frame bikes Guzzi used clamps that changed the rake from 24 degrees (or what ever it was) to 24.5 degrees to add stability and slow the steering down. That is what I meant by "raked out". Going the other way would not have been a good idea in my opinion and I think 24 (if that is what they have) degrees of rake on a Guzzi with the right amount of trail is just about right. For the type of bike it is it gives the right balance of speed and stability. I know some have said there are issues with them, especially the early ones, but I still don't think that is a geometry thing but perhaps something not right with the bikes. Maybe it was built poorly or the frame is not straight or to spec. What ever it is it does not effect my wifes V11.

So you think that raking out at the triples which decreases trail is a good idea?

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Raking (out) a steering stem can produce "flop" at low speeds but raking the clamps does not, conversely doing the opposite to a sport bike increases turn in (less angualrity of the camber angle that produces the turn) and stability from the extra trail. Either of the later sounds like a benefit to me.

I am with Emry! Rake it in at the triples, not out, you silly chopper wannabes! (just kidding, not personally attacking, yet...)

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Chronic confusion takes a truly formidable toll. . . :whistle: Don’t you see by now that it’s not rake, not trail, not triple clamps, not the frame, nor ignorance/neglect of chassis setup, nor ignorance/neglect of steering damper -- nor any conceivable combination thereof -- none of these things a-tall??

So, you don't believe that decreased trail increases the need for a steering damper?

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All right . . . this is really challenging thinking ( and good ale) . . . (and I didn't get to ride 1000 miles in this tropical weather system, as planned), so, I've been reading and giving this a lot of (foggy) thought.

 

First, I think it's time a *couple* of forum members came to terms with "some iz an' some ain't." While there are numerous parameters and a myriad of adjustments and changes that can be effected to these bikes, this is , after all a mechanical device, however complex.

So, while the whole Demonic Vampirette thing has been fun, it's no longer productive. Let's get on with the fact that a thorough and productive set-up is critical.

(Don't let that deter you from linking hot images of Vampirettes; that last one reminded me of a "girl" I dated in college . . .)

 

Second, if increasing trail increases stability, why did my Sport get better by raising the rear ride height, fitting a smaller rear tire, and dropping the triple clamps (thereby decreasing trail?)

 

I would suggest it's about weighting the front, a trait for which Guzzis are not known.

 

"Damn the (trail), full speed ahead!"

 

(desperate to ride again, docc)

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Guest ratchethack
All right . . . this is really challenging thinking ( and good ale) . . . (and I didn't get to ride 1000 miles in this tropical weather system, as planned), so, I've been reading and giving this a lot of (foggy) thought.

 

First, I think it's time a *couple* of forum members came to terms with "some iz an' some ain't." While there are numerous parameters and a myriad of adjustments and changes that can be effected to these bikes, this is , after all a mechanical device, however complex.

So, while the whole Demonic Vampirette thing has been fun, it's no longer productive. Let's get on with the fact that a thorough and productive set-up is critical.

Docc, I always appreciate sincere interest^ unsullied by the "default level" closed-minded silly ego problems and the associated garden-variety personal agendas that so often seem to trump all logic, all objectivity, all understanding, and all common sense with some people, as we've seen in this thread and o-so-many others. . . Beyond childish, it's just so utterly tedious, and I agree -- life is way way too short. . . <_<

 

OTOH, repetition and a little visual imagery doesn't seem to hurt, and actually seems to occasionally be capable of penetrating even the thickest toxic mental sludge. Just my observation, but I b'lieve it's actually taken a toll on the status quo here lately. ;)

 

EXAMPLE: As illustrated so very many times hereabouts, I reckon the idea that "some iz an' some ain't" under demonic control of the UNEXPLAINED, the PARANORMAL, and the UNSUBSTANTIATED has been quite well exposed by now, despite the fact that this exposure will not likely EVER penetrate the shroud of darkness and denial confounding the minds of a few posters to this here thread. . .

 

. . . But waddayagonna do? :huh2:

 

But yes -- by all means -- leave us move forward already!

 

I know you're well familiar with all of this, Docc, but others may not be.

 

As you note above, stability of a motorcycle is highly complex, with literally dozens of interdependent factors at work. Lately, it occurs to me by most painful observation that the term INTERDEPENDENT will no doubt be beyond the grasp of the aforementioned Mental Sludgies, but I'm confident that yourself, along with most reading this won't have any trouble with it a-tall. ;)

 

Whenever making chassis adjustments, the suspension tuning Pro's whose practical setup guides I've consistently cited and linked on this Forum over the years may not all agree on every point, but they are all 100% in agreement that when chassis tuning for a specific desired result, whenever possible, it is NEVER good practice to make more than one change at a time (this gets back to the interdependent thing). Otherwise, you forfeit the ability to make otherwise accurate comparisons by obscuring and altering the basis for the new frame of reference, and in many cases, by so doing, you're for the most part shootin' in the dark.

 

EXAMPLE : Though it's possible to change trail "stand-alone", without changing anything else, it's usually prohibitively expensive and complex to do this, and seldom done except by OEM model change or by serious, dedicated track devotees. NOTE: Custom offset and non-parallel triple clamps have been a fairly common way to alter trail WITHOUT altering RAKE for at least half a century, as I well recall. Remember the Ceriani forks of the '60's? :oldgit:

 

By simply raising the fork stanchions in the triples (the most common way trail is altered on moto's), of course you are ALSO changing rake and weight distribution at the same time, as you point out - not to mention ride height and ground clearance. Sacrifices are made and compromises are balanced out according to desired result.

Second, if increasing trail increases stability, why did my Sport get better by raising the rear ride height, fitting a smaller rear tire, and dropping the triple clamps (thereby decreasing trail?)

O' course "getting better" can mean lots o' things, with interdependencies of the changes you cite too numerous to list. . .

 

I don't know how your Guzzi handled before (or during, or after) you made these changes, but having done all the above (and a whole bunch more) separately myself in the process of re-springing and setting up both ends to work together, and finding all of what you've done all to my liking on my own Sport, and recalling your posts from years back, I reckon you and I have likely wound up somewhere fairly close within the same range of overall setup. Sure worked nicely this weekend for Yours Truly. :race:

 

Oh - and (still) nary a hint yet of the Extremely Twitchy Twitch Bitch, and that's after flogging the Sport extensively at fairly agressive speeds for many years up to the limits of ground clearance over typically rough, ripply mountain roads. Matter of fact, the Twitch Bitch has yet to cast even the tiniest spell on my Guzzi. Must be the Voodoo protection I had Madame Gatore Grosse Bayou perform on it. Madame prefers Bajan Dark rum. Her going rate is a liter per performance. I reckon that's the whole "secret" of mastering the UNEXPLAINED and the UNSUBSTANTIATED, right there. ;):lol:

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