V11 Suspension.......Or is it Geometry

[Greg Field]

I already know nothing will convince Ratchethack, but in case there are others here who find it more plusible that Aprilia spent all that money to change the frame because, allegedly, some journo called it twitchy than because there was an actual problem that exposed them to financial liability, see Nolan Woodbury's post in this link:

 

http://wildguzzi.com/forum/index.php?topic=28534.0

 

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. If you have a twitchy one, be wise and maintain and use your steering damper. And be careful.

[raz]

So where is a 1100 Sporti (pre V11) placed in a similar comparison? Wheel base? Rake? Length of stuff?

 

I'm not a very fast rider but I really liked the effect of raising the forks 10 mm up the triple trees and then I really noticed it being cancelled when I went from 70 profile rear to 60. I'm usually not the kind of guy that would immediately notice such things. I'm now considering raising forks 10 mm more, but there is a ground clearance issue of course, that should be considered at least.

[Guest ratchethack]

I already know nothing will convince Ratchethack, but in case there are others here who find it more plusible that Aprilia spent all that money to change the frame because, allegedly, some journo called it twitchy than because there was an actual problem that exposed them to financial liability, see Nolan Woodbury's post in this link:

 

http://wildguzzi.com/forum/index.php?topic=28534.0

 

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. If you have a twitchy one, be wise and maintain and use your steering damper. And be careful.

I have no problem with Nolan's comments wotsoever:

". . .The things I learned from Eraldo when he built the V11S/Ferracci project bike taught me some amazing things can be done with that engine. With an honest 100-hp at the back wheel, the bike's handling issues were really exposed. It wobbled in high speed corners. We tried a different shock, dropped the nose, steering dampener, tires....

 

During one track day a guy from Derbi scooters tried the bike and rode it through the wobbles. He ground the sidestand support away. When I asked him if the bike was scary he just shrugged, "It felt OK to me". "

With something near 100 rwhp on tap, and pushed to its limits, with the requisite race tires to prevent undue wheelspin out of corners (with their greater than OE F/R offset) and no extensive gussetting of the chassis to handle the additional 25% bump in torque and power curves, I'd expect the spine chassis to do all kinds of funny stuff winding up at the torque peak -- including wobbling due to chassis flex -- something on the order of the proverbial Flexi-Flyer.

 

But lack of chassis torsional rigidity to match a specifically race-prepped power delivery has ZERO to do with geometry (as in the title of this thread), it's not something that I believe would ever manifest itself in 99.9999999999% of the OE short frame Sports or RMs ridden on the road (mine included) -- Nor (getting back to the subject) does this have anything whatsoever to do with the OE Guzzi Sport's 25 degree rake and/or the fact that its wheelbase is 16 mm shorter than the V11 LMs.

A certain number of those things're extremely twitchy, no matter how they're set up.

I seriously doubt there's any legitimate evidence of this in anything close to OE state of tune.

 

But I'd be willing to consider the best you or anyone else has got. If this^ is it, it ain't squat.

[Greg Field]

Now you're saying the bike has to be stock to meet your criteria, whereas before the criteria was that they had to've been "set up"? Hmmm . . . I gotta believe no matter what is said, you'll toggle back and forth to maintain your belief. So be it.

 

People keep saying the same as you about the other Guzzis that wobbled and then were fixed. "Mine doesn't wobble!" Well, OK, maybe yours doesn't, and maybe you don't ride it very hard or haven't hit just the right bump yet while heeled over. People were seriously injured and even killed on the Eldos and LeMans 1000s, the former of which was scrapped and the latter of which was fixed in the second series and by recall of the first series after the fact with new parts.

 

I do not know of anyone killed on a V11 because of wobble, but I bet if I investigated with the engineers about why the change was made, I'd find that there are crashes behind it. I'll get to that when I have time to update "Big Twins," hopefully soon. I can tell you that that's why the earlier bikes were fixed, not because some journalista said they were twitchy.

 

And nice selective quoting. Nolan, a semi-professional journalist, also found that the stock ones were twitchy. He rides all kinds of bikes that handle quickly, as do I, and neither of us describe these other bikes as "twitchy." Quick steering and twitchiness need not be synonymous. Several of the early V11s I have ridden were definitely twitchy. They were stock.

[docc]

Hey, mine wasn't "twitchy" when stock, per se. But, it would weave awfully at 90 mph passing trucks and buck and wallow on rough corners. Getting off the original Pirelli Dragon Corsas was a big improvement. Like getting your 'heavy' woman off those 5 inch stilettos!

 

Then: the fork springs, the rear Ohlins, tire choices, the sag, the damping. . . it's all better now, but not before I screwed it all up and crashed in a surprise corner. Too much preload, too hard of a tire compound, too much tire pressure, too much entry speed: BLATT!

 

Are the Red Frames inherently unstable? Oh yeah (more than the later gusseted Blackies).

 

Like an early Honda 900RR? Yeah, right. Like the V11 is a 'crotch rocket.'

 

Is your swingarm perfectly centered? Don't count on it!

[Paul Minnaert]

I'm currious too, to know too why they changed the v11 sport frame. I have allways thought it was bad press. At the time the german magazines had bad things about it. And just at that moment Aprilia took the factory over, and wanted to make an end with te bad press. But they changed not only the frame angle/lenght. The front engine-frame mount is made stiffer, and more important, the rear part between engine and frame is made more stiff, with the extensions to the engine. That last change is the most important one I think.

 

My Daytona has a even one degree steeper angle then the v11 sport. And doesn't do strange things. But more things changed so this is no good comparison.

[motoguzznix]

I agree the attachments to the engine was the most important change.

 

Mine weaves above 150 km/h. It was better with the BT010 tires, I think they are soft and show good dampng effect.

At my opinion, the insensitive front fork is the main reason for this. My forks do not respond to slight bumps, so the bumps are transmitted into the frame.

 

Time is coming soon to evaluate my theory, as I am converting my suspension to Öhlins. In two or three weeks I hope to be back on the road.

[Guest ratchethack]

I do not know of anyone killed on a V11 because of wobble, but I bet if I investigated with the engineers about why the change was made, I'd find that there are crashes behind it. I'll get to that when I have time to update "Big Twins," hopefully soon. I can tell you that that's why the earlier bikes were fixed, not because some journalista said they were twitchy.

 

And nice selective quoting. Nolan, a semi-professional journalist, also found that the stock ones were twitchy. He rides all kinds of bikes that handle quickly, as do I, and neither of us describe these other bikes as "twitchy." Quick steering and twitchiness need not be synonymous. Several of the early V11s I have ridden were definitely twitchy. They were stock.

Hmmmmmmmmm. . . Yet another semi-professional Journo. . . You say you've not actually investigated this. . . That would put the basis of your beliefs somewhere between raw speculation and belief in demon possession. Why not call your Pal Dr. John and get his take on the eeeevil "twitchy" short frames before you update "Big Twins"? While you're waiting for him to return your call, lacking any credible support for your beliefs, might as well continue to perpetuate the Old Wive's Tale of the haunting of Short Frame Sports and Rosso Mandellos by the mythical Twitchy Demon.

 

 

Tough to shake off a nasty twitch, ain't it?

 

We actually had a poster years back, evidently a rank novice rider, who had purchased a PO'd 2000 Sport. By his account, he was mysteriously thrown off on a straight section of road with a few ripples in it. He had no idea what the cause was, or if, how, what, or whether the suspension had ever had anything done to it, and evidently didn't have the faintest clue that there existed such a concept as suspension setup. But he had got wind of the Old Wive's Tale of the "twitchy" short frames, and sold the bike off, evidently convinced it and all short frame Guzzi's are haunted. . .

 

And so the Legend of the Twitchy Demon haunting the Short Frame V11s continues -- even to this day. . .

[Guzzirider]

I rode two different early versions of the V11 Sport shortly after it was launched in 1999, and yes both wobbled like bastards at speed. In comparison my 1100 Sport Corsa which I owned at the time was straight as an arrow.

 

I know the early V11 Sports can be tweaked to make 'em rock solid, but both the stockers I rode were awful over the ton.

 

Guy

[Guest ratchethack]

I rode two different early versions of the V11 Sport shortly after it was launched in 1999, and yes both wobbled like bastards at speed. In comparison my 1100 Sport Corsa which I owned at the time was straight as an arrow.

 

I know the early V11 Sports can be tweaked to make 'em rock solid, but both the stockers I rode were awful over the ton.

 

Guy

Guy, had you noticed if the suspensions on either of the Sports you rode were set up properly? Sags and spring rates known to be anywhere near correct for your weight? (Neither fork springs nor shock spring were anywhere near close to a match for my weight as my Sport was shipped from Mandello.) Did you note if proper size tires were fitted to the wheels? (Mine weren't correct from the factory.) Did you note if the fitted tires were known to be stable at speed on other moto's? (The tires I actually favor now on my Sport have no center groove on the rear, and impart a slight weave at 90+ mph to my Guzzi -- and all other moto's as well.) Were they fitted with steering dampers? Did you use them?

 

Enquiring minds. . . (well, you know). . .

[belfastguzzi]

...and yes both wobbled...

and also, did you note how many jellied eel pies had you eaten before riding those poor bikes? Too many, I'll warrant.

 

 

Besides, you can't keep a Jackal upright

[Guzzirider]

I was about 160lbs in those days a wee slip of a lad. Quite simply Ratch both bikes were a couple of weeks old I had just borrowed them because the wiring loom had burnt out on my sport Corsa.

 

I wasn't the only person to notice the high speed instability. As I said previously I know they can be tweaked but out of the crate they were unstable at high speed on a smooth straight motorway.

 

Not a criticism just a fact

 

Guy

[macguzzi]

No it's mathematics

[Guest ratchethack]

I was about 160lbs in those days a wee slip of a lad. Quite simply Ratch both bikes were a couple of weeks old I had just borrowed them because the wiring loom had burnt out on my sport Corsa.

 

I wasn't the only person to notice the high speed instability. As I said previously I know they can be tweaked but out of the crate they were unstable at high speed on a smooth straight motorway.

 

Not a criticism just a fact

 

Guy

Guy, I fully accept your account as 100% fact, my friend.

 

It's my contention that the short frame Sports have unfairly suffered from improper analysis and evaluation due to ignorance and neglect of proper suspension setup (out of the crate or otherwise), compounded by woefully inadequate spring and (occasionally) poor tire size selection at Mandello -- as has been the case with other moto's.

 

It's always been my contention that every moto design deserves at least SOME attention to proper chassis and suspension setup by those who profess anything resembling objectivity when broadcasting their handling analysis. Without this, no moto ever made ever stands a chance of performing as engineered. And yet, as we have continually seen demonstrated on this Forum, in the moto rags, and by riders all over the planet, blanket statements are routinely made without any attention to suspension setup wotsover. It's generally neglect of such critical attention that all but guarantees bad handling performance. So what amounts to groundless, empty rumors and hearsay based on improper setup are easily and often transfomed into disinformation, which, given further encouragement by heaping more unqualified information on top of unqualified rumor, ensures that such delusions as the Legend of the Great Horned Twitchy Demon haunting the Short Frame V11s continues. . . .

 

 

The Demon is often in the Eye of the Beholder

 

. . . So it goes, and waddayagonna do? . . .

[belfastguzzi]

. . . So it goes, and waddayagonna do? . . .

just now, I'm thinking of going home