tank slap v11 sport

[Guest markbar]

I thought the swing arm and rear wheel geometry was changed after the first series v11? Was the swing arm lengthened? The high speed handling was certainly less prone to wobbles on later series.

 

Have been looking through this forum recently, very interesting and relevent topics, thx to all involved.

[guido]

I thought the swing arm and rear wheel geometry was changed after the first series v11? Was the swing arm lengthened? The high speed handling was certainly less prone to wobbles on later series.

 

Have been looking through this forum recently, very interesting and relevent topics, thx to all involved.

48041[/snapback]

 

Regarding the bike, I am aware that the front fork angle was changed back to 26 degrees from 25. This in itself will give you longer wheel base. Then I know the back fork has been re-inforced. If it is any longer, I doubt, but I don't know. The reduced wobbleness I think is mainly attributable to the front fork protruding further to the front, and then a firmer back from all the stiffening. The longer wheelbase in itself also gives you a more docile creature.

[Paul Minnaert]

I thought the swing arm and rear wheel geometry was changed after the first series v11

No it wasn't. Same swingarm. Only the between engine and swingarm pivot there are extra braces with the newer models. The forks angle is indeed changed, and the frame is a bit extended to the front.

I changed my daytona the opposite way. 24 degree head angle, 1430mm wheelbase. And still no problems on the road with stability.

[jihem]

I didn't first have tankslapping problems on my GB Supertwin as the handling and stability of that bike was flawless when i bought it new.

the bike was sold with Dunlop 207. later, i changed them to Dunlop 208, and problems started there: a few hundred kms after i got the new tyres, i could feel the bike being a tad nervous on junctions and motorway ramps and access: the front would wobble slightly. It only got worst to the point where i couldn't ride hard the STW no more, and then even when riding 'calm" the bike would start dancing around...The tyres were still good and looked fine.

But i was so scared, i decided to changed the front 208 by a new 207.

all the wobblings are gone now: the front tyre was 'just' being worned in small, nearly invisible steps...Problem is: you could hardly see the front tyre was f*cked...

[guido]

Just an update.

SKF seem to have done an exellent job of cutting my front wheel bearings open. They can see no fault on the bearings.

I am thus back to square one. What caused the buzz just before the fall?

[jrt]

Curious.

Umm, just a random thought here, but the brake rotors are drilled, and I hear a 'buzz'- albeit a soft one- every time I brake. Could your brakes have siezed up or expanded/been applied somehow?

J

[Guest ratchethack]

Guido, many of us, particularly owners of the "short frame" 2000 Sports, including myself, have followed this thread from the beginning with great interest. There's been lots of speculation as well as well-founded anecdotal experience weighing in -- both here and still linked from this thread on the WG board. Personally, as I've posted on this topic from time to time, I've been most concerned about the persistence of false rumors of instability supposedly inherent to the "short frame" Sports, which I have always believed to be -- well, frankly -- hysterical mythology. Such rumors have always been, after any kind of basic analysis, without any foundation whatsoever in my opinion. I've been paying very careful attention to this -- since long before I bought my Sport.

 

I have yet to discover a single well-documented case where any kind of handling anomaly has occurred with these bikes where basic suspension setup is known to have been credibly performed, as would be minimally expected for the safe operation of any motorcycle. If the suspension setup is unknown and/or ignored and THEN there has been a problem, all bets are off -- and rightfully so. Again, this is exactly as would be reasonably expected for the safe operation of any motorcycle.

 

As recently as July of this year, you had posted:

I, for one, think there are problems with the old frame. And looking at the developments at Moto Guzzi, so do they. The main weaknesses apart from the suspension and the tyres, imho has to do with the standard Mazzochi front forks, the steering damper, the front fork angle and the rear swingarm.

From a more recent thread that you may have missed on this topic in answer to a poster interested in buying a "short frame":

Many "sporting" bikes have a more agressive rake, including the MGS0-1 at 23.5 degrees, and the new Ducati Sport at 24 degrees. Later Sport and LeMans variants have a relatively lazy 26 degree rake. The rumors have it that there's a "frame problem" with the 25 degree Sports. The BIG LIE is that the 25 degree "steeper geometry" causes speed wobbles, head-shakes, tank-slappers, heat rash, jaundice, jungle fever, prickly heat, gout and piles. The most egregious versions of these unfounded tales of woe maintain that the "short frame" Sports will throw riders off spontaneously and without warning on straight sections of road!!! These patently false rumors have been wreaking havoc among those who're not knowledgeable enough, and among those who're for whatever other reason unable to confidently debunk them. Those who own them (myself included) have largely rendered themselves immune to the BIG LIE with knowledge and the application of a moderate dose of reason and common sense.

As far as your opinion on additional "main weaknesses" of tires, Marz forks, steering damper and swingarm, may I ask what specifically -- if anything -- these observations might be based on?? All of these components are common to many kinds of Guzzi's, and with the exception of the swingarm (common to all V-11 LM and Sport variants) all are common to other bikes from other marques as well, none to my knowledge having any such rumors attached!!

 

I sympathize with your situation, Guido, because you've been through the wringer on this, but the unsubstantiated rumors have been of no help to you -- quite the contrary.

 

If I remember correctly from when my own trans recall work was done, one of the factory caveats in the wording of the recall itself was that sudden locking of the rear wheel was a potential outcome of not having the recall done. Looking back with the benefit of 2 years' hindsight today, in light of your recent discovery of transmission problems apparently due to a recall that had NOT been done on the bike in question prior to your crash (am I understanding this correctly?), do you now have a different perspective?

 

I'd sincerely appreciate your feedback. Many thanks.

[dlaing]

The only instability I had was from a rear tire (brand name withheld as I am sure it was just lemon of a tire).

Solution: lowered front end and it got a little better. The wobbly feel starting at 100MPH instead of 80MPH which kept me happy till I replaced tire

FWIW, I now swear by Pirelli and Metzeler, though I am sure there are other good tires out there, my testing has given me a bias for these brands.

 

Oh, yah, and once I got air born for a one mississippi at 120Veglia MPH, landing rear first and then when the front came down I fought off a potential tank slapper.

Solution: I now try not to get airborn at over 80MPH

FWIW I was using Dunlops at that time, not that that had anything to do with it...

 

Also for what it is worth, I greatly prefer the Ohlins, but my comparison is with Marzocchi that needed respringing.

[guido]

 

If I remember correctly from when my own trans recall work was done, one of the factory caveats in the wording of the recall itself was that sudden locking of the rear wheel was a potential outcome of not having the recall done. Looking back with the benefit of 2 years' hindsight today, in light of your recent discovery of transmission problems apparently due to a recall that had NOT been done on the bike in question prior to your crash (am I understanding this correctly?), do you now have a different perspective?

 

I'd sincerely appreciate your feedback. Many thanks.

 

 

Ratchet, I know I am ratteling your cage, which I don't intend. However, you are looking for an answer, and I can give you this.

There is a problem with the gearbox. It shows signs of having fused on the lower secondary shaft, on the sixth gear. It was free after the accident, because the bike was started and run through the gears on a stand. So it has been a friction induced nip, and things must have returned to normal after the box cooled down. You can see the picture of the damage. And a picture of the road.

The bike has been standing since the accident, and I have only recently had the time and inclination to start getting the bike restored. The damage has nothing to do with the recall, as all the recall parts are still in fine shape. As a matter of fact, the box is as new, it has done 1100km, apart from the damage to the sixth gear and the splines. The gearbox problem is thus not directly related to the recall, but discovered, because the recall had to be done. It seems as if this is a heat seizure, caused by incorrrect tolerances.

Remember before the fall I noticed for a split second a sudden roughness, or vibration? this can explain it. (You can go through the write-up from then)

As you may also recall, the best explanation for the crash seemed to be a tankslap, although I could not recall such an event. But a combination of a bad road surface, a broken steering damper bolt (fatigued) and also a problem with seizure of the box, you take your pick, all could have worked in unison.

Fact is I came off, and I was driving very carefully at that particular moment.

I was looking for answers, because the thing was so unexpected, unprovoked and frankly baffling.

As to the handling of the bike.

1. I am going to modify the suspension.

2. I am going to install a narrower rear tyre

 

As for the handling generally. Well, I can't really comment on the green V11 currently, because I have not been riding it for two years. But I can say this, the Breva 1100 is more stable, more predictable, less wobbly and easier to live with than my later model (2002 long wb.) V11 sport. And from memory, my "new" V11Sport is better than the green one ito handling. The green bike has a lot of character, but it was never the best handler, it would particularly wobble in corners, unless powered through, and it was very sensitive to a change of mind in the corners. This is in absolute contrast to the Breva.

Don't get me wrong. I enjoy my motorbikes, all of them, and I am looking forward to driving the green V11 again. especially since I can now explain, at least partly, what went on during the crash.

And Ratchet, remember, all the good advice and knowledge that has been bandied around here for the last couple of years. I had this bike on the road for about 14 days before the accident. I was breaking the bike in, gently. I didn't have the knowledge of this model I have now, I was just a happy new owner of the first bike I had ever bought new in my life.

It is not to be expected that an average rider should be a suspension expert, or any other type of expert for that matter, to take a stock motorbike for its break-in milage. Checking oil, tyre pressure and safety issues (and loose screws, it is a Moto Guzzi ), is all you should be able to do to the bike to ride safely! Remember also, that this was an accident at a speed of maybe less that 100km/h, on a straight road, no Diesel, gravel etc, no changes, no (active) breaking, and you might understand my surprise, shock, disbelief etc.

 

And I know how strongly you feel about the handling of the early V11. I don't want to be drawn into an argument. Just satisfying your curiosity, I hope

 

[Guest ratchethack]

As you may also recall, the best explanation for the crash seemed to be a tankslap, although I could not recall such an event. But a combination of a bad road surface, a broken steering damper bolt (fatigued) and also a problem with seizure of the box, you take your pick, all could have worked in unison.

Fact is I came off, and I was driving very carefully at that particular moment.

I was looking for answers, because the thing was so unexpected, unprovoked and frankly baffling.

Guido, thanks for your reply. This has been an ordeal, and I appreciate your frustration as the owner of your first new motorcycle. But with all due respect, baffling as this may be, I believe you're still persisting with incorrect conclusions that are not based on known facts, not borne of correct analysis, and not supported by credible history.

 

A tank slapper is something that you wouldn't ever tend to forget, my friend. I've had several on a dirt bike at about 40 mph 30 years ago and can STILL "feel it" in my muscle memory as if it happened yesterday. In each case, I doubt I'll ever forget the helplessness and sheer terror of the very long, but precious few seconds prior to the crash!!

 

If you were to discover a fundamental "problem" with the short frame Sports that, without warning, could credibly and conclusively be identified as the cause of your sudden crash on a straight road, you would be the very first to determine such a cause, my friend -- not to mention potentially being in possession of grounds for a substantial lawsuit! I submit to you that your lack of understanding of the cause does NOT constitute an implication of the vehicle -- but it is, however, under the circumstances, a far more likely indicator that exactly the OPPOSITE may be true -- that is, that the vehicle is more than likely NOT implicated!

 

I don't know how many thousands of short frame Sports have been on the road for around six years now, but to the best of my knowledge, despite the persistence of false rumors, there have been NO well documented cases such as yours, and yours is NOT well documented. I'm sorry, my friend, but for you to have drawn conclusions of a defective design is frankly preposterous. You simply have no conclusive evidence that the DESIGN of the bike was at fault. Again -- Many on this board, including myself, have experienced nary a hint of a tank slap nor speed wobble OF ANY KIND in many hundreds of thousands of combined miles, under all kinds of riding conditions. I don't think any of us consider this dumb luck, do you??

 

As far as a broken steering damper mount bolt, this would be consistent with any crash, particularly where the fork limit tabs had been snapped off, as I believe you had indicated -- as A RESULT of the crash. There is NO circumstance imaginable (to my mind anyway) where a steering damper bolt could have snapped off whilst underway and CAUSE a crash! If it were to literally disintegrate underway, the worst that could happen is loss of steering damping!

 

......The green bike has a lot of character, but it was never the best handler, it would particularly wobble in corners, unless powered through, and it was very sensitive to a change of mind in the corners. This is in absolute contrast to the Breva.

Guido, again -- with all due respect, it appears that you have very little experience with suspension, perhaps none at all. Don't feel bad, you're in good company and among friends here. I suspect that a great many of 'em are in the same boat! But you may not comprehend that riding a motorcycle out of a dealership is not as simple as driving a new car off the lot. With a car, if you don't ever give suspension as much as a thought, you're safe. This is an unsafe assumption with any motorcycle. It's so highly adjustable around so many different parameters for good reason!

 

You may not fully comprehend what "best handling" is, nor understand that "the best handling" can never be expected to be achieved with neglect of correct suspension setup. No new rider is expected to know what this means, but any reputable dealer worth his salt would make a point of going over the basics and at least get the suspension settings "in the ballpark" for the bike's first rider. In all of your posts for two years on this, to my knowledge, you have yet to mention one word of suspension setup. To me, along with your "wobbling in the corners" commment, this indicates a high probability of neglect in this area, and I don't know who may have neglected it, but as the rider, it was YOUR responsibility. Yes, there certainly can be consequences based on probabilities for this kind of neglect -- particularly for a novice when it comes to suspension!

 

Regarding your comparison of handling of your Sport to your Breva, it is a disservice, unfair, and invalid to compare the handling of any motorcycle to that of any other unless the suspension of each is known to have been set up properly. If suspension setup is UNKNOWN, it is correctly assumed to be improperly set up and less than the bike is capable of unless and until proven otherwise. If the front and rear sags (both laden and unladen) aren't within basic parameters, it's not properly set up.

It is not to be expected that an average rider should be a suspension expert, or any other type of expert for that matter, to take a stock motorbike for its break-in milage. Checking oil, tyre pressure and safety issues (and loose screws, it is a Moto Guzzi ), is all you should be able to do to the bike to ride safely! Remember also, that this was an accident at a speed of maybe less that 100km/h, on a straight road, no Diesel, gravel etc, no changes, no (active) breaking, and you might understand my surprise, shock, disbelief etc.

Guido, I don't mean to preach here (yes, really! ) but when you take ownership of any motorcycle, YOU also take ownership of the responsibility for its safe operation. Ignorance is no excuse for lack of basic, safe suspension setup. It's a mandatory, fundamental recommendation of every Pro and every responsible dealer on the planet. Most shops set them up to perform at least adequately for a wide range of potential rider weights and abilities. Do some dealers skip it or get a "less than adequate" match of setup to some riders? What do you think? Is is worth taking a chance to you? Without any preload at all on a shock (or a setting that is at best simply UNKNOWN), for example, with no basis for comparison for the way it should feel and behave, a new rider is simply less than safe, and at risk, and that's a fact. I've seen novice riders regularly bottoming out an improperly preloaded rear shock for years, all the while complaining about poor handling of the bike, having concluded that this is simply "the way this motorcycle is"!!!!

 

The point is that if you don't understand suspension setup, you're obligated to either educate yourself and do it, or rely on a trusted professional who can get it done properly for you. I would hope that if you derive no other value at all from your experience, Guido, that you'll eventually come to understand what this means. Regardless of cause, IMHO your accident is the best evidence you could ever have of how important this is, as well as proof that having it set up correctly could save your life and that of others. The same principles apply to every motorcycle, my friend.

 

And I know how strongly you feel about the handling of the early V11. I don't want to be drawn into an argument. Just satisfying your curiosity, I hope

Guido, I hope that at some point your experience may be of value not only to YOU, but to others who may be reading this, or to whom you may relate your experience directly. But persisting with the "haunted short frame" mythology does no one any favors, and it's wrong.

 

Now I'm not suggesting that neglect of suspension was the sole cause of your crash. I consider this extremely unlikely under the circumstances. Could it have been a contributing factor? I don't think there's any question about it, it most certainly could have, with a substantial degree of probability. I simply don't know what caused it, but I don't think you know either, and you may never know. All I'm saying is that, particularly as a novice with regard to suspension, I believe you are unqualified to have blamed the design of the motorcycle and make the strong implication that these are fundamentally dangerous motorcycles. While far from being the best handling motorcycle by modern standards, my Sport is the best handling and most enjoyable to ride of a dozen I've owned over 40 years, and it's my all-time favorite. I don't think I'm wrong in believing that many on this Forum would say much the same.

 

Regardless of your level of experience, if you're able to achieve proper basic suspension tuning on a Guzzi or any other bike (whether you do it yourself or you have a qualified Pro do it), I can PROMISE YOU that your riding experience will be far more rewarding, far more enjoyable, and far more SAFE! Without it, you will never have an opportunity to gain an appreciation of the inherent handling potential that any motorcycle is designed with and capable of.

 

It's great that you've decided to do suspension work on this bike, and I applaud you for it -- but if I may make a suggestion, don't do what so many others have done and throw the baby out with the bathwater! A properly sprung stock Marzocchi fork is a perfectly good road fork, and it has advantages over an Ohlins fork that some (myself included) consider significant!

 

I can tell you from personal experience that just re-springing my Guzzi alone, which allowed both laden and unladen sag settings to be correct for the first time (front and rear), made a WORLD of difference and transformed the handling. The addition of a custom shock capped it off. I can tell you that if you don't get this done, you'll never get close to understanding the handling that it's capable of. I don't know what you weigh, but if you're of "normal" weight, by far and away the weakest link, and my recommendation as a starting point, is replacing the stock fork springs -- assuming you have the same .6 kg/mm springs that I got from Mandello. It's relatively easily done in about 20 minutes and the cost is usually around $130 USD.

 

May I suggest becoming familiar with the principles at these links as a good start:

 

http://www.racetech.com/articles/SuspensionAndSprings.htm

 

http://www.strappe.com/suspension.html

 

I hope you don't take my opinions harshly, my friend. I'm trying to help.

 

Best of luck to you, Guido.

[Bbennett]

Very sorry to hear of your crash.

 

I have a 2001 Sport and have not experienced any tank slapping behavior and have stock suspension. I do not use the steering damper at all....

 

Bob

[Guest Mattress]

 

I would like to know something. How should one target a spring rate to account for a rider who (ahem) seems to gain and loose 20-25 lbs regularly and also account for luggage and no luggage?

 

Do you aim to have the sag correct for your "ideal", lightest weight with no preload and then use preload when your pizza binges accumulate to higher weight?

 

My first order of business for next season is to set up my suspension correctly for sag and preload. I have an 04 cafe sport with the Oehlins suspension. I used to think the rear shock was too stiff, but I actually think it might be bottoming out. Over even a small frost heave, the front will glide over relatively well behaved, but it is followed by what feels like someone kicking me in the arse. It can be hard enough to upset my throttle hand besides being painful after a long day in the stock saddle.

 

I conclude the V11s aren't quite sprung for my "current" weight of 220 lbs. I'd be a bit bummed if the Oehlins shock can't be corrected with a new spring.

 

Can Oehlins USA help me out? Anybody had them help out?

 

P.S. I bought the cafe sport because it was a great deal. Not to be a squid poser needing fully adjustable gizmos. And I spell it OEhlins when I can't find the umlaut character.

[Guest ratchethack]

I would like to know something. How should one target a spring rate to account for a rider who (ahem) seems to gain and loose 20-25 lbs regularly and also account for luggage and no luggage?

Say MattMan - I don't know wot happened when you tried to quote me above, but it prevented any ability to reply, that's why this looks all improper - like I copied & pasted. . . . wich is wot I did.

 

You gotta watch that weight bouncing, my friend. Not at all good for the ol' ticker. . . .

 

Now to all Racer Boys, wannabees, and sundry other species, this will be pure, demonic HERESY:

 

I have no experience with Ohlins forks, but regardless of fork mfgr., your scenario, IMHO, is the perfect application for progressive springs. I'm here to tell you by personal experience over 3 separate moto applications -- that in practice, the latest trends in the direction of moto OEMs toward progressive springs are well founded. They spread the effective range of load carrying capacity. For the ranges you're considering, you preload y'er laden sags for a weighted average between max and min load based on percentage of riding miles in each mode, and leave 'em be.

 

I used to think the rear shock was too stiff, but I actually think it might be bottoming out. Over even a small frost heave, the front will glide over relatively well behaved, but it is followed by what feels like someone kicking me in the arse. It can be hard enough to upset my throttle hand besides being painful after a long day in the stock saddle.

Sounds way too much like classic symptoms of bottoming out to me, and your [ahem] gravitational endowment would be consistent with this with the stock spring. I've got a Pal with the same exact situation but he's got a few pounds on you: Too low rated spring for the load, preload cranked up in futile attempt to compensate, laden and unladen sags way out o' whack = HARSH ride.

 

Congrat's on plans to make the best mods you'll ever make IMHO. Good luck.

[Guest Mattress]

I would like to know something. How should one target a spring rate to account for a rider who (ahem) seems to gain and loose 20-25 lbs regularly and also account for luggage and no luggage?

Say MattMan - I don't know wot happened when you tried to quote me above, but it prevented any ability to reply, that's why this looks all improper - like I copied & pasted. . . . wich is wot I did.

 

You gotta watch that weight bouncing, my friend. Not at all good for the ol' ticker. . . .

 

Congrat's on plans to make the best mods you'll ever make IMHO. Good luck.

 

Yes, I know it is not good for my heart. I'm pre-disposed to hedonism, whether pleasurable substances or italian food . It's a constant battle. Thank goodness I'm not handsome or hung like a rhino, I'd probably be dead from V.D.

 

I'll look into the springs. The front seems o.k., but Ihaven't set the sag. The rear is a pain and detracts from the bike. Maybe I can even do the sag in the garage this coming month.

[mdude]

sad to hear about the slapper, incidents like that always get me down to the garage to check things over yet again. let the healing begin...

 

Allow me to share my experience, even though I'm a novice when speaking of adjustments:

 

I think this slapping business might be because the way these bikes are set up by Luigi for his little brother; for small and light testriders driving on smooth surfaces (perhaps?).

 

when I bought my 2001/02 V11S Greenie (bought unseen) it was with 7000 kms on the clock, stock springs and dealer setup both on fork and rear shock. and it was plain dangerous! it was so goddam hard and nervous that a coin in the road made it jump 1 meter to the side, I never knew where I was going to finish the turns because any imperfection in the road threw it out of course. Steering it was like feeding chicken to an alligator blindfolded, in this state I worried a lot about tank slappers and had a death grip on the bars at all times. This was on tight B-roads with coarse surfaces. It was just fine riding highways and cruising, but the twisties gave me brownies...

 

Im about 200 pounds in combat gear with gorilla arms and the bike clearly had all its weight sitting on the rear wheel. if I leant aggressively over the tank it got a lot better. first action (after advice from this site) was to back off on the comp and rebound settings all around. a lot better: less nervous and easier to point in a straight line. it still steered both slowly and nervously at the same time, though.

next action: adjust rear shock. I stiffened the spring on the rear shock almost 3/4 to the max, and raised the rear about two-three cms. A LOT better, now it steered where I wanted almost all the time and the death grip was history.

I experimented with the steering damper and found that in this state I didnt have to use more than a click or two of damping. The bike was still a bit slow steering and didnt have a lot of feel through the forks, I didnt trust it all the way.

next action Wilbers progressive 0,9 kg fork springs as recommended by Ratchethack.

Now even better, much more feel and more precise, though the mechanic didnt get the sag right. I'll look into that in spring.

 

I have not had a single moment with anything resembling slapping or wobbling after I turned up the rear shock and backed off on comp and rebound. It just goes where I want like an old steamer. It still lacks some feel and ultimate precision, but I think thats just down to final adjustments. And after all its just an old hotrod...

 

Moral? Be careful with driving this bike straight out of the box. Personalize it!