tank slap v11 sport

[Guest ratchethack]

Guido, how much, if any, had you raised the fork tubes in the triple clamps?

[RacerX]

While I don't disagree with what Todd said in his post, his ideas make the best of a poor situation,  I would like to suggest there is a much better approach. Rather than putting band-aids on the problem fix the source. I have been told the stock fork spring is rated at 0.60 Kg/Cm. The replacement used by average size folks is 0.90 spring. Heavier/ more aggressive riders are using 1.05s.

 

Lex, I agree we're saying the same thing. I wrote that article back in 2001, when not many people had ever been into the forks. Alot has changed since then... including my GMD Computrack'ed USD Rosso Mandello front-ended Jackal. I'm currently using .95kg springs (pretty damn stiff), and have yet to have any V11S rider pass me yet. Unless you weigh well into the mid-200+# range, or are racing, I wouldn't go to 1.05kg. Leave this to the folks that know.

The '02+ newer "short-framed" V11S' do not seem to suffer from this softly suspended issue.

 

The best known shop in the US: Race Tech

 

I disagree... and I'll leave it at that.

 

I hope Guido and his bike heal quickly.

 

I agree. Hope you have a fast healing New Year.

 

ToddGuzziTech.com

[Guest davidb]

I weigh 225# plus have 20# of junk in my bags on my "2003" (probably a 2002, Exterior fuel pump) V11 sport. I noticed that I can't ride with no hands (to zip up my jacket etc) and the front end is light and a little wobbly in fast hard cornering above 60 mph. Should I replace the springs in the forks and where do I purchase them at?

[tomsp]

Hey Dave! what do you have your damper set at? Is it zero or clicked up some?

 

I put a couple of clicks in mine which seemed to tighten up the steering in those tight turns-- before I did that, my '03 felt totally wobbly like you said. It's seems ok since then with a couple of clicks in.

[Guest davidb]

two clicks. I have messed with the settings but I could never get ride of that light front feeling and the little bit of wobble. I think I might try the racetech springs.

[Dirtybill]

My 0.2 cents.

 

I can feel my steering damper working depending on how I adjust it. I NEVER back it off all the way. I figure it's there for a reason and when I'm out riding I set as stiff as I feel is comfortable and then back it off for slow speed stuff like city riding.

 

I can't help but feel you may have come across the perfect conditions for a tank slap, with bumps, new pavement (slippery) and your damper backed off. Still, the bike shouldnt have gone down.

 

1 other thing I'd like to address. I also own an 02 R1. It came with Dunlop 208s. There's a particular road near here where I take my bikes out after doing tire and or suspension changes just to see how it feels. A straight stretch where I can acclerate as hard as I want had caused the R1 to do a minor and very short tank slap, and I even hesitate to call it a tank slap. More like the bars moving quickly for a split second. This happened when I ran over the bots dots, they're the little reflectors they insert in the centre line.

 

I changed tires to Pirelli Diablos and this mini tank slap disappeared. Same speed, same section of road. The Diablos dont last long on the R1 but in other respects, they are amazing tires.

 

Just a bit of food for thought that may suggest it was a combination of things instead of just one thing that contributed to the crash. Heal quickly

[dlaing]

I don't know what caused this accident, but it seems to me that at 100KPH it was not the spring sag or the damping setting.

I would think that something more serious must have happened.

Are the tires deformed?

Did you feel speed wobble?

Could the brakes have locked?

The rear hydraulics can burn on the exhaust if not clipped in and if the pistons are sticking the fluid can heat and lock.

But you don't appear to have one long skid.

Could the steering damper have locked up???

Could your engine have locked up?

I am no expert, but your skid marks seem to indicate that you were traveling faster than 100KPH.

Maybe I am wrong, but that hill looks kind of steep.

When you changed lane position were you doing it quickly, like you were feeling out the countersteering or scrubbing the tires?

[callison]

You may have had a front wheel bearing failure. Very difficult to evaluate something like this, especially when there have been no warning indications in advance.

[robbiekb]

oh man that sucks and gives me the heebie jeebies seing a bike jsut like mine all messed up

please let me know if you need any stock parts ..i have a few bits and pieces i no longer use. If you end up parting out the bike please let me know, as i could use the tank and other bofy bits for a project that i'm about to start.

 

heal soon

 

robbie

[guido]

I don't know what caused this accident, but it seems to me that at 100KPH it was not the spring sag or the damping setting. I agree.

I would think that something more serious must have happened.

Are the tires deformed? no, the tires are fine, the rims are fine apart from a couple of scratches on the front.

Did you feel speed wobble?I felt absolutely nothing!!! I was going and the next moment I was sliding on the road. That's it! In retrospect, there was something wrong for a split second before, because I remember looking down and thinking what the f****, I seem to remember a buzz like a sound, but it was so short it could be my imagination!

Could the brakes have locked? Yes, they could have, or the motor or the box, I don't know, the reason I have not included these options are that I didn't see any skidmarks at the start of the fall.

The rear hydraulics can burn on the exhaust if not clipped in and if the pistons are sticking the fluid can heat and lock. Funny enough, that happened on a test bike I tried, but I initially thought I was running out of fuel on the unit. It came graduallly and was not dangerous.

But you don't appear to have one long skid. No, that's why I assume tank slap, there were no skidmarks. But, as I said, I noticed no skaking or anything, suddenly I was just on the road.

Could the steering damper have locked up??? The steering damper moves, but has broken the rod on the unset of the threading in the first thread groove.

Could your engine have locked up?Yes, that is also possible, but again, I noticed no skidmarks, and again, there was no warning. In any case I was driving with the fingers on brake and clutch, and had there been any warning, I would have been able to do something.

I am no expert, but your skid marks seem to indicate that you were traveling faster than 100KPH. I can of course not tell you exactly how fast I was going, but I,m running this bike in, and the rest of the trip was between 110 and 130, round about 4000RPM. Nice leisurely trip. Normally, when I notice anything out of the usual, dog, open gate, dirt on the road, parked car, my instinct is always to grap brake and clutch, roll off the throttle and look past the direct problem to the road ahead, while keeping the problem in the corner of my eye. Sounds weird maybe, but this a routine which has stood me in good stead for 30 years at about 50000km on black bombers, BSA, Mirage, Norton and Motor Guzzi. So my guess is about 100, it could actually have been less. If you look at my attire and my wounds, they are minor. I was wearing normal jeans, short sleeved shirt, windbraker out off some modern breathing artificial suede?, lightly padded with a thin layer of white fluffy insulation. Helmet and good leather shoes. Helmet untouched!! left hand grazed along little finger and ridge, slight wound left elbow, small wounds both buttocks, right leg and arm as on photo. I don't think it could have been faster.

Maybe I am wrong, but that hill looks kind of steep. no the hill is not steep at all, my guess is 1 in 15, I was going up hill.

When you changed lane position were you doing it quickly, like you were feeling out the countersteering or scrubbing the tires? Not at all, slow planned move to avoid trouble.

In retrospect I should not have called this a tank slap, because I don't really know what it is/was. The reason I did, was because there were no skidmarks as from a locked up motor/box, and because the stops on the lower fork clamp are both broken, left and right, indicating heavy steering movement. In retrospect these movements could have been caused by the careering down the road. the skidmarks you see are slidingmarks as the bike went down, from back and front wheels I assume..

The guys from Moto Guzzi did not make it yesterday, and I'm not going to start fiddling with the bike before they come. Before we do that, we won't know. I just hope there will be an answer, because I am not going on that thing again without knowing what caused this. I pay for it to go to Moto Guzzi to get fixed, they should have the knowledge to also give a good idead of the cause(s)

39992[/snapback]

[GuzziHutch]

Is it possible that road conditions contributed to this accident? A little bit of diesel fuel can be near invisible on the roadway and yet result in an extremely sudden, violent accident. Unfortunately I speak from experience. Fortunately it was 3 years ago and led to my meeting my wife!

 

Joe Hutchens

[Guest Bruce]

Quido,

 

Based on your latest input maybe it wasn't a tank slapper. Having watch a number of racers do it and from personal experience a slapper is quite apparent. The bars snap violently side to side, hands come off the bars despite your very best efforts, then it's a short awkward flight to the ground. This you'd probably remember.

 

I hate to even suggest it but any chance you had a touch of vertigo? It's more common than you might think and can cause you to go from perfectly normal to on your ear totally without warning. If they don't find anything on the bike you might want to visit the Dr.

 

Good luck

 

Bruce

[Guest davidb]

The diesel fuel theory sounds about right. I had that happen on my old beemer. It was like the tires just went rubber side up. Nothing you can do to stop it. All within a split second. I had witnesses who said the same thing.

[Guest tiger956]

OUCH!!!!!!!!!!!! I fell in mexico on diesel fuel along time ago as a kid racing across the mountain range and as i'm rebuilding this Moto Guzzi LeMans i'm having second thoughts about the handling of it...My Aprilia Falco handles like it's on rails and the Aprilia Mille handles as well as any motorcycle ever made.....I hope it was diesel fuel and not an under-designed motorcycle... gary

[Guest davidb]

I was fiddling withthe tps (set it at 475mv. ign on. engine NOT running) and tightened up the rear shock spring (and every thing else) after reading the factory settings. I am kinda heavy for the factory settings. It is raining here pretty good, so I put extra crash protection (bohn back protector) and really SPANKED the guzzi hard. I live in the low mountains with lots of twisties, so there is plenty of debris on the roads plus fresh pot holes. I don't believe there is a inherent steering problem with the guzzi. I am quite sure there is a set up problem. I know that when I bought my BMWBCR they asked my weight to set it up. The guzzi people only asked for the cash.( but only half as much as the bmw) If there was a design problem with the V11 sport, I would be picking up pieces of it today. I still want the race tech 1.0 springs.