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General Category => General Discussion => Topic started by: szasz on July 01, 2015, 07:56:02 AM
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Just over three weeks ago I was on my Griso 1200 8v and my wife was on her V7C 2009 which she has ridden for the last 5 years and roughly 20,000 kms. We were on a familiar, empty nicely paved highway in fine weather when all of sudden I heard via my helmet’s intercom a scream. Looked back in my mirror and my wife had fallen and was lying in the middle of the two-lane highway. Fortunately, two cars stopped and blocked further traffic. She was travelling at about 90km/hr. She and the bike fell and slid in a straight line and didn’t hit anything. Fast forward - she has 7 fractures between both of her feet and had surgery to put a pin near one heel. She is already in rehab and is expected to make a full recovery. Only one small patch of road rash. Her gear minimised damage. We feel very lucky.
QUESTION: We still do not know why she fell. She describes what sounds like to me like “tank slap”. She said all of sudden she felt the handlebars move from side to side and then she crashed. The police and I could not see any dirt or objects on the road. She’d already travelled 100kms on the bike that morning. Bike seemed to be in good order. We do not “wrench” but have our bikes serviced regularly.
Is the the V7C susceptible to tank slap? Any other possibilities? Here are photos of the bike after the crash. I’m most interested in finding out the cause of the crash. I’s also like to hear opinions about repairing the bike. But mostly, I’d like find out why she crashed. She’s an experienced and competent rider and she was riding starlight in ideal conditions.
Photos of bike: https://www.flickr.com/gp/fukuoka-now/4j8x3K (https://www.flickr.com/gp/fukuoka-now/4j8x3K)
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wow, glad to know she's recovering. How did the fork brace crack? did the bike hit something after it went down?
I can't even guess at the cause but that fork brace was really whacked it looks like. and the rim also got a huge hit, no potholes on the road?
I hope your insurance totals that bike, the frame could be damaged. repair is gonna cost a lot.
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Was she accelerating or decelerating? Did she hit a pothole? Did she run over something in the road, like an animal? Was she swerving to avoid something in the road?
Did you say you were riding at night? Could she have dozed off for a moment?
That bike looks like it took a helluva hit when it went down. Did it slide into a curb?
Unfortunately, there's probably no way to know for sure what happened, if she cannot tell you. And, it sounds like she can't really offer much detail.
I've never heard of a problem with tank slappers on V7s. My WAG is she either hit something in the road, or induced something herself to cause the wreck.
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Did you check the tire pressure prior to riding? A tank slap at speed is a terrifying experience. Hitting the brakes will almost guarantee a crash.
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Had you or she made any modifications to the suspension or is the suspension stock?
If the suspension is stock, I will refrain from asking if her weight is in the correct range for the stock suspension.
Tire condition?
I ride a V7 Stone so I'm very interested.
Hope she recovers quickly but foot injuries are particularly difficult since you can't walk.
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Hoo Wee.. if it didn't take one hell of a hit after the crash.. not likely.. she hit a huge chuck hole or rock to do that kind of damage to the fork brace and wheel. At any rate, that's my best guess.
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The massive rim dent indicates to me that the wheel hit something big on the road. Everything else would be a consequence of that. Hope for a speedy and full recovery, including the confidence to get back on a bike and enjoy it.
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The level of injury is sufficient that you might consider looking into a forensic investigation focused on the machine. The only time I saw that done was in a pickup truck straight road accident. Through analysis of the left front lower A arm, marks on the tires and vehicle, and marks on the road, the analyst determined that the metal of the lower A arm was flawed, it had cracked in part and the rest bent, which put the truck off the road without warning. This finding led to a very substantial settlement that allowed the young driver several years of recovery time and a residual income to help compensate for his injuries. Without the analysis, the burden would have lain upon his family and the production system that generated and did not catch the fault would have remained unchecked.
My great sympathy. My ex and I have both had motorcycle related lower extremity injuries that were not our fault at all. It is a long and painful road. She is lucky to have someone level headed to help her through this.
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Friend of mine, recently, on a new Kaw Concours crashed.
He has huge mileage and experience, lots of miles already on this bike, always ATGATT.
He was on a straight, wet secondary road. He says that the rear wheel started coming around and that's all he remembers, doesn't remember the crash itself. His helmet whacked the road and he woke up in the hospital with a concussion and a broken collarbone.
No way to know what actually happened.
With your wife, the head shot, adrenalin, and shock probably wiped out (like the guy above) what actually happened. From what you've showed us, I think she hit something, maybe something that dropped or ran into the road after you passed. If a bike's front tire blew out and it just fell, you wouldn't get all that damage ....
Lannis
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I think she hit a rock or similar in the road. The impact damaged the wheel, cracked the fork brace and sent the rock flying off the road. Frame, or more likely a triple clamp, may be bent. Suspect internal damage to the tire.
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Yeah. Steel rims don't just bend themselves. It took a big hit.
(https://www.flickr.com/photos/fukuoka-now/18700904634/in/album-72157652986073033/)
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OK....this is out there from a "newbie".
But I just purchased a 2016 V7. It is extremely susceptible to oscillations/side to side "hunting" that seem to be related to the tires. There is no vibration at highway speeds, so the typical out-of-round tire carcass doesn't seem to apply.
But....on the right stretch of road...about 30mph....just riding straight....it feels like the rear tire starts to hunt side-to-side in increasingly stronger oscillations. I'm not sure how far it would go, but in its mild-to-medium form, I have to stop it from directing me into oncoming traffic. It's as if you're riding down the road and sort of wiggling the big side to side for fun -- but if it's just coming from the bike and you're not causing it, it's not that much fun.
The onset of this oscillation can be rather fast. With the first few, you think the bike is just responding to road surface or a crosswind....but then it continues and can get stronger quickly.
The worst happened when the front tire was about 34lbs and the rear was 38lbs (these are estimates as I could only measure them when they were warm). Factory recommends 36 on both. I felt it slightly even at 36....so yesterday I increased the pressure to about 38 each. I didn't feel anything on the next ride...but want another ride or two to decide.
I've ridden on and off since 1983. Never felt anything close to this other than one time when a rear tire was going flat and I got some odd/vague handling. But these tires were definitely not going flat. If the tire pressure doesn't cure it....back to the dealer it goes.
So, although it's a stretch, it's not impossible that an oscillation like that started with your wife and increased rapidly. Depending on the condition of the bike, you might measure the pressure in the tires with a good gauge.
Good luck in finding out what happened.
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.it feels like the rear tire starts to hunt side-to-side in increasingly stronger oscillations
Check swing-arm bearings.
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IMO, the bent front wheel is a key factor. Pothole, rock, junk in the road that she didn't see, etc.
Someone mentioned head bearings and they can certainly cause this but I would think that she would have noticed some wobble in earlier rides before they got bad enough out of adjustment to cause a major tank-slapper.
Only had a tank slapper once in over 750k miles of riding and it was on a 1985 BMW K100RS. I had new tires installed and the shop worker at the BMW dealer installed the front tire going the opposite rotation than marked. I got about three miles from the dealership and was going 55mph on a CA freeway when it started going bazonkers. Fortunately, I got to the shoulder without a problem and took side streets at low speeds back to the dealer.
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... I just purchased a 2016 V7. It is extremely susceptible to oscillations/side to side "hunting" that seem to be related to the tires.
Strange, my '16 V7-II Stone is pretty stable at all speeds, as was my previous '13 V7 Stone. The '13 had Metzler Lasertecs and the '16 has Pirelli Road Demons. Although the two tires do ride a bit differently, I've never experienced hunting, oscillations, or anything else that I would call instability. Nor is the ride overly susceptible to tire pressures, within reason. Especially since your bike seems to be new, I'd have it thoroughly checked out.
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No way that rim and brace got damaged during a slide. That's a hit of an unidentified hard object.
Best wishes to her.
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Best wishes for a speedy recovery. I have experienced mild front end wobble after a hard acceleration or when closing throttle, nothing close to a tank slapper. I think in my case it is a combination of tire pressure and suspension. I have installed new front springs and a Matris adjuster kit and I need to get that dialed in. I'm hoping that will eliminate my minor wobbles. As for your wife's major slapper, I'd have to agree with others speculations; tire condition/pressure or road hazard. Since you know the location of the crash you can eliminate road conditions unless it was some foreign object that might have since been removed or animal but you would have seen evidence of that as well. I do know of one other Gent that experienced a major tank slapper on this forum but he was riding hard and road conditions were very poor so it isn't a direct comparison.
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Good to hear that your wife will be OK.
Have to agree with most others - the only way the rim could bend like that and the fork brace crack is with a hard, hard impact - not dropping the bike.
Something heavy and hard was most likely on that road and,as has been guessed, kicked off to the shoulder or farther.
My suggestion would be a real thorough search of the area on either side of the road.
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In reviewing the photos provided I noticed that a majority of the crash damage appears to be on the right side of the bike with the exception of the bent left portion of the handle bars. As evidenced by the bent rim, and lack of pavement or concrete debris caught between the tire and rim, it appears some type of impact initially occurred to this side of the bike while it was in an upright position. With no "sharp indentation" and lack of any pinch marks on the tire sidewall, it would appear the impact was with a rather large object. There does however appear to be a scuff mark on the sidewall of the tire just behind the bend in the rim. Usually an impact even with a large animal will leave some type of evidence such as hair, skin or debris. It appears the force generated from this initial impact caused the handlebars to suddenly move to the right and in a downward motion. At the same time as evidenced by the downward bend of the left handlebar, it appears the rider struck this portion of the bar as she was ejected over the left side of the bike. This twisting motion possibly caused the fork brace to fracture. The accumulation of debris between the right side cylinder fins, which appears to be asphalt, probably occurred as the right side of the bike came in contact with the pavement. The brake pedal being bent in a "rearward" direction combined with the scrape marks to the exhaust system and valve cover would suggest bike continued sliding on its right side. I am by no means an expert in crash reconstruction and only offer the above as a possible explanation as to what occurred during the incident. I sincerely hope you wife recovers and can ride again in the future.
Jerry
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On a 2009 V7 I'll get a mild wobble at 80 mph, but only with full saddlebags and my hands off the bars. And it's only under those conditions: 80 mph with full bags and no steering input.
That's my 2 cents. Hope your highway dept does a good analysis.
I used to be an accident reconstructionist for the state police. Had one case where an experienced rider on a well worn large Honda went down at high speed on a dry, level 4 lane divided highway during daylight with no traffic. Bike eventually slid into the guardrail, killing the rider. Bike suffered little damage, and appeared still rideable. I thought about a test ride, but was genuinely afraid of a bike that had already killed.
The only witness was a man in a car. Interviewing troopers thought the man and rider were "playing" with each other, but couldn't get him to confess to it.
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Looking at the pictures my best guess would be a sharp cornered chuckhole with the edge at a slight diagonal to direction of travel.
This would dent the rim and impart a twist to the steering head.
I was riding with 1 1/2 inches of fresh snow, very soft and fluffy but capable of hiding the diagonal railroad track that crossed the road.
It was dark night and I hit the rail at about 35 MPH. It literally kicked the bike from under me. It felt as if someone had kicked my front wheel from the side. I was only bruised because the snow greased my fall to a harmless slide after impact.
If you return to the scene you may find a ridge of pavement or chuckhole, or possibly a piece of debris.
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My 1982 Mold Wing, a GL 1100C would wobble at any of three speeds: A single cycle oscillation of huge magnitude - "steer into it hard!" at zero indicated road speed, a more classic 45 mph tank slapper that scared the pudding out of me more than once, and a 70+ lane width using shark like motion. Fortunately only the really slow one ever planted me, and there were friends to assist hoisting the great maroon whale back upright.
Between my mechanic and I we: changed tyre pressures, checked bearings - wheel, steering, swingarm, altered suspension pressures fore and aft, checked tyres rims and brake rotors for any runout, loosed and then retorqued each and every critical fastener on the machine, added a fork brace, removed windscreen. Naught, zilch, nuttin. Wobble there until I sold it cheap and walked away happy.
I think it was inhabited by a dybbuk.
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I think it was inhabited by a dybbuk.
Fruma-Sarah Wolf, I'm guessing.
Although in that bike, it may have been Golda-someone ....
Lannis
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:bow:
You got the reference! Happy happy joy joy!
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Check swing-arm bearings.
Right, and also head bearings. Play in either will encourage instability. Wheel bearings too, for that matter. (referring to MGPilot's post, not the orignal post)
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First of all, thanks to everyone for their kind wishes for my wife's recovery. As I wrote, all things considered, we feel we were very lucky. Fractures in both feet mean no mobility for a while, but she will recover well.
Thanks for all the suggestions as to the cause. Unfortunately she doesn't remember anything except the shaking handle bars.
As I wrote, conditions were ideal. The bike did NOT hit anything after the initial loss of control (i.e guard rail, other vehicle). I found it in the middle of the road. Air in both tires. I was to busy staying with her and calling for help that I didn't not check road surface at the exact location of the fall. She might have hit something, it is a possibility I suppose, but the cars behind her, nor the police who inspected the scene found anything. The wind was light. There is a cut between the two lanes in the road. But she is an experienced rider and the cut is not enough to be consider a hazard. The tires are fairly new and well inflated (still).
Some have noted the large dent in the rim - that seems puzzling to me, as the bike ws found in the middle of the road. Maybe it flipped? The bracket between the front forks is broken on both sides too.
Several people have suggested checking bearings. I think I will.
Thanks again,,,
Nick
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Are the forks cracked near the axel from overtightned pinch bolts? There were not pictures of that area. I crashed one I believe from that . Best wishes for a speedy recovery!
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It has been a short as in quick 55 years since I left Japan but the time has not erased my vivid memory of the evil " benjo ditches". Which may be the problem looking at the damage and the fact that she has bones broken in both feet.