Like the song "I kissed a gaurd rail".........and didn't like it, tank slapper on G/S

Discussion in 'Old's Cool' started by One Less Harley, May 4, 2009.

  1. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    as a few of you may have remembered that I posted some questions about a slight wobble on the G/S, well here's my story ever so brief. Went to the GA mountain rally and had a slight problem.

    HERE'S MY TANK SLAPER STORY ON THE G/S

    Some people who went to the GA mountain rally might have noticed a guy limping around the event w/ bloody T-shirt Friday about 5-6 PM or during the whole event. At about 100 miles out from Bowling Green, KY, in TN. I got into a tank slapper. Basically doing 50 mph (wobble usually appeared at 65-70), in a right hand sweeper on damp roads, crossed the double yellow which had ripples in the center line, and as I was slowly bringing it back to my lane, the bike being leaned over (just a little, I wasn't going very fast for he slight downhill curve), with the bumps and yellow paint, upset the bike and the tank slapper occurred. I tried to ride it out, but no luck.
    Bike went down, luckily no traffic was coming (very early in morning) as I slid to the left side of the road, still on the bike, HT panniers and crash bars kept the bike off my leg. I remember thinking that at least the bike was in front of me. After that quick thought, my next thought was of the guard rail which I and the bike were sliding to. About 10-15 feet before the guard rail I was separated from the bike, but thinking that guard rail is going to hurt when I hit it. Bike's forks went under the rail and stopped, then I hit my right side just next to the bike.
    Sat up and took physical inventory, felt sore on fore arm and upper arm and top of thigh. Moved arm and new it wasn't broke, but hurt, leg also hurt pretty good. I got up and new nothing was broken. Walked i.e. limped to bike and shut off ignition, when the rider behind me stopped and helped pull the front of the bike from under the guard rail.
    Initially the front end looked F'd, but all we did to get it back on the road was loosen the bars and pull them back, no bent rim or forks.
    Damage to bike- wind sheild, ground down left crash bar, bent up HT pannier, staightened out w/ hammer to remount (btw, who says stock luggage racks aren't strong enough, well w/ the extra gussets I had added anyway), crash bar ground flat, cracked headlight surround, broke right turn signal. That's it for the bike.
    OK- I was wearing a Nitro textile jacket (hard armor in shoulders and elbows, soft armor in back), Olympia Pants, stiff knee armor, soft hip armor, Newly scratched Arai XD3 helmet, thin Heingerike gloves, Sidi ON Road boots. No tears on jacket, and small tear on left pant leg at the boot.
    Physical damage- Hard armor edges cut my fore arm and upper arm when I hit the guard rail, darkening bruise on upper arm, no bruising on fore arm or leg even though my leg was sore as hell the 1st two days, still my leg gives way in pain every now and then when walking.
    Road the the rally but the 1st 30-45 minutes 40-50 mpr seemed pretty fast, still a little shook up.
    Still haven't figure the wobble out, Nathan from Boxerworks confirmed that the rear bearings in the mono lever ring gear have to much play, so I'll be fixing that. If the wobble is still present I'm trailering it to Guenther Wuerst in indiana to have him find the problem!!

    Road back Sunday in 275 miles of rain wobble still present, but VERY cautious.
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    #1
  2. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    update left fork leg is bent, final drive appart and bearings pulled to get #'s for bearing house to see if I can get a better price than from BMW.

    Large bearing $75, smaller needle bearing $45
    #2
  3. bgoodsoil

    bgoodsoil Dare to be Stupid

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    such is the life of a rider
    #3
  4. Cogswell

    Cogswell Spudly Adventurer

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    Wow, glad you are relatively ok and hope you finally get the bike sorted out. I think I remember you talking about the wobble at Renfro Valley.


    Mike
    #4
  5. Kismet

    Kismet vagrant philosopher

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    "Those who have, and those who will."

    Glad you are relatively ok.
    #5
  6. Rob Farmer

    Rob Farmer Long timer

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    Glad you're still here OLH.

    Matkat in the UK had a similar experience with a tank slapper on his g/s. I've also had a few unstable moments on mine when fully loaded at speed. I know others have as well. It may be load induced but it would be nice to know for all our sakes.

    This was Matkats experience (Madmountainman's report on the GSClubuk site) -

    "Ok folks, i've just spoken to Freddie at home. He's laid up in bed, being nursed by the lovely Sue... who's a tad shook up by it all too. He's got some broken bones in his hand, a cracked rib, iffy ankle and various bruises everywhere else.
    He was heading up the M5 on the airhead, loaded for Horizons, overtaking an artic when white van man went roaring by in the outside lane at warp 9.5. The air wake set Freddie's bike off into a massive tank slapper which he managed to hang onto for some considerable time, according to the driver of the artic. Part of hanging on consisted of standing on the pegs trying to weight the front and calm it down, which must have been quite a spectacular sight!
    Inevitibly, Fred was launched off the airhead, over the handle bars, into a 5.9 forward roll and was up and running for his life for the hard shoulder. Fortunately, artic man and another driver had seen all, straddled the lanes and brought the motorway traffic to a stop.
    They got his bike and scattered bits and pieces to the hard shoulder and got the traffic moving again.
    He's lost the front end clocks/headlamp etc, holed both rockers, trashed his Mules and rear frame work. Other than that, it's mostly cosmetic. The main thing to survive though, besides Fred, was the tipi! Just a couple of holes in the bag where the pegs pushed through.
    With the police and ambulance in attendance, you'd have thought his adventure was over, but no! He was taken in the police car to the hospital, but before plod got off the motorway, they were called up to assist apprehending a disqualified driver who was being chased in the area. A high speed chase ensued, i belive the idiot was caught, and Fred was finally transported to hospital following his little racy adventure!!! The hospital staff were somewhat surprised to find a walking, injured bike crash victim from the M5. Apparently they never get walking wounded from bike crashes on a motorway!"
    #6
  7. elmoreman

    elmoreman takin' a break, boss

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    Glad you're OK. Another lesson that its better to fix a small problem before it becomes a big problem--I know youve been working on it and trying to sort it out, so I'm not trying to be a dick, but its a good reminder. Thank god no one was coming in the opposite direction when you went down.
    #7
  8. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    In hind sight I'd have to agree w/ you. I was careful to keep the speed at just below the wobble, but this was way below the woddle speed of 70mph. But a group of factors agrivated an already dangerous preexisting condition.
    Yes I should have had it fixed before ridding it any, as I would suggest to anyone with any sort of wobble, get it fixed and don't think that you know when it can occur and ride outside of those conditions, as a group of factors may change when you "think" you are ridding below the speed or other factors which cause the wobble.
    #8
  9. Foot dragger

    Foot dragger singletracker

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    I would no more keep riding a bike that had a repetitive wobble then play with a 6 ft rattlesnake,Your lucky you werent killed.
    Common sense can be helpful,Im glad you found the cause of the wobble.
    #9
  10. StephenB

    StephenB G(/)S ... what else!

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    I am really glad, you're ok. It could have been worse. Sorry, you had to learn your lesson the hard way.
    #10
  11. elmoreman

    elmoreman takin' a break, boss

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    These thoughts are the crux of the matter. Annoying problems (even safety issues) almost always seem to go from

    "it happens when I do this"

    to

    "now it happens when I do this"

    I had a leaky neutral switch indicator, and asked (I believe on this board) if it was worth fixing before I went on a weeklong trip. Someone said to me, "why would you leave on a trip with a known problem?" and that logic has stuck with me. Having two bikes makes it an easier decision sometimes, although one of them is not up for a weekend trip.

    Regardless, again, I'm glad you're OK. :thumb And kudos for going ATGATT. That is something that has stuck with me now regardless, even last summer when it was 110 degrees in mexico.
    #11
  12. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Glad you came through relatively unscathed! And let us know what fixes the wobble.

    I've had them before, and even though there are quite a few things that can cause wobbles, in both cases it came down to the front tire. Normal suspects are: swingarm and steering head bearings, wheels and wheel bearings, shocks and uneven loading of luggage. Rear shock settings affect steering geometry. And then there's Duane Ausherman's story about curing /5s of the wobbles - that's an interesting read.

    The front tire on my 90/6 when I first got it didn't look too bad, but I'd get the wobbles at 30-35 mph, accelerating or decelerating. At first it scared the crap out of me, but after several times I got nonchalant about it. Once the front tire was replaced it never happened again.

    My R100RS did it once as I accelerated out of a parking lot. Low speed - 20mph or so. Good thing it was a Sunday and the streets were empty because I had no control! Those bars were really violently whipping back and forth. I tried everything - pushing on both grips, pulling, weighting the pegs, gently accelerating, and finally the only thing I could do was gently decelerate and pull over. An inspection found nothing wrong, but the tire was looking a bit worn (though not into the wear bars) on the left side. A new tire and it never happened again.

    I recall hearing that the ribbed Continental tires that came on the 70s beemers was responsible for wobbles and that's possibly true. From my experience, the front tire contributes (or detracts) quite a bit to front end stability. And check out Duane's article on handling the wobbles - an interesting read!
    #12
  13. Gimmeslack

    Gimmeslack furthur

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    +1 on ALL of it including GLAD YOU'RE OK :yikes

    And do be sure to report back when you think you've found the cause. :deal
    #13
  14. StumpThumper

    StumpThumper Adventurer

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    Most speed wobbles are rider induced by holding onto the the bars too tightly. If your bike has a wobble at the same speed every time you have a mechanical problem.
    Loose bearing - wheel, steering head, swingarm.
    Loose spokes.
    Loose axle.
    Low tire pressure.
    Fork mounted windshield causing oscillation.


    Sitting still on the bike snatch the handlebars back and forth as if performing a quick swerve and then forcefully stop the handlebars back in the center position. The bike should feel solid. If it feels like it's flopping around you have something loose. Have someone watch each part of the suspension/wheel as you do the swerve manuver to locate what is loose.
    Hope this helps. Nothing worse than a bike with a hinge in the middle.
    #14
  15. nowhereman

    nowhereman I'm lost -don't follow me

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    I had a problem with my bike and speed wobble / near tank slappers. It'd start around 80 mph and only with TKC80 tires. Once I changed the tires to tourances, it never happened again at that speed.

    I did have another occasion with a wobble, that was with my baggage fully loaded for the first time. I didn't change the shock preload for the added weight and set off down the road. I hit around 60 mph and could feel the front end start to get a little oscillation, above 60 it just got worse. I pulled over and checked tire pressure, spokes, etc. and realized I hadn't set the shock up - 3 or 4 spins on the preload to my calibrated eyeball and I was in good shape.

    Glad to hear you lived through it tho. It's some scary stuff for sure.
    #15