Harley Speed Wobble, Tank Slap, also known as the Death Wobble

Discussion in 'Touring Models' started by BaZa, Sep 7, 2010.

  1. BaZa

    BaZa Member

    Harley Speed Wobble, Tank Slap, also known as the Death Wobble

    With reference to the tragic loss of one of our club members here in the UK and very close friend to me, Chris Jonas on May 27th this year, here is a message from his brother Gary asking for any information if you have experienced any of the symptoms of a 'Tank Slap' etc.

    Please email Gary if you have had this experience.

    Thank-you in anticipation.

    This is the scene............

    crash scene 2.jpg
    Last edited by a moderator: Sep 17, 2010
  2. Tom-T-Bone

    Tom-T-Bone Member

    Heard about a similar accident last year....witnesses said his bike went into a "wobble" and that was that......unfortunate loss of life...he was riding an Ultra Classic...not sure what year....I hope you get the answers you're looking for........PS...sorry for your loss.
  3. Fossil

    Fossil Active Member

    Sorry for your loss. I have owned a few Harleys and have never experienced or see a Harley speed wobble. The few bikes that I have seen the aftermath of had a lack of adjustment or simply no maintenence by the rider or the dealer. Some of your checkups are supposed to have the bearings relubed and adjusted. Some maintenance is for adjustment. It takes time on a dresser to pull all that stuff off and not scratch any of it just to adjust the bearings in the neck of the frame. It is a simple process but I have known bikes that have never ever had it done. This isn't to say your brother was this way. If you have his bike and the forks are still whole read your manual and see if the bearings are loose. Pull the bearings out to see if there is any thing unusual. Check the race too. Good luck.
  4. FLHTK2010

    FLHTK2010 Member

    Very sorry to hear of the accident.
    I personally experienced high-speed-wobble on my 1973 Triumph Bonneville many years ago in 1975. Obviously I survived, but I did go down on the highway at about 65 MPH. Luckily I just skidded along and did not hit anything, and nothing hit me. Tore off a lot of my skin though.
    My repair shop told me that the front wheel was "out of round". This was in the old days of spoke wheels. I would not own a bike with spoke wheels because of that accident. God that hurt.
    The bike had wobbled on me before, but had straightened out on its own. This day it didn't straighten out. I'd been told that when this happens, to give it more throttle to take the weight off the front wheel. I tried this, and it didn't get worse, but it didn't improve either. As soon as I let off the gas, it went wild. The front wheel went left and right so violently that there was no way to hang onto it. The bike went down and I stayed on it for quite a skid. Looking down I could see sparks flying and remember thinking , oh man, this is really going to hurt. I came off the bike and that is when I got a strong dose of road rash.
    I quit riding for many many years.
    Moral of the story is that this is not a Harley Problem.
    Best wishes to you.

    I should have included:
    "I had just entered the highway via a long entry ramp, running through the gears to the top gear. Travelling on a brand new highway, no crosswind, going in a straight line. I had installed a windshield just prior to that ride, but don't know if it had any affect."

    Last edited by a moderator: Sep 17, 2010

    NEWHD74FAN Experienced Member Retired Moderators

    Actually in this case the windshield probably made the problem much worse if it was a handlebar mount one. Large windsail, out of round front wheel, questionable tire condition and steering head bearing/preload...certainly a lot of factors. Adding accessories on the front end should not be taken lightly and road worthiness tested prior to for static baseline, and after installation...long and hard at different speeds and such.
  6. catfishon

    catfishon Member

    not had this happen on my harley but i did have a 79 goldwing with full fairing that would start to wobble anytime i went fast and let off the throttle to fast. im pretty sure this was all due to the fairing and as long as i gave it more throttle it would stop . i would then back it off slow and it was ok .
    but it would always scare the (EDIT) out of me.
    sorry to hear of your loss.

    Please read this...
    A Friendly Reminder - Harley Davidson Community
    Last edited by a moderator: Sep 27, 2010
  7. sprinklerfitter669

    sprinklerfitter669 Junior Member

    Sorry for your loss.
    Have not had this happen to me, but i will be doing more research.
  8. Patriot

    Patriot New Member

    I had the "Death rattle or Harley high speed wobble" happened to me for the 1st time just the other day! Hope it never happens again!!! Heres the bike & scenero:
    94 Road King newer tires, Windshild, hardbags.
    Riding about 70 mph on a highway turn not sure it had embankment. Halfway through turn, the front end started shaking & shimmying and was difficult to keep in the turn. Lucky the highway had middle lane and no oncomming traffic. I regained control in the middle of the oncomming traffic lane by applying gradually both brakes, keeping it straight and leaning hard to the right without turning the handlebars because turning seemed to make the wobble much worse. I finally regained control about at the 45 mph I think. Carefull drove home through many more turns very slowly with no further incidents...thank GOD!

    I'm here because I was researching what happened...and looking for advise & to share;' thios is my first time on this site. So far going to check out the neack bearing & repack it & closely check out the fork oil, measure & change it. Any other advise?
  9. sprinklerfitter669

    sprinklerfitter669 Junior Member

    Welcome to the Forum, and glad you made it through, to share your story. :s
  10. Hoople

    Hoople Account Removed

    Sounds like rear wheel steering caused by rear wheel alignment or engine/transmission rubber mounts being worn & too soft. Perfect rear wheel alignment along with correct axle shims so NO wheel offset exists between front and rear. That is a Must. Perfect rear wheel alignment in relationship to the front wheel is a Must (florescent light tube trick). Add a True-Trac 3 point stabilizer and I would bet you can say good-by to that wobble happening again.

    These are the "big hitters" I would absolutely check. There are also a bunch of other secondary reasons how/why that can happen.