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

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

  1. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    I have heard that these help:Google
  2. NiteOwl

    NiteOwl Member

    I have had it. Its scarry. Its a design problem. The solution is to do dome research on a good stabilizer. It adds another connection point for the Engine and Trans. HD will even sell you and install one. Do your homework. Buy a good one and install it as per instructions. This is a very well known thing. It even happens with the new frames of 2009 and up.
  3. Had this happen to me twice. First time was a front tire that went flat. Lucky for me, I was only going about 35mph. I did have spokes on that bike, and the rust on the inside of the rim rubbed the tube and put a hole in it...The second time, on a 2011 Wide Glide. I was probably doing about 70. It was a slight wobble, I backed off on the speed. The wobble went away. Pulled over and checked air pressure and just did a visual around the bike. I thought it to be the road, it is not that uncommon in La. to have a lot of small bumps in a row, on asphalt. Once back on the bike, I slowly went back to 70 and it occurred again. Two days later, I put a set of H.D. mag wheels. It never happed again. Sorry for your loss. I spend a lot of my pay check to prevent things like this happening. I'm not saying it was neglect to the bike..Sorry for your loss
  4. mrglide

    mrglide Member

    A good friend was almost killed recently because of the high speed wobble. He spent weeks in a hospital and a care center before being released.

    He was riding on an open, straight road and just lost it. He admits he was going at least 95 mph, if not more. I do not think it should happen at any speed, but there is a reason it is often called 'high speed wobble".

    The only reason he is alive today is because of his helmet.
  5. screwylouie

    screwylouie Active Member

    Never had it happen to me but my old V Max had a real reputation for tank slappers. The VMOA forum had a fix that involved the steering head bearing adjustment. I think it's pretty common, that's why lots of sport bikes have steering dampers. There's some moto gp videos of high speed get offs where the bars go lock to lock so fast it's unbelievable!

    I am very sorry for your loss!!
  6. wfmacii

    wfmacii Member

    This is a great thread. It demonstrates the importance of bike maintenance. Especially in adjusting and greasing the neck bearings, spoke torque on laced rims, tire pressure etc. It definitely got my attention. Thanks to everyone for the thoughtful input.
  7. wills

    wills New Member

    I've had two such tank slapper incidents. The first was on a Gen1 Vmax at 'high' speed. It was so violent and extreme wobble that after I escaped from that without incident, I sold the bike. This was in '91, going thru the hills of San Clemente while following some new generation sport bikes.

    Years later a second incident was a bit of a revelation. It was on a 1200 Z-Rex and I was just doing what I thought was a normal 'spirited' acceleration, but I had my weight shifted more toward the rear and I was a bit more upright with arms outstretched further than I normally ride & I found that just this amount of unloading of the front fork was enough to initiate a strong wobble. I backed-off enough to get more of my weight toward the front and it immediately stopped. From then on, whenever the front started feeling too light, I just bend the torso forward and it's enough to stop any wobble. This seems to work on any bike I'm on.
  8. dbmg

    dbmg Guest

    Glad you were able to get out of these incidents with out any more problem. Usually the Electra Glides starts this condition if everything is right, speed, cornering force, weight shifted etc. when coming out of a long high speed corner. It is a condition that normally just starts on its own. You are usually pushing bike past its cornering capabilities.
  9. mlemay

    mlemay Member

    I experienced this a couple times on my current bike when I pushed it a little too hard in corners. I went with Sta-Bo bushings. This helped a lot, but I still feel a little wobble when I push the bike too hard in corners. I plan on putting an additional stabilizer on it this winter just to be over cautious. Sorry to hear about your loss.
  10. tensman

    tensman Member

    My 08 Ultra SE has an oversize windshield; I've never done any maintenance to the steering bearings or the shocks. I do keep tire pressure up (40 psi front, 42 rear). Bike bought new now has 111,000+ miles. I've never had a steering wobble, for what it's worth. I do not have any added stabilizers, etc.