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High Speed Wobble

  1. #1
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    High Speed Wobble


    All right guys, I have a question that has been making me nervous for a while. I've heard people mention this "high speed wobble" where the bike sways back and forth and goes out of control, but i saw a video online of some riders in these wobbles and it scared the shit out of me. I wanted to know what happens to cause this situation, and of course how to avoid it. Also, is there any way to correct one once it starts?


    Thanks,


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  2. #2
    I kick hippies...and Kham Nikon's Avatar
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    Re: High Speed Wobble

    Originally posted by Boner
    All right guys, I have a question that has been making me nervous for a while. I've heard people mention this "high speed wobble" where the bike sways back and forth and goes out of control, but i saw a video online of some riders in these wobbles and it scared the shit out of me. I wanted to know what happens to cause this situation, and of course how to avoid it. Also, is there any way to correct one once it starts?


    Thanks,

    it's called a tankslapper. I am not an expert by any means but Suf did a little thing about it a while back.

    THIS is one thread Suf started about it...dont know if the vids still work but you can try them out.

    ok...well...after searching...I could have sworn that there was a thread started about the 'anatomy of a tankslapper' that was a little more involved than the above thread but I can't find it. Anyway. There is some info there and I am sure that there will be a lot of posting about this....

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  3. #3
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    Re: High Speed Wobble

    Originally posted by Boner
    Also, is there any way to correct one once it starts?

    Relax your grip on the bars and pray like you've never prayed before. Better than 50% chance of getting out of it.


    Very basic description. Peter Kates can probably offer a better explanation:

    A tank slapper is when the front wheel is gyroscopically affected by something. Picture a wheel spinning on an axle, fast. It takes a lot of force to make that wheel deflect on the horizontal plane. As you ride down a straight road, maybe a pothole or something forces the front wheel off the straight course for a split second. Gyroscopic force tries to correct the deflection and will automatically deflect the wheel back PAST the straight course, sometimes further past the straight course than the original deflection. This sets up another correction in the other direction and the reactions continue until the handlebars are forced rapidly side to side against the frame stops. Any input from the rider (gripping the bars tight or fighting the motion) can have adverse effects and cause the REAR end of the bike to start to absorb some of the energy being generated in the front end causing the back wheel to start to come around from side to side just like the front end, then you are all done.

    As the tank slapper starts, if you lessen your grip on the bars and let the bike slow down and try to let the front end do it's thing, it will sometimes just settle down (as the gyroscopic effect is lessened by the bike slowing down, energy is dispersed to the rest of the bike frame and the road and the wheel deflects less and less to each side until it straightens out again).

    Bear in mind that most tank slappers last about a second or two. The bike is actually quite stable during a tank slapper IF you don't try to fight it (picture a BMX rider spinning the front wheel around the horizontal plane as he rides along, a very common BMX trick) because the contact patch of a front wheel is relatively small.

    Hope that explains it in VERY general terms. I'm no expert but I THINK I have got that somewhat right. Feel free to correct any mistakes I made.

    derek

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  4. #4
    I kick hippies...and Kham Nikon's Avatar
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    High Speed Wobble

    you act like you actually know a thing or two about bikes....

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  5. #5
    Just Registered beet's Avatar
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    he's a good guessen

    Originally posted by Nikon
    you act like you actually know a thing or two about bikes....




















    GIT WANKER

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  6. #6
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    Re: he's a good guessen

    Originally posted by beet
    GIT WANKER
    I'll kick you in da nutz bastige......

    Just for Beetster

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  7. #7
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    High Speed Wobble

    I had a tankslapper once and next day the scotts damper was on.what a difference.

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  8. #8
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    High Speed Wobble

    People often confuse tank-slapper with headshake.

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    2003 Yamaha R6
    1999 Yamaha YZ400



  9. #9
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    High Speed Wobble

    So what is a headshake?

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  10. #10
    Lifer Suf Daddy's Avatar
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    Tankslapper

    One of those things you hope won't happen.

    This video avitar isn't the one I was looking for, but its simialr to the vid I've seen where the guy tankslapps immediately after touching the ground again.



    Change speed is the way out, some accelerate, some brake, some hold on.

    Which ever you pull off......works for you.
    -Suf Daddy

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    Suf Daddy.



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