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What to do during tankslapper

Discussion in 'New Riders and Riding Tips' started by Ljiljan, Nov 18, 2009.

  1. Had a big one today, as described here. My question is what is the best way to handle it? I found the SR to be hold on as tight as humanly possible, but knowing that SR's are usually perilous on a bike, I'm wondering if it is the same in this case or if holding on for dear life is acceptable.

    In the case of it being dangerous, anyone got tips of how to safely practise having a tankslapper?

  2. stay on the gas and ride it out keep your body relaxed don't tense up, like we all normally do when we have a OH **** MOMENT, though it's easier said then done imo 8-[

    otherwise a steering damper helps too
  3. Stay on the gas is the accepted theory,
    I have had one tank slapper which was on a corrugated road. So the slapper was induced by the road surface and there was no way that was about to change in a hurry.
    I actually rolled off just a little. Not dumped the power ,not any where near the brakes, just took the sting out of the acceleration. This settled the bike, and once I had it lined up I dumped the power off.
  4. Attempting to hold it straight will generally increase the severity as your inputs will match the frequency of the 'slapper and will, almost certainly, be perfectly in phase with it so you get a positive feedback loop.

    Relaxing is good, but bloody difficult under the circumstances. You now have the advantage that you've experienced one and didn't die so you're less likely to panic next time.
  5. Pat, I am not sure if having had one will make the next one easier to handle…
    They really freak you out a tad
  6. Here's a case where theory and practice are miles apart. It's near impossible to stay on the gas if you have a fully developed lock to lock tank wildly swinging slapper. People say take the load off the front wheel as it reduces the overcorrection forces that the bike geometry has induced.

    Harmonic tank slappers are violent and are a "feature" of typical bike geometry. The best thing to do is hold on tight and dampen out the vibration - which is directly at odds with the advice in this thread.

    I had a ripper once on the 250. I was exiting a corner and hit a pot hole filled with blue metal. I was a passenger of physics from that moment while the slapper sorted itself out. My hand was off the throttle and the bike in a lowish gear so it decelerated quickly. That took the steam out of the forces and the slapper sorted out BEFORE it ghost rid itself into the drainage ditch.

    As is my usual want, I've gone to msgroups and looky looky, there's a whole article on the topic: http://www.msgroup.org/Tip.aspx?Num=190 and in a nutshell, it says, hold on tight and try to slow down.
  7. You might want to look at the suspension setup of the bike as well, especially the front end.
  8. my last(and only big one) i actually had the bar's pulled out of my grip. I was only loosely on the bars as the dirt road was shocking(worse than i was told to expect... way worse). By the time i had re taken hold of the bars,, it was over, but I believe if i was hard on the bars when it happened I would of been in the bushes for sure.
  9. My Uncle is an ex bike copper. They had extensive training where they had to try to induce tank slappers and recover. ( :shock: )

    They were told to just take it gently and try to get as much of their body weight over the front wheel as possible to get it to settle back down. I tried it once (completely by accident) and it seemed to work beautifully.

    I have no idea why, what, or how it works. Perhaps somebody else here can answer that?
  10. Interesting. The front brake would be the best way to put lots of weight on the front wheel, which goes against the 'stay on the gas' advice.
  11. So you are considering putting the front brake on when the wheel is knocking from full lock to full lock???
    That is basically saying put me down I want to tumble down the road.
    Resistance on the front wheel is the last thing you want.
    Taking the load off the rear and gently applying it to the front by rolling off gently is one thing but applying the front brake is Insane!
  12. I normally open and close my sphincter at the same frequency as the tank slap.

    It doesn't help though.
  13. mmm...well...it's my belief that if you've developed a full-blown tank slapper (lock to lock)...then it's over...there is little you can do accept ride it out and hope the bike settles itself. By the time you've thought about it, it's either over or you're sliding down the road...
    You can give the bike it's best chance to settle itself down if you go inert on the bike, and neutral on the throttle.

    For the more average front-end wobbles that most of us experience, I'm not convinced that extra power is likely to do anything much, since that's what has caused all of my "handle-bar shakes", and so I unwind the power a little to let it settle down again.
    Certainly though, I personally would not slam the throttle shut, and no way should you hit the brakes...and I have always tried to fight it with strong but neutral arm control (not trying to counter force against the oscillations - but resist them equally on both sides, with no arm movement). It might also be beneficial to take your weight on your legs rather than just sit there full weight on your bum, where your body weight can add to the problem.

    That's just what I do..

  14. Always enjoy reading your posts Raven.
    When you mention about wind the power down, I take it that it would be best to stay in the same gear as well. Is this correct?
  15. Yes Geeth...forget gears...no time...just ease off the power.

    I say that, since any head-shakes I get into are usually under hard acceleration, so I just ease it off a bit...still on the power, just not as much..
  16. cheers guys, rob will have a look at that link.
    raven: thats what I was doing, not trying to counteract, just trying to hold it still. It was a full blown thing, the real deal I said in the link in OP that it went for a solid 2 seconds minimum, hands banging against the tank. Not some piss weak little wobble, i've had those before.

    Its a hyo 250, so a steering damper is wishful thinking, and im in the process of selling so not going to bother with getting the suspension properly done.
  17. Wouldn't putting your weight over the front also cause the forks to sag, your steering angle to sharpen and cause more of a slapping sensation?

    Thinking out loud here. That's what used to cause my bad tank slap - shitty, soft front end.
  18. I would'nt say the smaller head shakes are "pissweak", it depends on the circumstances...Hard out of a corner at 18 - hit a bump or rough patch and get a solid head-shake can be a bit of an eye-popper. :)
  19. lilley I also ride the hyo 250, easing off the power and letting your arms go loose rather than stiff works for the little-uns. I do a bit of dirt now and again... Though at those times I wish I had the TTR250 in the garage here.
  20. i had one, and i can't remember what i did, but the bike settled.. was doing 140 down a dodgy back road and a 4wd passed me at the same time, so i think it was a combo of , speed, hyosung, 4wd, dodgy road.