How do you stop/prevent a tank-slapper?

Papaya9

Registered
I just saw a video of a isle-of-man racer stuck in a tank slapping incident. What do you do in that circumstance? Thanks
 
Get a good steering damper before it happens.

Technically, all you can do is stay on the throttle and hope the harmonics reduce. But, that won't do you much good coming up on a corner. Letting off on the throttle will make it worse, simple physics.
 
I've seen that video too. Most peoples reaction is to throttle off > but the above guys are correct in my opinion.

Keep the throttle open> even lift the front wheel off the ground if you can, that will stop the tank slapper immediately.

Tank slappers are very rare on a busa as far as I know
 
BUY A BUSA...

FAILING THAT, GET THE FRONT OFF THE GROUND IF YOU HAVE TIME, BEFORE YOU GET EJECTED. I HAVE READ THAT THE KEY IS GETTING INTO THE THROTTLE, NOT ROLLING OFF.

I CAN TYPE IN ALL CAPS CAUSE I'M A TOOOOOL!
redcomprs2.gif
 
newbie question............ what is a tank slapper. I gather whatever it is.... its not good
 
That video you are refering to was a bad slapper. It was caused simply because his front wheel got a little airbourne as he went over the little hump and into a turn which caused the wheel to come down at an angle to the road. When the wheel hits the ground at a different angle than you are travelling the reaction is that it jerks back the oposite direction, and vice versa, and so on and so on and it gets worse usually and normally cannot be stopped unless you can re-lift the wheel as suggested above (get on the throttle HARD) and straighten it out. Otherwise kiss it goodbye my friend.

And yes the steering damper is meant to prevent this and any other sudden steering movement.
Busa's come with them.

Oh, the term tank slapper (for those that do not know) obviously comes from the fact that the bars appear to hit tha sides of the tank as the bars go back and forth and in the old days it sometimes dented the sides of the tank if it damaged the stops during, hence the term tank slapper.

God I hope it never happens to me.
 
Front end turbulence
crazy.gif
 !  When your frontend starts to get a bad shake of the wobbles >>>>usually happen when guyz are doing wheelies and the front tire stops spinn'n  before putting it down in addition to what the brotha said.
idea.gif
 
A busa will tank slap, too. I went down because of one once. The stock damper, while it helps, is really inadequate, especially since they always eventually fill with air and have such light weight fluid.

A tank slapper itself is a gyroscopic effect. Your front wheel is a gyroscope. For anyone that went through first year mechanics or anyone that has played with those little spin-up gyroscopes, you know that they are very stable when spinning. But when you suddenly jerk or twist it, it can start to wobble out of control. As the wheel slows it gets worse. It just helps to think about these things so if and when it ever does happen, you will hopefully react quick enough and know what to do to help save wrecking.

A few cases where slappers can occur include coming out of a high speed sweeper, bumps at extreme lean angles and high speeds, coming down from a wheelie and hitting the front brakes, coming down from a wheelie with the bars twisted and losing air on the front and touching down.

A slapper won't occur in all of these conditions, of course, in fact, one may find it difficult to initiate one even if they try. But given the right angle, right speed and right conditions, slapping can be very easy.

In short, a high quality steering damper is your only insurance against one. Again, the stock Suzuki dampers, while they help, really just don't cut it. The easiest and cheapest solution is to remove the damper and add some 30-60W oil to it (15W is stock). The better, but much more expensive, solution is to buy an Ohlins or similiar aftermarket damper. But that is really only if you are actually going to be riding or racing at extremes, or if you want a bit of wheelie insurance.

umnik.gif
thumbs-up.gif
 
A busa will tank slap, too. I went down because of one once. The stock damper, while it helps, is really inadequate, especially since they always eventually fill with air and have such light weight fluid.

A tank slapper itself is a gyroscopic effect. Your front wheel is a gyroscope. For anyone that went through first year mechanics or anyone that has played with those little spin-up gyroscopes, you know that they are very stable when spinning. But when you suddenly jerk or twist it, it can start to wobble out of control. As the wheel slows it gets worse. It just helps to think about these things so if and when it ever does happen, you will hopefully react quick enough and know what to do to help save wrecking.

A few cases where slappers can occur include coming out of a high speed sweeper, bumps at extreme lean angles and high speeds, coming down from a wheelie and hitting the front brakes, coming down from a wheelie with the bars twisted and losing air on the front and touching down.

A slapper won't occur in all of these conditions, of course, in fact, one may find it difficult to initiate one even if they try. But given the right angle, right speed and right conditions, slapping can be very easy.

In short, a high quality steering damper is your only insurance against one. Again, the stock Suzuki dampers, while they help, really just don't cut it. The easiest and cheapest solution is to remove the damper and add some 30-60W oil to it (15W is stock). The better, but much more expensive, solution is to buy an Ohlins or similiar aftermarket damper. But that is really only if you are actually going to be riding or racing at extremes, or if you want a bit of wheelie insurance.

umnik.gif
 
thumbs-up.gif
Hey Narc, Were talking Shock oil right? Not regular Motor oil.

Dumb question I know but I would be a prime candidate for increasing the weight of oil.
 
funny... I always thought a tank slapper was when your balls "slapped" the tank from landing a wheelie to hard. What is that called? 'Cause I have done it a couple of times and it ain't right!
 
Hey Narc, Were talking Shock oil right?  Not regular Motor oil.

Dumb question I know but I would be a prime candidate for increasing the weight of oil.
It does not have to be shock oil. You can use regular motor oil or even gear oil if you want.

When you remove it, move it back and forth. I will bet that it will be making squishing sounds, indicating a lot of air in the damper. Just open that little hole and drip oil as you move the rod. It takes a while to purge and fill.
 
AAAssjani.gif
  My busa hasnt done it to me yet and I have had it close to toped out.The 1100 I had along time ago did it at about 120 every time you got close to that speed. All you had to do was be ready for it stay on the throttle and lean way up on the tank. The first time it did it to me it scared the hell out me. I slamed on the brakes. I know wrong thing to do but all I wanted to do was slow down before I hit the pavement. Well I didnt so that can work also. I think if your busa does this you need to have it checked. Mine will give you just a hint of a shake sometimes at 150 mph?
 
Thanks for the input, guys. I think another way to stop a tank slapper is to grab the grab-rail behind you and put your feet on the handlebars and use your leg strength to break the harmonic. Of course, you have to be quite agile to do this.:rock:
 
funny...  I always thought a tank slapper was when your balls "slapped" the tank from landing a wheelie to hard.  What is that called?  'Cause I have done it a couple of times and it ain't right!
Squid Squasher <-- Seems appropriate for Oracle Whip
Orbs Smasher
Nut Slapper
Jewel Jammer
Nut Cracker
Suddenly, I don't feel so well.

down.gif
Damn glad to be a gal right now!
crazy.gif
 
Hey Narc, Were talking Shock oil right?  Not regular Motor oil.

Dumb question I know but I would be a prime candidate for increasing the weight of oil.
It does not have to be shock oil. You can use regular motor oil or even gear oil if you want.

When you remove it, move it back and forth. I will bet that it will be making squishing sounds, indicating a lot of air in the damper. Just open that little hole and drip oil as you move the rod. It takes a while to purge and fill.
Right On, Thanks a lot. I haven't had any headshake yet, usually my rear starts sliding around before the front get too light in the corners. I imagine some good sticky buns might change this.

Hooken, If you are getting any sort of head shake on your Busa at speed in a straight line you need to get things aligned. Nothing should shimmy, or shake, especially head shake/mini slapper...Bad JuJu... All I get when the peg is buried past 180 is some vibes and blured vision caused mostly by me trying to keep my chin on the gas tank and the winds desire to rip my head clean off. The Bike should be pretty rock solid at those speeds. Be carefull...
 
"Tank slappers"..not good..had it on my Ninja 900 once around 120....The thing that worked "that time" was pulling in the clutch....I was at high altitude,could not wheelie.....out of it...May work...good luck and be as safe as you can..PaceM...Man lock to lock many many times..glad it had a strong chassis....and sometimes..as hard as it may sound...
having a relaxed grip on the bars..may prevent that nasty headshake. caus' the bike will track true if one does not have a "death grip"....on the bars. Hmmm!
 
Back
Top