Tank slapper, what is the cause?

[dudders7]

G'day all,
Went out on my ZX6-R today for a long ride through the twisty's at the National park. Incredible fast pace riding, beautiful bends, then a CBR1000 comes along and we have a bit of race through the twisties then we hit a straight and both of us give it everything the bikes have get upto about 240KPH and I get a major tank slapper, wrists felt like someone was trying to break them I somehow kept control of the bike when the tank slapper stopped. Slowed down and continued on my ride, the tank slapper was so violent both mirrors were flung backwards and they are pretty stiff to move. So what is the cause of this? How would I go about preventing it?
Cheers
check this video its similar to what happened.
https://www.youtube.com/watch?v=SAnjjHKclZs&feature=youtu.be&t=55s
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Riding in the sun in Australia on a 04 Worked ZX10R along with a fleet of other crazy toys

[Hyaon]

Did you wheelie? putting it down again with a slower front tire than rear can be a bugger. Especially if put the front wheel at an odd angle.
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Mod2 Passed 30/03/2011!
CBF125>GSF650 Bandit K8>B-King 2008+R1 2002

[Llama-Farmer]

That would shit me up. How did you recover, just roll off the gas and let it sort itself out?

[Snorty]

You probably hit a bump whilst accelerating, then your front end came down wonky.

Need a steering damper to prevent bad tank slappers. I had a small one the other day whilst caning it up a bumpy road.

Some say to accelerate, which will take the weight off the front end of the bike and make the steering light again, though when it happens I don't think you would be thinking anything other than "oh shit!".
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Current: Yamaha FZ1 '07 | GSXR 750 SRAD

Past: CB125TDC | TZR125 | GPZ500 | CBR600F3 | ZX9-R | GSXR1000 K4

[Easter Bunny]

at some point the front wheels is airbourne through speed or a bump/dip and hits the ground at a slower rate and possible out of line, causing a wobble which just gets worse if you have excessive speed.
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The light at the end of the tunnel is an oncoming train!

[Llama-Farmer]

[dudders7]

I had just crossed the line as we overtook a car and I think I hit the cats eye as I crossed back into my lane. Was pretty scary but just held on tight and wrestled with the handlebars, pretty sure I accelerated an instinct made me not touch the brakes, I pretty much wrote myself off in my head and just hoped for the best. I have no idea how I kept in a relatively straight line, was very lucky!!

Should I get a good steering damper? Also I have quite badly leaking front forks which still feel ok but it is booked into the suspension company to have them rebuilt and set up properly. They rebuilt my rear suspension last week and its been like riding a new bike it feels like its on rails until the tank slapper... Ill avoid hitting cats eyes at high speeds from now on.
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Riding in the sun in Australia on a 04 Worked ZX10R along with a fleet of other crazy toys

[smegballs]

Disclaimer: Never had a tankslapper myself.

I remember reading once, that the best thing to do is NOT fight the bars and instead try to relax your grip on them. Idea being that the harder you grip the bars the greater the positive feedback from the chassis to the front end. By relaxing your grip you let the bike damp out the oscillation as it is designed to do.

[dudders7]

I think if I had relaxed my grip and not having a steering damper the tank slapper would of continued and having a cliff with a very long drop on one side and trees on the other instinct says hold on like fuck! And I managed to recover it did a couple more bends considerably slower and stopped for a fag. Was a bit of a shock and you can't see anything when your being shaken like that. Not recommended as something to try!
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Riding in the sun in Australia on a 04 Worked ZX10R along with a fleet of other crazy toys

[MaybeGuy]

why do you always end up almost crashing?
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[fox]

I've never had a tank slapper thank god. From what I've read wrestling with the bars is probably the worst thing you can do, as the wobble can transfer to the rest of the bike.
The best bet is to accelerate hard to get the front wheel off the ground. Although I would imagine you are very much the passenger once it starts.
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Sold: 2003 satin black Yamaha R6
Current rides: 2006 blue Triumph Sprint ST 1050, 2003 Yamaha WR450F

[binge]

I cant say I've ever had a tank slapper (A proper one), and I've owned 2 of the most prone bikes that suffer from them.
Granted they both had Ohlins dampers fitted, but I always had them set to minimum.

I've had the bikes 'shake their head' a bit before, but only when accelerating hard out of a corner, and the front wheel has a chance to break away from the road.
When it's happened, I've always just maintained a progressively steady throttle, and ridden through it.

[DottyDuck]

shhiiiitttt! that must have been scary! i think i would of probably pulled over for a minute to get myself together! lol glad you managed to keep the bike up
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CBT- 2012 Theory- 18/12/13 Mod 1- 07/01/14 Mod 2- 15/01/14
Old Bike: Zontes Panther 125cc - wrote off Current Bike: Kawasaki ZR7

[Lyam]

had a few now, second time i kept the accelerator pinned and it dissapeard then i went into 3rd and as it climbed up the revs it happened again, i just came off a tiny bit and all was well.

[1cyl]

Interesting reads. Glad to hear you made it through ok OP.

Ive never had more than a few slight speed wobbles over bridge tops and when I've replanted the front a fraction askew.
It does sound a terrifying experience. And this has resulted in me reading and re reading the description of a tasty looking GPR4 dampener for about 300 quid from the states. Yet to buy for fear of fitting it, only to ride with it once....find it to strange....Then turn it down and leave it on minimum till I get "slapped".

Yet to find an sm rider whos had one and told me its worth it.
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Chase my Witch up, Catch my Snitch up.
The SMC | The Pit | Stable

[TUG]

I've had a few slappers in my time, and they only way to get out of it is to power out of it, the last one I had was a wheelie I landed, the wheel was pointing right so you can imagine how badly that shook, i had no power to get out of it and I got knocked out.

I had a similair experience on my VTR, I had no gear on, just a helmet and gloves, yep fucking stupid, landed shook its head like a bastard but I ripped the throttle back and it powered out. My cafe CG is getting a fucking damper!
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Haz ER-5, innit!

[dudders7]

Thanks for the replies guy's, it was a more surreal experience than anything else. I carried on riding for a couple more miles before the shakes got me and I had to stop for a ciggy and clear my mind in readiness for the rest of the ride.

It hurt like fuck the brute force on your wrists, I am pretty sure it was probably twice as violent as the video.

Bought a GOPRO 3 today so I will get that mounted, before my next ride just incase! Got to say pretty freaked out about going that fast again, realizing how such a tiny thing in the road could have easily killed me. I am one lucky SOB...

Definitely getting a steering damper fitted. I don't think its done anything to my confidence as I rode back through the twisties at a slightly higher speed on the way back although I would not go above 150 or 160KPH on the straights!

All in all a lesson learnt, high speed and cats eyes do not mix!

Can't stop thinking how lucky I was to pull through that!

Ride safe guys n gals
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Riding in the sun in Australia on a 04 Worked ZX10R along with a fleet of other crazy toys

[TUG]

[thepuma]

Riding at 140mph on a public road......clever
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YBR125 (SOLD) - CBR250R(SOLD) - CBR650F(SOLD) Current - Street Triple
765 RS

[Irn-Bru]

[Kradmelder]

I had one on a gravelly road at 80, not the speed you tar riders do. I was riding in the cage tracks between ridges of coarse gravelly sand, trying to catch up to a mate. I tried to change lines nd hit a ridge of loose stuff at a shallow angle, while thinking this is stupid.

I went over it then the bars started a head shake. The front wheel lost traction when lifting. Luckily the wheel travel on a ktm is very limited. I applied a bit of throttle and she recovered. It was quite quick. If I had braked or released throttle guess I would have high sided if the front wheel bit into the loose stuff
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2011 KTM 990 Dakar
2009 BMW 1200 GS

[Acemastr]

Had this recently, I had buggered my suspension settings up so much that it was unstable.

Set the suspension back to standard and haven't had a slap since, although it is always on my mind now, the one i had was crazy
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2017 KTM 350 XC-F - 2014 Yamaha R6 - 2005 Yamaha YZ125
2016 Toyota Tacoma Limited

[Dean-J]

[haroman666]

[dudders7]

The Gopro is a toy that I wanted to get, the steering damper is being fitted friday afternoon prior to another mental weekend
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Riding in the sun in Australia on a 04 Worked ZX10R along with a fleet of other crazy toys