Tankslappers

[Jackyboy]

Heya was riding back from work today (45 miles each way down the A21) and my handlebars started to shake violently. I've heard about 'tankslappers' and was wondering if anyone ha any tips on avoiding them as it scared the pants off me!

[Kickstart]

Hi

That wasn't a tank slapper.

To avoid them keep everything in decent condition. Tyre pressures, steering head bearings, wheel bearings, suspension, etc.

All the best

Keith
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[Misc]

Going fast over crap road surfaces causes the bars to shake a bit,

[AcIdBuRnZ]

Mate - wait until you get on a big sportsbike then you'll see what it feels like when a bike shakes the bars or wobbles/catches air over jumps.... a lot more scary than that for the first time
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Past: Honda NSR125R >> Kawasaki ER-5a2 >> Kawasaki ZZR-600e1 >> Suzuki GSXR-750Y >> Honda VTR 1000 Firestorm
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[Annabella]

As Keith said, keep tyre pressure correct and the bike well maintained can help to avoid them.

Tank slappers usually occur when the front end of the bikes goes light, either through hitting a bump in the road or it lifting from power. Either way this can trigger an harmonic movement in the bars (from side to side), because it is harmonic it will get increasingly worse.
The best way to stop it is to go against all natural reactions and relax, let go of the bars and allow the harmonic to die away naturally.

And yes, big bike or little bike, it's bloody scary.
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[Jackyboy]

thanking you for the advice... the front tyre appears to have a slow puncture. i'm getting to scrap the little bugger next week - got a new bike on order

[Sephiroth]

I always thought you should accelerate out of them?

[AcIdBuRnZ]

[Dark]

[paulyzf600]

I heard that some very violent tank slappers you can't hold on at all as they shake at such a speed and with such Violence. Can't remember the speed at which they slap but it's un real the amount of times in a few seconds they can go each way.
I was also told to relax and keep power on and accelerate out of them.
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Yamaha YZF600 Thundercat

[Jackyboy]

What's the possibility of getting one on a 125? I'm built like a stick and I probably won't be able to hold the throttle on! should i consider getting a steering damper?
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[Kickstart]

[Jackyboy]

Sounds like i should jump and hope i hit something soft then? I think I'll just try to avoid them!
____________________
Insurance Beehatch Supremo- Direct any grumbles about repudiated claims my way
Yamaha SR125 - Scrapped 13/06/2006. Hyosung GT125R - Totalled 18/11/2006.
Honda VFR400R NC30 - Totalled 09/02/2007. CBR600F - currently in 1 piece...

[0ddball]

There's not much danger of it on a 125 unless the bike has a fault e.g worn headrace bearings or you are trying wheelies.

[veeeffarr]

[Jackyboy]

[Jebus]

if you want to know just how much damage harmonc resoance can cause, think of this. have you seen the pictures of the suspension bridges that in a fairly light wind start to sway then go nuts and fall apart, they got killed by harmonic resonace cause by the wind flowing over the struture.
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2nd time around CBT: 8/9/11
125 Varadero

[Jackyboy]

[Jebus]

lol sorry, but a real tankslapper dont really happen unless you are really pushing on a scary bike, like a tls1000 you can still ride fast without risting one, just dont go nuts over dodgy tarmac
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2nd time around CBT: 8/9/11
125 Varadero

[Clanger]

I had a nasty tank slapper experience a few years ago, I was heading up to a roundabout, skidded on diesel and off it went, I fought it, held on like hell, had my feet down (I know I know!) but it worked out okay, and eventually managed to stop without coming a cropper. I flopped down on the bike and a fella from a car ran over to see if I was okay and said that was a helluva save, I turned round to see all the traffic in the dual carriageway had stopped to let me get a handle on the situation.

I dont think I'd ever lost so much fluid from sweat in my entire life.

It was a hellish experience, and I couldnt accelerate because I had to slow down....
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[Jebus]

that dont sound like much fun, at least some car drivers will be nice to you. Its not an experience i want to experience but its going to happen one day.
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2nd time around CBT: 8/9/11
125 Varadero

[damnas]

So, given all of that, what are the chances of a tankslapper happening on a 600, lets say a Hornet, or a Bandit?

Pushing it maybe a bit (a lot) but no wheelies / stoppies, and a fair bit or motorway riding...
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[Stoo]

[suzi_bandit]

I thought tankslappers happen when you're pushing it really hard and the road surface is bumpy and uneven?

There's references to tankslappers when sliding, is it the same thing?

I did step a front tyre quite badly last winter (my fault, tyre was underpressure) and because of that the bars would shake violently if I loosed go of them
Entirely different thing though, isn't it?
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[Stoo]

Check this

https://www.joe250.com/motorcycles/ride/tankslapper.htm

This explains WHAT happens during a tank slapper. It's basically the front wheel being out of alignment with the direction of motion when it touches back on the ground (or regains traction in the event of a diesel slip). You end up with a gyroscopic motion which will either attenuate or chuck you off!