Tank Slapper

[riffer]

[Spot the n00b]

What's a tank slapper?

[/Spot the n00b]

Go here. There's a classic Isle of Mann tankslapper.

http://www.utahsba.com/html/gallery/video/video_2.html

[James Deuce]

[Spot the n00b]

What's a tank slapper?

[/Spot the n00b]

Here's a nice intellectual study on roading induced slappers.

http://www.ee.ic.ac.uk/CAP/Reports/2001/roadforcing.pdf

Here's a cute little Elmer Fudd cartoon

http://www.hawgeye.com/sniffy.htm

Basically it's when your bars oscillate at their natural frequncy, smashing your thumbs against the tank repeatedly; if you ride a sportsbike that is. I saw an HD rider with ape hangers wildly waving at me on the Southern motorway in Auckland once - until I realised that not many people wave violently with the entire front end of their bike.

[Motu]

The worst ones I've had have been on the beach in soft sand - these are huge steering stop to steering stop,the bike slaming side to side under you.There is no way to fight these,with the sand build up in front of the wheel if you locked your arms you'd be tossed off.Ridden them to a stop,but othertimes using the rear brake can help.

Riding an XS650 such things are an every ride occurance,but they involve the whole bike and it seems to be a lesurely experiance - in the corners it goes ''chink,chink,chink'' as the whole bike flaps around.At higher speeds it's bloody scary,feels like you are riding an origami bike.

The XLV750 has done some scary ones at speed - but I've found out why,so that helps.Seems I am getting air time or close to it,and countersteering at the same time in the corner - when we come down the front wheel is at an angle...so it straightens up with a mother of a wobble,so I don't blame the bike anymore.

[FROSTY:Me]

Had a good one on my mates TL1000s out hunua,just pulling past my mate doing about 240kph and she just went mental,no real reason.Kept her nailed (good old MX learning ) and it just got worse and worse,the whole bike was leaping from side to side (the rear was trying to come around )my mate who owned it was following and said he could see daylight under both wheels.....got to the point I knew it wasn't gonna come out of it and started looking for somewhere to crash it(I still had a bit of directional control.....)and decided to try to slow down a bit before I hit the ground ,and buttoned off(amazing how fast yer brain works in these situations isn't it?)......and it stopped Didn't ride it far after that
When I gave it back to my mate(after a quick change of daks)He told me 'yeh it does that,I just button off and it stops'(though he'd never had it happen that fast....)

Bugger--and noone there to video it for ya

[Posh Tourer :P]

My dad had one when he rode over a patch of farmer's dirt tracks on a sealed road at about 120. Didnt remember anything, concussed for 2 days, but apparently had a mean tank slapper start and throw him off the bike

[Holy Roller]

Only get them when on right hand corners that tighten as they go and if I'm 20 + kph over. First time gave one heck of a fright.
Coming from Tepuke to Rotovegas thought I was about to bin it. Like most of the other posts I somehow slowed down and rode through it. Must of given the oncoming cars a bit of a fright though. Now i am more careful leaning to the right.

[vifferman]

speedpro said:

I think those 16" front wheel Kawasakis were worse than the older bikes, except the triples, as they were either sweet or tank slapping to the stops with no warning.

I've never actually had a proper tankslapper, but the VF500 I used to own (with the 16" front wheel) started one when I hit some bumps near Picton doing about 160. Luckily, it stopped as quickly as it started, so by the time I registered what it was, it was over. I think if I'd had the Dunlop Arrowcrap I replaced the Metzeler front with, it would have been worse, as the fookin thing had headshake the whole time it was on, especially if you took one hand off the bars. Two hands? No way - it went mental.

The Firestorm tends to give a bit of a wiggle accelerating out of corners as the front end gets air, but it's never been a cause for concern, although a couple of times it's got a wee bit crossed up.

[Kwaka-Kid]

Umm, had a minor kinda one on the GS1000 in the wet going to work when i had the old tyres on.. it was weird, because 5th gear winding on power started to wheel spin and get a little out of control and i remember like just the whole bike shaking around and nearly falling off, or at least i thought i was nearly going to as it was like so scary! anyways just got one @ last pukekohe meet over the hill on the VFR400 and still dont understand exactly why and stuff but i did absolutly nothing... just carried on and it stopped, chances are it was like the most minor one you get but to me sitting on the bike i thought it was all over for sure! felt like i was just a rag doll waiting for it to get bigger and bigger - ask Keith Brock as i came around the outside of him shaking away and cut right across his line, thank god he had brakes because i sure as hell didnt have brains on what to do!

[Kickaha]

Crossing the Waiau river bridge on a XJ550 pulled out passed a car indicating 180kmh as it hit the 160kmh mark as I slowed it went into a violent shake,by the time I thought WTF it had already stopped.

[Big Dog]

Only ever had the one, funnily enough twelve hours after reading about it in a book from the library.

I was pitched in up north accellerating uphill when I hit a lump on the apex. Bugger!

On about the third oscillation i remembered that advice of the book picked a side (the side with the most road on it helps) and pulled on it as it started to slap to that side. This upsets the rythum and then treated it like any other vagueness at the frontengine brake and for Feck sake no front brake.

It worked for me. I only ever "tried" it the once, but I survived.

[Motu]

Sidecars alway have a shake somewhere in their speed range,you just make sure you don't go that speed.On one of mine I could take my hands off the bars - no wobble,give them a tap and she'd shake away forever,just a touch on the bars and it'd stop.

I've got some videos of mile flattrack - they come down the straight at 140mph,tucked down on the tank,one hand on the throttle,the other holding a fork leg - the bikes are shaking like crazy,you expect them to get spat off anytime,but no worries,they all do that.

[jimbo600]

Hey everyone,

I saw the famous footage that Le Mans reposted of the tank slapper.... That got me thinking, how many of you have had a tankslapper and what were the consequences....?? also were there instances where you rode it out, ie accelerating to lift the front wheel..? I hope like anything it wont happen to me, but im sure it will one day.......

Cheers everyonce

I had a belter in the UK on a FZR600. Shook so hard it wound off the headrace bearing locknut. What did I do? Shit my pants is what. Normal behaviour for the old FZR600 apparently though.

[Marknz]

Hey everyone,

I saw the famous footage that Le Mans reposted of the tank slapper.... That got me thinking, how many of you have had a tankslapper and what were the consequences....?? also were there instances where you rode it out, ie accelerating to lift the front wheel..? I hope like anything it wont happen to me, but im sure it will one day.......

Cheers everyonce

Late last year I was test riding the 03 CBR600RR on one of the backroads around Canberra. Went to overtake one of those not-so-small trucking bohemoths and would had to have been doing approx 140-150 at the time. Probably just had the front end come down on one of those tits in the road and it was all on. Have no idea to this day how I saved it, but it all came together and I was so cacking myself that I got off the bike to have a think about things. The aforementioned truckie pulls up and asks me "that was pretty Impressive, how the f#$k did you save it?". "I got no freaking idea!" and we both had a good laugh.

[DEATH_INC.]

I forgot to mention I had a biggie on the ZX12 doin about 200k when I landed it from a wheelie with the bars turned.....couldn't physically hold on to it,it was so violent that i had one foot on the road(thank f**k race boots slide eh)and was just hanging on with my knees.....
One of my mates got spat off an XJ750 a few years back at about 180kph when he hit some bumps on a bridge going into whangarei too.....

[Two Smoker]

Shit those are some pretty scary events as well as some pretty amazing saves..... It seems the majority of them started when in mid corner and hitting a bump or popping the wheel and ladning with the bars turned keep the tank slapping stories coming guys i think people might be learning from it (i certainly am.....)

Cheers

Two Smoker