Topic: how do you recover from a tank slapper?

[xsmooth69x]

just wondering if anyone had an personal experience recovering from one of these or if anyone knows how to recover

[fmctm1sw]

pray... 

[sick_seven_fifty]

I had one once. That was about 10 years ago...I was fairly new to motorcycles then.  I was going through a pretty tight curve following a friend...going a bit too fast after a light rain.  Rear tire hit a slick spot and slid out a bit.  When it caught traction it brought the bike up straight and into a tank slapper.  I was now headed across the curve towards the ditch.  I just held onto the bars as tightly as I could...not trying to turn one way or the other.  Just tried to hold firm to stop the bars from slapping.  It eventually straightened out.  By the time I got control of the bike, I was in the other lane, towards the outside of the lane.  A truck came from the other direction, and we played chicken for a bit.  The truck didn't veer, so I had to....straight down a ~20 foot embankment...just before a bridge. I kicked the tail end of the bike out as soon as I went off...let the bike slide down, while I rolled behind it.

I was very lucky.  Other than a bruise about the size of a small plate on my hip, I walked away unharmed except for my pride.  I even rode the bike home after I let it dry out a little bit...it flooded out on its side.

Anyway...I know you haven't ridden a bike yet, so take these kind of stories and learn from them...pay attention to what you're doing and you'll be fine...and don't showboat.

[sick_seven_fifty]

By the way, that bike was a Yamaha R6, not a CB750...I don't know what difference that would make in recovering from a tank slapper, but it's the only experience I got.   

[xsmooth69x]

By the way, that bike was a Yamaha R6, not a CB750...I don't know what difference that would make in recovering from a tank slapper, but it's the only experience I got.   

doesn't the r6 have a stock steering dampener on it?

or maybe that was only 600rr ninja or gixxers lol

[dave500]

try not to encounter one in the first place.

[sick_seven_fifty]

By the way, that bike was a Yamaha R6, not a CB750...I don't know what difference that would make in recovering from a tank slapper, but it's the only experience I got.   

doesn't the r6 have a stock steering dampener on it?

or maybe that was only 600rr ninja or gixxers lol

No, the R6 didn't have a stock dampener (at least on the 2001 models it didn't.)  And a tank slapper is a tank slapper...main difference would be the rake angle between the two bikes.  And if anything else, I'd think it would be easier to recover on a CB750 because of the leverage you have with the handlebars vs. the clip-ons of the R6.

[xsmooth69x]

By the way, that bike was a Yamaha R6, not a CB750...I don't know what difference that would make in recovering from a tank slapper, but it's the only experience I got.   

doesn't the r6 have a stock steering dampener on it?

or maybe that was only 600rr ninja or gixxers lol

No, the R6 didn't have a stock dampener (at least on the 2001 models it didn't.)  And a tank slapper is a tank slapper...main difference would be the rake angle between the two bikes.  And if anything else, I'd think it would be easier to recover on a CB750 because of the leverage you have with the handlebars vs. the clip-ons of the R6.

unless your going to put clubman or clip ons, on the cb750

[Fritz]

Luckily, I never had one.
The theory says that the bike will straighten out by itself, so you should try to relax your arms. Tightening you grip will transfer the oscillations to the rear end of the frame and your body and it will be even harder to stay on the bike.
So relaxing your arms and using your leg muscles in order to stay on the bike while the front wheel is working on finding a straight line should do the trick...
... in theory.
But I guess, if you ever face a tank slapper in a curve, you don't have time to think about theory ...

[sick_seven_fifty]

Luckily, I never had one.
The theory says that the bike will straighten out by itself, so you should try to relax your arms. Tightening you grip will transfer the oscillations to the rear end of the frame and your body and it will be even harder to stay on the bike.
So relaxing your arms and using your leg muscles in order to stay on the bike while the front wheel is working on finding a straight line should do the trick...
... in theory.
But I guess, if you ever face a tank slapper in a curve, you don't have time to think about theory ...

I'm not an expert, or a physicist for that matter, but I would think that relaxing would be a bad thing.  Think about it...what does a steering dampener do...it reduces the ability of the front end to make quick sudden movements by dampening.  I would think a couple of stiff arms would dampen it much in the same way.  With that said, it's certainly next impossible to stop one and much easier to prevent one...but I don't think I could force myself to relax on the bars in the middle of one.

[sick_seven_fifty]

To be fair, I did find text backing up Fritz's post:

The easiest way to avoid tankslappers while accelerating over bumpy pavement is to—believe it or not—keep a relaxed grip on the bars. Relaxing your grip on the bars means you must lean forward in order to assist in keeping your torso stabilized. This helps put more weight on the front end, which keeps the front tyre on the pavement. Since you’re not using your arms to stabilize your upper body, get your weight onto the footpegs so that you can get your body as far forward as possible; this also allows you to grip the tank with your knees for more stability.

If you do get into a tankslapper, keep your weight forward and—as hard as this sounds—maintain a relaxed grip on the bars. Let the motorcycle’s chassis deal with damping out the oscillations. Don’t try to be a human steering damper; you’ll only make the problem worse. Tankslappers can definitely soil your undies; but if you’re able to deal with them correctly, you’ll usually ride through them before you know it."

But I guarantee you, in the event of a tankslapper, I won't be relaxing...and neither will you...haha. 

[Greggo]

I had one after I hit an unavoidable sand dune blown into the roadway.  Couldn't see it because of the car in front of me...not fun.  I was going in a straight line, so at least there's that..

Plant your weight on the pegs, shift your ass to the back of the bike, and PRAY.  Considering how many stories I've heard of them happening on newer sport bikes, I feel confident stating that a steering damper will not prevent one of these.

[Fritz]

Think about it...what does a steering dampener do...it reduces the ability of the front end to make quick sudden movements by dampening.  I would think a couple of stiff arms would dampen it much in the same way.

Yes, I think it is not obvious. Like the fact that you have to steer to the left (push on the right end of the handle bar or pull on the left end) to make the bike lean to the right. The bike's leaning to the right is a 'correction' movement to your forcing the wheel out of its line. Every force is creating a counter-force

A few months ago, I've read an excellent article written by a female German motorcycle racer about how to react to tank slappers.
Unfortunately, I cannot find it any more, so please bear with me (and my poor English), if the following is not very 'scientific':
Most cases of tank slappers are caused by the same problem: The front wheel is forced out of the line that the bike is following. Let's say it lifts off the ground and you twist it slightly to the right while it is in the air.
When the wheel touches down, a strong and sudden lateral force is 'attacking' the front end. In order to compensate this force, the wheel has to turn to the left. Now it faces a lateral force in the opposite direction turning the wheel to the right and so forth. While slapping from one side to the other, the bike is 'working off' these forces until they are 'shaken off'.
If you hold firmly on the handle bar while the front end is trying to cope with the lateral forces, you might dampen them but you will also transmit these forces into the frame and your body and make the situation worse for you and the bike. Putting more weight to the front wheel will make it 'heavier' and create more inertia helping to get rid of the lateral forces.
So my feeble theory is that a steering damper might stop the slapper faster but it might also make the bike shake more violently because it transmit forces into the rear.
But it prevents oscillations that slowly build up at high speed.

I found this video interesting as the rider says "First and foremost, this was at the beginning of the day and I was nowhere near as loose as I should have been on the bike. Way too much weight on the bars."

<a href="http://www.youtube-nocookie.com/v/GvHtChodNk0?version=3&amp;amp;hl=en_US" target="_blank" rel="noopener noreferrer" class="bbc_link bbc_flash_disabled new_win">http://www.youtube-nocookie.com/v/GvHtChodNk0?version=3&amp;amp;hl=en_US</a>

Let's hope that none of us will face a situation like this.

Cheers
Carsten

[Bahumut]

^ I've been to that track.. That tankslapper looked bad, but it's not as scary as all the turtles an foxes that meander onto that thing.  Sheesh!

[splitt]

The biggest problem with these older bikes was the amount of give with the forks and frames. When large diameter inverted forks and box/trellis frames came along, that lessened the chance for a tank slapper unless the bike was really pushed to it's limits.

Holding on as firmly as possible, sliding your weight to the rear and not panicing by hitting the brakes is the key to saving a tank slapper.

[Dyrden]

Pin it!

Seriously.  Lots of people will tell you lots of different things.  Its very counter-intuitive, but its worked for me on more than one occasion.  Were not talking about a little head shake either, were talking slappers.  Lock to lock on the steering 10 times quicker than you could ever do it yourself.  The theory is something like this, WOT takes the load off the tire and hopefully lets it settle back down.  Also kind of a weird side effect, make sure to pump your front brake after.  Its taken several pulls of the front brake to get pressure back on the pads(I assume after they were pushed back into the calipers somehow). 

And to restate some of the above: slappers are usually just the bike complaining about some knuckle head thing the rider did.

[WarwickE36]

a 6-pack of high quality beer, not talking bud or bud light here people, some Belgian Trappist, southern tier 2xipa, in a pinch some micro brew .... and a bag of pees to the afflicted areas

[HondaMan]

Go into the bushes near the road, take off your pants, throw the shorts away, put the pants back on, ride on as if nothing happened... 

And then don't push the mileage on the tires so far, next time. 

[crackerbat]

I've had a few slappers on my old zrx (bike is notorious for needing a dampener).  If you have the presents of mind to pin the throttle and ride it out.. it's always worked for me.

[camelman]

Tank slappers can be induced by three main harmonics in the bike.  The typical ones involved the front wheel oscillating back and forth and kick up around 27-33MPH, 75-85MPH, and again around 120MPH.  If you end up in that situation, then either speed up or slow down to get out of the speed that excites the harmonic.  If you have plenty of power, then speeding up is probably easiest.  If you are low on power, then chop the throttle and slow down.  You really won't have much time to react to a tank slapper other than throttle response, since they are so violent and immediate.

Bicycles can get the same effect.  With a bicycle, if you find yourself in a weave or a "slapper", then the only real option other than braking is to stop the waveform that is going through the bike.  You can do that simply by clamping your knees around the top tube.  That effectively adds a node to the waveform, which means that an even more powerful wave is needed to excite a harmonic.  You can think of it like a jump rope.  It is easy to make shake a jump rope to get a curve that goes up and down.  It takes a lot more strength to get a node to stand in the middle, and is almost impossible to get two nodes to stand in the middle.  That's the same theory with clamping your legs on the top tube of a bicycle.  You make it too hard for the existing energy to induce a harmonic.  I don't know if this would actually help on a motorcycle, but it couldn't hurt to try as you are twisting your throttle or rolling off it.

FYI, I've had a couple tank slappers in my life.  My first was at 80 on my 1982 Seca 750.  The cause of that was a sticky swingarm pivot.  It came on immediately, but I just gassed it and got through.  I had a few recently with my 350f, but they were the slow weave style instead of the crazy handlebar harmonics.  I just chopped the throttle and slowed out of the speed range, and they were caused by a worn swingarm.  Hondaman fixed that problem for me.  ;-)

By the way, you'll notice that the tankslapper in the video ended as soon as he started to slow down.  They usually only occur at given speeds.  So, if you find yourself in one, just change speed!

Camelman

[CafeDawg]

Smooth go back over your thread, I think Twotired had a link to that article that Fritz referenced.  Someone mentioned tankslapper cause of your bent frame and it went from there.  Your not asking this question because your still thinking of running that frame r u?       
CD

[HondanutRider]

A long time ago my CB77 had this problem, likely due to the wheels being out of alignment caused by a bent swing-arm.  At any rate, whenever I approached a high speed, at about 85mph on that model, it would start to violently weave as the front wheel went from side-to-side, pretty well to the stops.  No matter how hard I held the bars or tightened the steering damper (stock mechanical on that model), it would oscillate uncontrollably and scare the "heck" out of me.  It was as if the bike was about to flip me off. 
If I braked, the oscillations got worse - and at 85 there wasn't any throttle to open.  It seemed that any sudden change made things worse.  So, I held on and slowly let off the throttle and let it settle on its own.  Fortunately, I never had it crash...but I never found its true top end (which likely was a good thing too ).

[Tom in Newcastle......Ontario]

1983 cbx550f,was heading down the 401 in 1984 ,fresh smooth pavement,kissing the bars trying to get as low as I could,to go as fast as I could,

I thought that I was going fast enough and decided to back off,so I sat up(dumb) and I think I acted like a parachute. when I did that I took the weight off the front wheel.and started to slap.

If I remember correct I tried holding the bars and then tried cracking the throttle but there was nothing left,the slapping went through the whole bike and the back end started to dance ,ended up throwing me to the ground doing 80 mph plus.

I remember seeing the sparks flying off the engine guards,and me and the bike sliding straight down the road.

My bother-in-law was behind me on his RD 400 and said that when I started to slow down I tried standing up and ended up doing a flip and landed on my heels.....still hurts.

Full face helmet,Leather bike jacket,jeans,leather gloves...only one scar and that is where my right glove rode off my wrist.......

My daughter was 6 months old and that ended my riding until she was 17 .....

Things I learned .....protective clothing helps.........and engine guards are consumables..........Try to ride a bit smarter..........speed is fun but it can also hurt..

[xsmooth69x]

Smooth go back over your thread, I think Twotired had a link to that article that Fritz referenced.  Someone mentioned tankslapper cause of your bent frame and it went from there.  Your not asking this question because your still thinking of running that frame r u?       
CD

good observation hhahahaha but no there was another thread that had that video posted above and there is always all this tank slapper talk but no how to recover so i thought id just see what people say. i googled it read some articles but they all said different things

one article said to put weight on your pegs and lean forward to put weight on your front end

i am going to put the bike back together on the "bad" frame and ride it to see if all my other bike components work. im not going to be doing like 100mph runs or anything

but im going to ride it to some harley shops and chopper shops for them to look over the frame and also my spare frame. if not i was quoted $100 for another titled frame

[xsmooth69x]

1983 cbx550f,was heading down the 401 in 1984 ,fresh smooth pavement,kissing the bars trying to get as low as I could,to go as fast as I could,

I thought that I was going fast enough and decided to back off,so I sat up(dumb) and I think I acted like a parachute. when I did that I took the weight off the front wheel.and started to slap.

If I remember correct I tried holding the bars and then tried cracking the throttle but there was nothing left,the slapping went through the whole bike and the back end started to dance ,ended up throwing me to the ground doing 80 mph plus.

I remember seeing the sparks flying off the engine guards,and me and the bike sliding straight down the road.

My bother-in-law was behind me on his RD 400 and said that when I started to slow down I tried standing up and ended up doing a flip and landed on my heels.....still hurts.

Full face helmet,Leather bike jacket,jeans,leather gloves...only one scar and that is where my right glove rode off my wrist.......

My daughter was 6 months old and that ended my riding until she was 17 .....

Things I learned .....protective clothing helps.........and engine guards are consumables..........Try to ride a bit smarter..........speed is fun but it can also hurt..

so did your face scrap the ground?

because i bought this helmet... its not a full one or a half one but its an open face