tank slap

[Bassil Duwaik]

has anyone ever done anything to prevent a tank slap from bringing you down? Not talking about what you could do to prevent one before it happens (i.e. suspen, dampner, ect ect). Once you start getting a tank slap is it best to hit the rear brake? the front? drop the bike and lean? perhaps gun the throttle? Or is it just something you have to ride out and pray you don't go down

[pauliep]

my friend said when that would happen he would just fight it with th handle bars to keep it straight

[atrainthornton]

if you hit either brake, you will hit the pavement. Stay on the gas or increase if you can to keep the front end light and keep your hands light.
I had tank slap at 60 mph west bound pecos on ramp to 36. I went over a man hole cover that was NOT level with the pavement while leaning the corner and BAM.....those few seconds seemed like forever and was not able to truly think but react. I actually looked down at my bars and it all seemed like slow motion.....

[dattaway]

I'd let go of the bars and hope it would sort itself out.

[Repsol a095]

This actually happened to me a couple weeks ago coming down from Rampart. I went into a left hander when the rear wheel started sliding. My handlebars were crossed up, and I gassed it up big time. I felt like I was dirtbiking, but slowly the bike started to right itself. I think the best thing is not to hit the brakes but slowly give it more gas.

[dchd1130]

Thankfully I havent had to experiance it on my street bike, but have on my dirtbike. I was on a hardpacked dirt road going full speed and the bars started slaping back and forth. I didnt hit either brake just tried to keep it up right and it finaly stabilized.

[Mel]

Hitting the brakes is bad, as is fighting it. If you have ever seen a wreck where someone started a tank slapper, if the rider is "ejected" from the bike, the bike will tend to try (and frequently succeed) in righting itself. Fighting it is going to have the worst possible effect on the situation, kinda like fighting and over correcting a skid in a car.

[lovinCO]

Have experienced some headshake/tankslaps, just got light on the bars and kept constant or slightly accelerating throttle. Clears right up. Same .02 here--fighting or muscling the bars makes it worse.

[BigE]

The best thing is to just keep steady on the gas, very light touch on the bars, hold the bike with your knees and look far ahead.



And praying helps a bit too

[pilot]

The following is a discussion on the whys of what is behind a tank slap. I find that if we understand what gets us there, in the first place, we have a better understanding of how to get out of it, before it even happens.

The geometry of a bike is designed to keep it from tank slapping (and by the way, there is no tank slap without a rider on board). That is, as long as everything is in good mechanical order, tight front end--which keeps the forks from twisting especially on older-style, non-inverted forks, and your tires are not cupped. Cupped tires will cause the front end to have an ever increasing wobble. That wobble will cause the front end to dive rapidly back and forth into a lean, which, when the brakes are applied will only get worse as the front end dives down and decreases the rake angle, which in turn makes the bike steer faster. This is a particular problem for the ZZR 1200's, of which I own. In this particular case I have to use my hands to act as a steering damper to keep the front end from ever increasing oscillations at road speed decelerations. Unfortunately, I have been in the precarious position of a tank slap, on hard deceleration and even simple engine braking in the straights. The luxury that many riders have, being able to take both hands off the bars for a stretch as they come to a stop light, gently cruising in, does not exist for the ZZR. In my bike's case this cupping causation, and it's solution, is generally opposite of what needs to be done to avoid a tank slap. BTW, there are "fixes" for this and I believe Nick Ninja has done many for his bike.

For most riders, the natural tendency is for the rider's body to try and balance itself and that means that every time the bars push to one side the rider pushes back. Then the bars go the other way and the rider pushes back on the other side. This is known as a "feedback loop". The action is akin to counter steering, in both directions, to excess. This, in combination with the applying the brakes, or snapping closed the throttle is a sure fire way to set up a high side. Which as previously mentioned usually starts out as a rear end slides out-- generally caused by excess lean angle (poor body position) and lack of contact patch on the rear at corner entry. Or, "spooling" up, causing the tire to develop more rotational speed than is required to maintain traction, as one rolls on the throttle through the turn. Spooling is also a technique used for several other advantageous riding techniques.

It is our natural reaction to: Freeze up, run away, and overreact to issues causing tension within our brains and bodies. In order to avoid these things or at least try and use them to our advantage we must practice the drill of what to do properly during our riding. Successive events of training and practice will help keep us from ending up in "that" kind of situation whether it be a quick stop, swerve or avoiding a high-side.

There is a lot to be said about staying on the gas. Most riders would agree that it is better to low-side than to high-side. Low-siding, either by front, rear or combination of both, is the precursor to the high-side. However, the rider overcompensates and goes to other side of the balance equation and plays Superman. Several occasions of post high/low-side events can be seen where the rider ejects from the bike and the bike "fixes" itself and rides into the sunset. Commonly referred to as ghost riding.

A particularly good example of staying on the gas can be seen in another application and this is most relative to Bassil as he operates heavy machinery. The front-end loader, commonly seen on many construction sites, has a tendency to bounce back and forth from its rear wheels to front wheels. The tires provide the only suspension on these machines and there is no real damping effect from them. This back and forth oscillation is magnified by coming off the gas and hitting the brakes. The only thing to do is get back on the gas. This application of power lifts the front end and cancels the wave effect from moving back and forth from the front tire through the chassis and to the rear tire and back again. Once the wave is canceled the operator can ease off the gas and on the brakes. A good operator can cancel this event in a matter of a couple of seconds. A novice can use up valuable time trying to get it under control.

Just like the operator of the loader, a motorcycle rider needs to practice the proper technique in order to decrease the chances of the wrong thing happening.

Staying off the brake, smooth throttle application, becoming "one" with the chassis by keeping the arms relaxed and the body positioned properly and limiting the effect of tension in the upper body will help avoid and thus recover from the progression leading to a tank-slap and resulting high-side.

Several videos are on the net of high-sides.

One final thing. If you've done all you can and find yourself about to eject off the top of the bike; you should do all you can to protect yourself. This means tucking your chin bar of your helmet against you chest, crossing your arms in front of your body to protect your vitals and tucking up your legs in a cannonball position. This will do several things: One, make you a smaller target for your bike to hit, two, keep your body parts from twisting around and all over, and three, allow you to "burn off" speed by tumbling end over end rather than using your arms and legs to smash against stuff.

This can be easily practiced with the aid of friends on a trampoline or by jumping into a pool. You can have someone call out low side or high side as you are in the air.

I've typed a bit and perhaps someone else could address how they handle low-side falls/slides.

If someone else has said similar ideas to this, please just consider it another style or method similar to trying on different shoes for fit and use.

The above is only to be considered as an option of numerous possibilities and I in no way take liability for your actions and resultant reactions. Please consider it similar to a write up or letter to from a reader found in a magazine.

Thanks for taking a moment to read this and good riding,
Pilot

[txrc51fatboy]

relax, dont panic and give alittle gas

[DavidofColorado]

I still don't know what a tank slapper is? I don't know what high-side or low side means and about the only thing I did understand is crashing. Could someone help me here?

I thought tank slapping is when you came off a wheelie and you smashing your junk into the tank.

[rybo]

Here is an extereme example

http://video.google.com/videoplay?do...arch&plindex=0

[Bueller]

http://youtube.com/watch?v=UVC9qsfO8Gw
Tank slapper
Highsides and T-bones

[DavidofColorado]

That looks bad. Thanks for shedding some light on it for me.

[Bassil Duwaik]

Thanks for the input guys. So for the most part what I gather it is advised to NOT hit either brake and try to lay off the handle bars. I'm sure it's something easier said then done. I've had problems with tank slaps before but never one hard enough to bring me down...well there was that one wheelie where I came down wrong. Thank you pilot for your input, and don't worry I will try not to get too rich off of you for reaching over my shoulder and grabbing my handle bars and making me hit the throttle;-p oh and RYBO I think the tank slap that guy got was because something went wrong with his rear suspension but nevertheless a good example of a tank slap

[DavidofColorado]

So could you avoid tank slap by putting your arms in a fixed position and not letting it swing one way or the other?

[Mel]

So could you avoid tank slap by putting your arms in a fixed position and not letting it swing one way or the other?

ummm, no...and good luck. Unless you are some kind of strongman body builder, you aren't going to prevent a 400lb bike in a tank slap from oscillating. Hence all the instruction on here saying ride it out, throttle it to get the front end light. And throttle doesn't mean crank it wide open either...anything on a bike, especially when you are in a "situation" has to be smooth, controlled movement.

[mushin_man39]

Wobble to tank slap is typically a consequence of a body position and form that is too stiff. This includes trying to make steering adjustments with the arms when the bike is in a turn. The bike is already turning, bumps, ripples, seams, and potholes will not change the direction of travel unless you make them! When racing, certain tracks have seams and transitions in the middle of the sweet cornering line. Imagine a race bike with stiffer suspension at a higher speed than your street exercise. A small track imperfection will have a greater effect on the bike. If the rider is loose and steering with his body, it don't matter. If the rider attempts to change lines, the wobble from the impact will turn into a slapper that may turn into a crash if not controlled. The control? Throttle maintenance and loose arms combined with lower body contact with the bike. The crash? Stay loose and spread out to spread the area of impact instead of full weight on one location, like, say you're all tucked up in a ball (think about your martial arts lessons). Also, spreading out will scrub speed off quicker and more than likely this will keep you off the retaining wall. I used this technique at 100+ at Hastings and the latest track day with the only damage being hot spots on my suit. Ask the poor bastards following me who got to witness the proper fall technique. For more info, please read Keith Code.

[DavidofColorado]

Don't most wobbleing that you see in those crash videos usually happen because of wheel bearing giving out? Thanks for playing myth buster with me.

[Mel]

Don't most wobbleing that you see in those crash videos usually happen because of wheel bearing giving out? Thanks for playing myth buster with me.

umm, no

[tarded400]

I also thought in a wreck you're supposed to play rag doll, because anything stiff breaks. I usually try and remain calm and relaxed and try and put more pressure where I know I have more padding. I was riding on dirt at higher speeds this weekend in deep sand, and it was floating quite a bit, and the bars would get to wobbling pretty bad. I tried to just let it go, but it didn't seem to matter and the suspension got all out of whack. I tried to fight it and it helped a little bit, but it wasn't a good feeling. I just tried to get back on the hard part of the road.

[DavidofColorado]

I almost high sided today. My rear brake locked up after I slowed and I felt it fishtailing around until it righted itself. Ok I didn't almost do it but it reminded me of this thread.

[lovinCO]

I was riding on dirt at higher speeds this weekend in deep sand, and it was floating quite a bit, and the bars would get to wobbling pretty bad. I tried to just let it go, but it didn't seem to matter and the suspension got all out of whack. I tried to fight it and it helped a little bit, but it wasn't a good feeling. I just tried to get back on the hard part of the road.

I think that's a different situation than what we were talking about. Tank-slapping on pavement is usually because of the front wheel striking something crooked at speed. Deep sand might require muscling.