Tank Slapper

[SlimDizzleATL]

Anyone dealt with one? What causes it? I know it happens at speed. I feel like I wouldnt know what to do. Any good advice? Thanks.

[TroyBoy30]

aint that why god my steering dampers? Wobble or shimmy begins when some otherwise minor irregularity accelerates the wheel to one side. Like not having the front straight when coming down from a wheelie?

http://en.wikipedia.org/wiki/Speed_wobble

[everyday3]

^ that or pot holes uneven pavment wrong rider input. lots of things cause it best thing you can do is stay calm and let the bike work it out or get a steering stableizer.

this is what I have on my bike and love it


http://www.hyperpro.com/index.asp?page=steeringdampers

[steve c]

Tank Slapper is a generic term. Could be two or three different things.
1) Head shake: caused by picking up the front wheel + _____________ insert your favorite triggering mechanism here. Mine is hard acceleration while partly leaned over with front up - front touches down at a slight angle = head shake. Result slight distraction for rider. Rider promises god he'll purchase steering damper before next track day.
2) Frame shake: Nail throttle on corner exit, back end breaks loose, then hooks-up at a slight angle. Energy is transferred to the front end jerking the frame back and forth until the two wheels are again lined up, or the rear end looses traction again. Shins impact the sides of the motor ususally. Just bruises.
3) Death wobbles: this occurs on older twin-downtube frames under hard cornering. The suspension compresses, the frame/swingarm twist under the load then unload (similar to a highside rebound, but without the resulting launch of the occupant). The suspension compresses again, the frame twists, and then unloads, after the 3-4 repetition the amplitude becomes smaller, but the frequency increases - its trying to rip the handlebars out of your hands. At this point you have some choices to make. I've never had it happen in a straight line, but I've seen video from IOM - not pretty. No advice to offer there. If you're cornering you can 1) Hang on and hope it doesn't throw you off or rip the bars out of your hands or 2) stand the bike up, apply as much brake as you dare and hope there are no solid objects in your path because any chance of making the corner is now gone.

- Steve

[Todd]

let me just say, dont go thinking a steering damper/dampner will eliminate tank slappers. I know first hand, that is NOT the case.

Steve, where you say you hope it doesnt rip the bars out of your hands? Actually, that would be the BEST thing to happen. If, and i say IF your mind can tell your hands to let go of the bars, 9 times out of 10, the tank slapper will stop almost instantly. I was told when i first started racing, that if i ever experienced one, to attempt to let go of the bars. Your mind is gonna be saying "HANG THE F ON!!!!", but if youre able to relax your grip, it will usually stop before it throws you on your head.

[Seca]

Anyone else ever get tank slapper coming out of T5 at RA while using the rumble stip? Only time I have ever had a bad tank slapper was there. A couple of times actually. Luckily the front tire came back up off the track cresting the hill and it calmed down.

[Seca]

let me just say, dont go thinking a steering damper/dampner will eliminate tank slappers. I know first hand, that is NOT the case.

Steve, where you say you how it doesnt rip the bars out of your hands? Actually, that would be the BEST thing to happen. If, and i say IF your mind can tell your hands to let go of the bars, 9 times out of 10, the tank slapper will stop almost instantly. I was told when i first started racing, that if i ever experienced one, to attempt to let go of the bars. Your mind is gonna be saying "HANG THE F ON!!!!", but if youre able to relax your grip, it will usually stop before it throws you on your head.

I read someone where once that it is your body moving with the slapper that will continue to make the slapper worse....?

[SlimDizzleATL]

Tank Slapper is a generic term. Could be two or three different things.
1) Head shake: caused by picking up the front wheel + _____________ insert your favorite triggering mechanism here. Mine is hard acceleration while partly leaned over with front up - front touches down at a slight angle = head shake. Result slight distraction for rider. Rider promises god he'll purchase steering damper before next track day.
2) Frame shake: Nail throttle on corner exit, back end breaks loose, then hooks-up at a slight angle. Energy is transferred to the front end jerking the frame back and forth until the two wheels are again lined up, or the rear end looses traction again. Shins impact the sides of the motor ususally. Just bruises.
3) Death wobbles: this occurs on older twin-downtube frames under hard cornering. The suspension compresses, the frame/swingarm twist under the load then unload (similar to a highside rebound, but without the resulting launch of the occupant). The suspension compresses again, the frame twists, and then unloads, after the 3-4 repetition the amplitude becomes smaller, but the frequency increases - its trying to rip the handlebars out of your hands. At this point you have some choices to make. I've never had it happen in a straight line, but I've seen video from IOM - not pretty. No advice to offer there. If you're cornering you can 1) Hang on and hope it doesn't throw you off or rip the bars out of your hands or 2) stand the bike up, apply as much brake as you dare and hope there are no solid objects in your path because any chance of making the corner is now gone.

- Steve

Good explaination. Hope to never have this situation occur.

[Todd]

I read someone where once that it is your body moving with the slapper that will continue to make the slapper worse....?
partially correct. theres no way ANYONE's hands/arms can oscillate back and forth as fast as the bars are going in a tank slapper, much less at the same rhythm, so as a result of hanging on to the bars, its shaking your body so violently, that now, not only is the front end going back and forth, but your body is making matters worse by transferring that energy all the way to the back of the bike.

[Seca]

partially correct. theres no way ANYONE's hands/arms can oscillate back and forth as fast as the bars are going in a tank slapper, much less at the same rhythm, so as a result of hanging on to the bars, its shaking your body so violently, that now, not only is the front end going back and forth, but your body is making matters worse by transferring that energy all the way to the back of the bike.

IF I remeber correctly that is what the article was saying. Makes sence to me...

[Todd]

oh, and yea, i sometimes get a bit of head shake as i crest the hill out of T5 at Road A. Even on a 600, i have to literally stand on the pegs with my head on top of the windscreen to try to keep the front end down, but if the front tire is just a tad out of line with the rear as it comes back down, it'll head shake pretty good. Hell, for me, when it does that, thats my way of knowing im gettin' it right. :up:

[Seca]

oh, and yea, i sometimes get a bit of head shake as i crest the hill out of T5 at Road A. Even on a 600, i have to literally stand on the pegs with my head on top of the windscreen to try to keep the front end down, but if the front tire is just a tad out of line with the rear as it comes back down, it'll head shake pretty good. Hell, for me, when it does that, thats my way of knowing im gettin' it right. :up:


I tried the Mladin line, over the rumbles nick the edge of the grass where the cross over road starts on my TLR...took me a few times to get it right...and had to wash my leathers twice... :D

[Todd]

LMAO! i hear ya, Brett!! Ive tried that line, me no likey, but i do know it works!

[GEORGIADAWG]

Anyone else ever get tank slapper coming out of T5 at RA while using the rumble stip? Only time I have ever had a bad tank slapper was there. A couple of times actually. Luckily the front tire came back up off the track cresting the hill and it calmed down.

yeah i get it on my R6 during racing conditions. I just leaned forward on the bike and grabbed all the throttle i can. The truth be told every thing you are suppose to do to save a tank slapper is something that 9 times out of 10 won't work on the street. Being so restricted on space and obsticles doesn't give the proper amount of time to relax and do what's needed to save it.

[Seca]

Personally, I think T5 was on of the hardest corners at RA to perfect. Even more so with people in front of you. Saw a few guys loop it coming over the hill. Dzone has a great video of a track day we were at. Dude on a R1 was haulin past everyone. Passed Bill and I in T4 and then looped it on wheelie hill. Bill did a fatastic job staying with him sliding....

[TLR67]

The bike will work on its own.... Notice how this poor soul tried to hang on....
http://www.youtube.com/watch?v=LZ1srcQMa_0

And probally the best save ever.....

http://www.youtube.com/watch?v=HtjQ4SK4GXk&feature=related


Well I guess Rossi in his younger years was even better...More of a highside but still...

http://www.youtube.com/watch?v=6Fa0GmdSN4A&feature=related

[Back Marker]

back in 1992, i bought a new zx7 from the dealership. i was doing a good 80mph on the HW when i hit a tank slapper. i lost my grip and it settled down on it's own. when i got home, i inspected the steering head and it had too much play on it. i can feel it moving forward and back while tapping the brakes at low speeds. to fix it, i replaced the steering head bearings and tightened it to spec.

i've also had tank slappers on my 1986 gsxr 750, a steering damper fixed it.

-a|ex

[Over TWO Customs]

When in doubt , throttle out.

[SpecV]

When in doubt , throttle out.

On tank slap that is the worse thing to do. I been in a lock-to-lock tank slap many times

Relax(try to let go of the steering) .Even Accel out of it (power out)

Keep your feet on the pegs and firm if you loose your feet you might just fall off

[Over TWO Customs]

Relax(try to let go of the steering) .Even Accel out of it (power out)



Yes, when in doubt, throttle out. I have encountered tank slappers on the street from poor wheelie execution. Hit the gas and hold on. It will work itself out.

[Todd]

On tank slap that is the worse thing to do. I been in a lock-to-lock tank slap many times

Relax(try to let go of the steering) .Even Accel out of it (power out)

Keep your feet on the pegs and firm if you loose your feet you might just fall offthats exactly what he meant, throttle out=give it more gas. It takes the load off the front.

[kahearn]

I had a massive one on T5 at RA during my first WERA race. I came off the rumble strip, the front wheel came down, and WABAM. I tried to keep the throttle pinned wide open as the bars shook violently but i was also trying to steady them myself, which probably hurt my situation. They had to red flag the race and the medical staff said I was "dazzed," but i dont remember anything from thinking, "shit, i cant believe im crashing" to being in the medical building at the track telling the lady my name and address like nothing had happened. I specifically remember looking down at my boots and thinking, "blast i must've crashed."

I believe my damper failed b/c i had my bike stolen and recovered a couple months earlier. The ignition was gone, my upper triple was cracked, and I was really busy with school so i had my insurance company send the bike to a dealer to fix all the damage the thief had done. I suspect the technician at the shop failed to put locktite on the set screws of my damper when he reinstalled it...and i didnt check them unfortunately. The resulting damper fail:
http://i238.photobucket.com/albums/ff40/kahearn3/WERA%20RA%20race%201/IMG_2720.jpg

I've learned my lesson on that, though of course i dont know the damper would have saved it. Probably.

http://i238.photobucket.com/albums/ff40/kahearn3/WERA%20RA%20race%201/IMG_2717.jpg

I was amused by this post on the WERA board after that weekend.

Originally Posted by vance View Post
WOW!!!!
Y'all are some crazy f#ckers!
This was my 3rd weekend, but I think it was my first REAL race weekend.
I was right next to the guy who had the massive tank slapper at the top of the hill past the esses.
Hope you're OK man.

woot for tank slappers

[ramm]

Damn Kyle, crazy stuff. Welcome, by the way.

[joemama]

Years ago I had a nasty tank slapper on my old Hawk GT while getting onto 75N. I was coming up entrance ramp, almost to 75, took my left hand off the bar to turn my head so I could see if anything was coming...then it was like the bike was trying to do everything it could to throw me off! I COULDN'T grab the other bar if I had thought to, it was moving so fast. I had only been riding for a few years, so I was still a newb too. I held onto the bike as long as I could then me and the bike both hit the asphalt. I landed on the bike on my chest, then slide down onto the road. Thats where I started to slide on my forearms, T-shirt & no jacket (yeah I know SQUID!). I learned my lesson, just took some roadrash to drive it home. I slide off to the side of the road but could have very easily went into the interstate. Wasn't any fun, belive me. The whole thing happened so fast, and was so voilent, that I felt like I was along for the ride. I'm still not sure what caused it. I wasn't speeding, wheelieing, or anything you would expect to start one. I had done the same manuever thousands of times before and since. Whatever the cause, I hope to NEVER experience one again!

[Seca]

Marc's mom gave me a taint slapper once...

[GEORGIADAWG]

Marc's mom gave me a taint slapper once...

:crackup::rocker:

[SLLaffoon]

If any of you guys stop by MSP, ask Rod Burr about the tank slapper he had in RA turn 5 a couple years ago. He didn't crash, but he did break his wrist.

[Todd]

Stephen, i crashed at Tally 4 years ago and broke my hand. About 8 weeks later, i was back at the track, Lee had just gotten his 06 R6, got it race prepped (everything but the damper), to me to take it out for a session. This was old config running clockwise. I had just passed Ed Bargy going into the sweeper and snapped the throttle WFO on exit. Still leaned over the front end came up just a bit then touched back down, Ed watched me flail around like a wet washrag on the R6 it sent me into such a slapper, not having a damper on it, i WAS the damper. Damn thing beat that left hand so much before it finally settled down (i didnt crash), that i couldnt ride the rest of the day without pain. I THOUGHT i had rebroken it. Ive heard of people breaking their hands before getting in such violent slappers, and after that day, i realized how.

[jtryz]

i thought a tank slapper was a funny joke... LOL )not funny)

how about this
http://www.youtube.com/watch?v=f10ZsAaxBlc&feature=related
that sucks

[061k]

dont forget to test your front brakes after a slapper,you dont need another surprise when its time to slow or stop. and remember if your on the street obey the law.......................NOT!!!!

[TLR67]

I did a Waist Stoppie on Secas Mom once....

[061k]

there are some busy mamas out there for sure. anybody got pics???