Tank Slappers

[DaveW]

I want to encourage everyone with a sport bike to research and then purchase a steering dampener. I have witnessed far too many injured riders and destroyed bikes resulting from lack of good steering dampener.

Last February at TWS one of our riders had just totally rebuilt his entire bike. On his second session out, he was half way down the straightaway when he got into a tank slapper that totally destroyed his bike. He was very fortunate to not have been seriously injured. He was going 120 mph when it happened.

YouTube - Terrible Bike Crash

YouTube - Terrible Bike Crash

[loonytoons]

+1, even though my Honda came with a factory electronic steering dampener I upgraded to something better.
in the video above the riders rear spring snapped causing the loss of control but it's still a great reminder of what can happen. I'm glad that he lived, that was a nasty crash.
How about those tank slappers? Can they happen to you?...................

YouTube - TANKSLAPPER! MAM 6/28/10

YouTube - TANKSLAPPER! MAM 6/28/10

[D03Cobra (SBOSS)]

Most people try and correct/stop a tank slapper once it starts. All that does is make you crash, you can not stop one with your hand and arms. Had one happen to me when I was pushed wide at Houston. I remembered an instructor telling me once that if a tank slapper happens loosen up your grip and allow it to ride out, well thats what I did and bike regained control and I got back on the track and finished out my session.

[tripleracer]

It is best to be neutral when you get all slappy. Do not roll on or off, maintain throttle. Front brake can help, it completely calms down my motard, but thats not always the case so I don't recommend it. Do not tence up. I combat the "pucker factor" by taking a deep breath whenever anything stupid starts to happen, this keeps fresh oxygen going to the brain and keeps you loose. most of the time you find that by the time you have taken that breath a slapper has passed through the bike and you settled.

My longest slapper was just more than two breaths doing 140-150 at TWS. I full throttle clutchless shifted into 6th and the bike slapped out. I tried to go neutral but rolled off slightly and the bike went nutz braking the steering stop off the frame, I rolled back in the tiny bit i accidentally rolled out and a millisecond later they bike righted itself. My feet came off the pegs but I was holding with my knees and never broke the tuck. This was the second bad slapper that day and the first reminded me that a tank slapper can and will knock you pads away from the rotors. I had to pump my brakes going into turn one.

[loonytoons]

My worst was on the street when I had my TL1000. i was coming off the George Bush toll road exiting to Southbound I-35. I loved going over that long wide sweeping bridge leaned over and hard on the gas. The bike was fresh out of the shop 2 days earlier for a problem with the gas tank. They had a recall for some venting issues and they assured me it was fixed...... nope, while at a good lean and speed the bike died. If you have ever had a motor shut off at 10,000 RPM's then you know what happens. The bike lurched and the rear stepped out, as I pulled in the clutch and shifted my weight to regain control the bike began to tank slap violently. I started heading towards the outside wall and thought that this was it. I was for sure going to be tossed over the wall and onto the highway 200 feet below. My only option at that point was to ditch so grabbed for the front brake. The bike stopped tank slapping and somehow i was still rolling, i coasted to the bottom of the bridge, put the kickstand down, took off my helmet and gloves and lit up a cigarette. I sat there for over an hour staring at the bike with the bridge in the background and cars below on the highway. I popped the gas cap on the bike to let it vent started it up and rode home. The next day I took the bike back to the dealer and explained what happened, put the keys on the desk and got my money back.
I don't know what saved my rear, I don't know if it was the front brake or the bike and factory dampener... I do know I was very lucky to have not been killed.
When I got my new bike GSXR750 I went back to the very bridge and hauled tail around it just for piece of mind.

Tank Slappers suck. What are some things other then a good steering dampener you can do to avoid them?

[Pattrick]

had one at Cresson last year on my CBR 1000. coming out of ricochet at 100+. I hit that bump on the exit and went into a slapper.
nasty, I was out of my seat and headed over the bars when I finally let up on the bars.. the bike settled right down. Most of the problem was caused by being to stiff on the bars while setting the front down, leaned over , exiting a turn. The other part was a check of my steering head bearings. After 2 seasons they were loose. I changed from the cheap oem ball bearings to a a set of tapered roller. Bike geometry has a bunch to do with it. I had Jim Cambora help me adjust most of mine out. so geometry and check the head bearings.

[Instructor GUY]

yes scary times.. please get your sterring bearings adjusted regularly especially with track time. i find many loose ones and always replace mine with ALL BALLS KITS..50$ cheap insurance to keep the front wheel planted..Another old Guy, who has been there..

[Bimmerx2]

Interesting discussion, my little bit to add...

My crash at Cresson was coming out of Ricochete and no one saw what happened and I have no memory of the actual crash. Based on what others have said, the crash location and some evidence on the bike it's pretty clear that I got into one those infamous slappers out of that corner and eventually lost it when I ran off track.

I have a steering damper and the steering bearings are solid. BUT... I cranked back the damping a notch just before that session. I did that because during tech inspection I was told that "it's too high" and it should be "as soft as possible" and still work. Being an open minded newb to the track world I took the advice and I'm pretty sure that was a very bad idea. I had never had a problem, until that session. Maybe the setting was pretty close to the limit for how I ride?

To be clear - I'm not saying that the change in the damper setting caused the crash or that the advice was bad. Hell I could have run over a rabbit for all I know. However, it does bring up the question of "How do you know if you have just enough damping?".

I mean really, if you're aren't experiencing instability or don't have a tank slapper it could be that the damper is set to 'just enough', it's way too much, or you just never got into a situation to cause a problem. On the other hand, the only way to know you don't have enough damping is when you get at least some shake but it's a small step from a little head shake to a full blown tank slapper and that's not a test any of us want to be doing.

[tripleracer]

1.Your bike should not need a steering damper. If you think you absolutely need it your set up or your riding style is causing problems.
2. Steering dampers are not meant to prevent head shakes. They are intended to damp out the oscillation to keep from slinging the brake pads away from the rotors.

[AdamkyzfR6]

do they make a damper for a buell 1125CR?? been looking and cant find one?