Tank slapper at nhis

**Jayspeed** · 10-10-07, 05:53 PM

On my last trackday, I had a "oh shit" incident. After turn 7 my speed + reaching a hill brink + weight distribution + steering input = tank slapper. This was my first ever tank slapper and after watching the video it seems like it was nothing but it really felt out of control for a second. You can see the handle bars move and that movement at almost 100mph is alot. I blame my physical condition for I had a tough work day the day before and my legs were shot. I was lazy to not be on the tank at that moment. My Initial thought was, "is my front axle falling off?"
tank slapper

13 · 10-10-07, 05:59 PM

I'm guessing too much bar input was the biggest contributor to it. In the later laps of a race, if I get lazy and pull myself over the bike with my hands instead of my legs, even my hawk does that. Use your legs! And slow down, that's too fast for a trackday!

**OreoGaborio** · 10-10-07, 06:00 PM

Originally Posted by Stupidhawk007

I'm guessing too much bar input was the biggest contributor to it. In the later laps of a race, if I get lazy and pull myself over the bike with my hands instead of my legs, even my hawk does that. Use your legs! And slow down, that's too fast for a trackday!

+1... I used to get some headshake up there too... now that i use my legs more it's pretty much disappeared.

**JeffL** · 10-10-07, 07:01 PM

Oh cmon, he couldnt have been going that fast, he didnt even wheelie over turn 5.

The more and more I use my legs through there, the less and less I notice the crest of that hill and get the bike far less bent out of shape than I used to. :hellyeah

Dont be lazy, use the legs!

**wookie** · 10-10-07, 07:13 PM

I remember you talking about that at the trackday, insteresting to see the video.

So, is that the place other people experience wobble? (as compared to the entry to 9?)

Also, would a steering damper have helped.

**ku996r** · 10-10-07, 07:27 PM

I get it coming out of 10 sometimes over the pavement trans.

**Doc** · 10-10-07, 07:35 PM

Originally Posted by wookie

I remember you talking about that at the trackday, insteresting to see the video.

So, is that the place other people experience wobble? (as compared to the entry to 9?)

Also, would a steering damper have helped.

Yep! I used to get wobble there all the time, kinda expected it.... then the guys told me to use my legs and don't hold onto the bars too tight.

Wobble no more.

You don't need a dampner at Loudon.

**Doc** · 10-10-07, 07:36 PM

Originally Posted by ku996r

I get it coming out of 10 sometimes over the pavement trans.

I had that happen once this past weekend, first time ever and I was leaned over pretty good. Hit the bump and got a shake... shit myself but recovered...

**JeffL** · 10-10-07, 07:41 PM

Originally Posted by Doc

I had that happen once this past weekend, first time ever and I was leaned over pretty good. Hit the bump and got a shake... shit myself but recovered...

Put a stock rear shock on your bike and have the rear lift up and free rev the rear tire.

**Doc** · 10-10-07, 07:45 PM

Originally Posted by JeffL

Put a stock rear shock on your bike and have the rear lift up and free rev the rear tire.

Umm no.

13 · 10-10-07, 07:48 PM

Or, hit the t10 transition and have the front wheel come completely off the ground. That'll put you out of shape pretty quick. Joel can tell you how bad I looked during that.

**nerijusj** · 10-10-07, 07:49 PM

I did not have a tankslapper yet since I put a damper on the bike. On trackday I turned it up pretty high though ( setting at like 17 out of 22 clicks ) . I also wonder if that eliminates tankslappers or you can still get one with a damper turned way up?
And yeh on T5 2nd gear wot I'd get a 2 " wheelie, lol.

**a13x** · 10-10-07, 07:52 PM

I don't think I've ever done a lap around Loudon with having a wiggle thru that section. WEEE

Remember April first time 'racing' my RMZ motard and thing was slapping everywhere. Think some of the guys were watching me race and come over T5 The Hill and have it wagging all the way down to 6.

That was a good one thou Jaynnus, woohoo

**JeffL** · 10-10-07, 08:29 PM

Originally Posted by Stupidhawk007

Or, hit the t10 transition and have the front wheel come completely off the ground. That'll put you out of shape pretty quick. Joel can tell you how bad I looked during that.

I've wheelied in 7. Its not as fun as it sounds when the bike is supposed to be turning...... Hooray for bad riding technique!

**TTD** · 10-10-07, 09:45 PM

Things like this are why I recommend track riders get a damper... especially as they move up to the faster groups on sport bikes.

It can happen to anyone, anytime when the conditions are right. Better safe than sorry.

Two places I've seen it are 5 and 7. Either way, you're in for a scary ride.

**joeswamp** · 10-10-07, 09:59 PM

Yeah, my bars were shaking in both 5 and 7 (mostly 7) as I got faster during the last two track days. At the time I thought it was kinda cool but now that I reflect on it I'm thinking a damper might be wise investment...

**JeffL** · 10-10-07, 10:03 PM

Originally Posted by joeswamp

Yeah, my bars were shaking in both 5 and 7 (mostly 7) as I got faster during the last two track days. At the time I thought it was kinda cool but now that I reflect on it I'm thinking a damper might be wise investment...

Or just become a smoother, more efficient rider.

**joeswamp** · 10-10-07, 10:10 PM

Originally Posted by JeffL

Or just become a smoother, more efficient rider.

Yeah clearly that's the down side... no doubt I could have been a lot smoother. The damper covers your sins so it prevents you from getting better. On the other hand, it could also prevent you from highsiding into a tree.

Maybe the key is to install the damper but just keep dialing it down until the wiggle is slight and you can work on it?

**CMG241** · 10-11-07, 06:20 AM

Sorry but that was wobble and not tank slap! I went down hard and fast 20 years ago after experiencing tank slap - think machine gun speed w/same sound from steering stop to steering stop.Pretty sure that I broke my wrist before I hit the pavement. Still ugly though, you're lucky.

**Paul_E_D** · 10-11-07, 07:03 AM

Yeah, that was head shake. Like everyone said, using your legs to hold on instead of your arms reduces it, but you can't really eliminate it. It usually appears where you try to change directions without rolling off the throttle. If your arms are tight, you will be forcing the front wheel on a path it would rather not take. The fact that there's little weight on it from acceleration just allows you to fuck it up more.

Bumps plus lean can also cause head shake and tank slappers. Same technique problem, but sometimes the period between bumps is just right and there's little you can do to stop it.

Steering dampers are a good safety blanket for this problem, but are designed to reduce it, not eliminate it all together. Cranking it up to 15 clicks is NOT recommended!!! You'll be missing apexes everywhere and working twice as hard as normal to change directions. At Loudon most people set their dampers very loose, because the bumps aren't bad as far as head shake goes. The most I've ever used was at Beaver Run where a viscious bump in the WOT 5th gear kink would rip the bars from my hands... I ran like 5 clicks.

**xxdcmast** · 10-11-07, 10:26 AM

I get head shake all the time up there. I actually dont mind it too much because as weird as it sounds when Im on my "best" line I will usually head shake really quickly left right left just as Im leaning into the next turn.

Im sure there is a way I can improve and not get this head shake but that will take some more time and thats what next year is for.

**Jayspeed** · 10-11-07, 04:31 PM

My bike has a steering damper that is suppose to get stiffer as your speed increases and softer at slower speeds. An electronic selenoid opens and closes on the damper controlling oil flow. Its no Scotts or Ohlins but better than nothing. If I didn't have a damper, it may have turned out worse. Every other time I've flew through those turns I was mashed againsed my tank and had no problems but that day my legs were so shot. First open session I was about to pit in 1/2 way through, my muscles above my knees in the front of my legs felt like they were both pulled. It was difficult to hold myself off the bike and weighting pegs through out the day. That day I had alot of the brain says "lets go!" and body says "wait for me!"

KB · 10-15-07, 06:37 PM

Originally Posted by Jayspeed

On my last trackday, I had a "oh shit" incident. After turn 7 my speed + reaching a hill brink + weight distribution + steering input = tank slapper. This was my first ever tank slapper and after watching the video it seems like it was nothing but it really felt out of control for a second. You can see the handle bars move and that movement at almost 100mph is alot. I blame my physical condition for I had a tough work day the day before and my legs were shot. I was lazy to not be on the tank at that moment. My Initial thought was, "is my front axle falling off?"
tank slapper

That's normal in that corner is my answer.

KB

**jtaylor719** · 10-15-07, 08:09 PM

Yep, I think everyone gets a little headshake there. Certainly wasn't close to a tankslapper.
I was watching from the T6 stands a couple years ago, saw #9 on a Penguin bike (Duc) passing someone on the outside there. His wobble was so bad it shook him right out of the seat, feet off the pegs! Appeared as though he just screwed on a little throttle and continued with the pass under the treehouse.

I'm still amazed at that move to this day.

**brewmaster** · 10-15-07, 10:10 PM

Originally Posted by Paul_E_D

The most I've ever used was at Beaver Run where a viscious bump in the WOT 5th gear kink would rip the bars from my hands... I ran like 5 clicks.

Yeah I know that turn! The left kink after coming down the hill. Hated the way that felt. I rode my long board down the line after my first day there and realised how rippled the pavement was. Took awhile to get used to it.

Tank slapper at nhis

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