50 kp/h tank slapper

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krrakt

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Holy smokes, I never knew this could happen.

I turned on to Mt.Pleasent from Bloor and went into the left lane to pass a car, there was very little traffic around me.

I took my left hand off of the bar to rest my wrist, I find I'm doing this often since it was shattered in a crash last year.

Then I hit a deep pothole (or manhole), approx. 200m. north of bloor.

The bars literally began to "SLAP" to both sides, I could barely hang on to the right hand bar and the rear brake made the shaking worse.

Trying to get a better grip on the bar, I accedentally blipped the throttle which brought me out of it.

I have had high speed wobbles before, but this was way more scarry. I really thought "I'm Toast".
 
But recovered? Hope you did anyway. I've only had the wobble at high speeds. It works itself out. Turns your underwear brown, but that's about it ;)
 
It happened to me when I was accelerating hard on rough pavement. There's really nothing you can do unless you wait for it to work itself out.
 
Happened to me once when I crossed over railroad tracks at about 80 km/h or so. Wasn't too bad a shake (nowhere near OP's) but scary nonetheless.
 
I got sideswiped once on the dvp and it did this.
 
So this type of wobble is caused by some jolt on the front wheel? Sorry I'm not familiar with this at all...and more importantly what's the correct reaction to it? I assume you don't hit the brakes in a panic?
 
smackenz said:
what does a steering damper really do? other than dampen the steering please. and how does it work?
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It is like a shock absorber without a spring. a cylinder full of oil with a piston inside. The piston has an opening that can be adjusted from small(much dampening) to large (minimal dampening).

One end attached to bike frame and the other to a part that swivels like forks or tripple clamp.

At slow speeds you need very little so you can turn your bars easily, while at high speeds you need more as you never turn the bars very much.and the stiffness of the dampner reduces chances of wabbles
 
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mimico_polak said:
So this type of wobble is caused by some jolt on the front wheel? Sorry I'm not familiar with this at all...and more importantly what's the correct reaction to it? I assume you don't hit the brakes in a panic?
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Right, never hit the brakes, just disenguage the clutch and let it pass.. no brakes or you will crash
 
good to hear u came out alright.

I had samilar experience driving through the metal bridge at Twyn River around the same speed. It was very scary.
 
2 things :

1. STeering damper, it dampens the osscillation (sp?) of it the bars going back and forth... must have for track bikes and I'd say alot of 600's need this now a days too, too twitchy ...

2. My view / way out of it is : Hit the gas ... if you hit the gas you lighten up the front end (insert wheelie here if needed) and by lightening up the front end you remove the need / ability for the front tire to oscillate back and forth since there is little / no weight on it. By applying ANY brakes to it you slow down yes, BUT you increase the load on the front tire... what does this mean ? now you have to fight even harder to bring it under control ... so lesson learned ? hit the gas and you lighten it up and don't have to fight to bring it out of it it naturally goes straight then you let off the throttle slightly and your good ...
 
chiller said:
2 things :

1. STeering damper, it dampens the osscillation (sp?) of it the bars going back and forth... must have for track bikes and I'd say alot of 600's need this now a days too, too twitchy ...

2. My view / way out of it is : Hit the gas ... if you hit the gas you lighten up the front end (insert wheelie here if needed) and by lightening up the front end you remove the need / ability for the front tire to oscillate back and forth since there is little / no weight on it. By applying ANY brakes to it you slow down yes, BUT you increase the load on the front tire... what does this mean ? now you have to fight even harder to bring it under control ... so lesson learned ? hit the gas and you lighten it up and don't have to fight to bring it out of it it naturally goes straight then you let off the throttle slightly and your good ...
Click to expand...

what would happen on a bike with Traction Control??
 
Only real tankslapper I've ever experience was accelerating on rough pavement on my Daytona T595, and that was on surface streets too. (Think it was Finch or Steeles) Probably my scariest motorcycle experience to date. I think I tried to stay/on or increase throttle and maybe that's what got me out of it, but clutching in would have been impossible, it was that violent.
 
kiwi said:
what would happen on a bike with Traction Control??
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Traction control would have no effect - if anything, the system would see the front wheel turning slightly faster than the rear, which is not something it can do anything about. The only "automatic" systems on motorcycles today that can do anything about tankslappers are electronic steering dampers, such as Honda's HESD (which you don't hear much about anymore, but is still a feature on their CBR600RR & CBR1000RR).
 
krrakt said:
Right, never hit the brakes, just disenguage the clutch and let it pass.. no brakes or you will crash
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Better to stay on the gas ( mine was at about 160 after being hit by the car )- came out ok.
 
chiller said:
2 things :

1. STeering damper, it dampens the osscillation (sp?) of it the bars going back and forth... must have for track bikes and I'd say alot of 600's need this now a days too, too twitchy ...

2. My view / way out of it is : Hit the gas ... if you hit the gas you lighten up the front end (insert wheelie here if needed) and by lightening up the front end you remove the need / ability for the front tire to oscillate back and forth since there is little / no weight on it. By applying ANY brakes to it you slow down yes, BUT you increase the load on the front tire... what does this mean ? now you have to fight even harder to bring it under control ... so lesson learned ? hit the gas and you lighten it up and don't have to fight to bring it out of it it naturally goes straight then you let off the throttle slightly and your good ...
Click to expand...


Not quite. Acceleration speeds up the gyroscopic effect on the front wheel. The faster the wheel spins the more force that is generated causing the wheel to right itself.
Be glad you weren’t maxed out like this poor sod.

[video=youtube;V1W5HN40bpw]http://www.youtube.com/watch?v=V1W5HN40bpw[/video]

This is the Arrow damper that was on my wife’s M600

DSC00140.JPG
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