50 kp/h tank slapper

[absolute]

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i had a tank slapper before too, left lane left tire track on lakeshore westbound approaching the gardiner, hit the rail road tracks at around 70ish.

scared the poop out of me lol. i just let it go, no brakes no gas and it recovered itself pretty fast like within a second.

 

[casacrow]

I believe most of these slappers are likely caused by too tight of a grip on the bars. They are there to receive your inputs, not to hold you up.

 

[Nofear]

[video=vimeo;3737864]https://vimeo.com/3737864[/video]

WTF happend wrong here???

He did a stoppie and probably put all his weight on the handlebars instead of gripping the tank. That mixed with a crappy parking lot surface and a bit of uneven input to the bike upset it.

Bet that icon vest offered soooo much "protection" :lol:

 

[onecartel]

Right, never hit the brakes, just disenguage the clutch and let it pass.. no brakes or you will crash

Rolling on the throttle is usually the best solution for a slapper.

 

[Wheelieboy]

He did a stoppie and probably put all his weight on the handlebars instead of gripping the tank. That mixed with a crappy parking lot surface and a bit of uneven input to the bike upset it.

Bet that icon vest offered soooo much "protection" :lol:

Looked like the front tire locked up, handlebar turned slightly, let go of brake, bike goes in direction of turned handlebar, BOOM

 

[kanabis]

Looked like the front tire locked up, handlebar turned slightly, let go of brake, bike goes in direction of turned handlebar, BOOM

I thought he pressed the front brake to hard and leaned to one side to much and BOOM! there goes the wobble...

 

[krrakt]

I believe most of these slappers are likely caused by too tight of a grip on the bars. They are there to receive your inputs, not to hold you up.

Really? I've never heard this. I was barely holding ONE handelbar, if there was weight on it wouldn't the bike just go around in circles?

 

[eljay]

It's caused by some harmonic oscillation, growing in amplitude. Think of the wiggly shopping cart wheel. It's the same thing. It can only be stopped by disruption... I'm too much of a noob on a bike to know how to do that safely. Both braking or acceleration could do it, but probably depends on the circumstances.

I believe most of these slappers are likely caused by too tight of a grip on the bars. They are there to receive your inputs, not to hold you up.

 

[casacrow]

It's caused by some harmonic oscillation, growing in amplitude. Think of the wiggly shopping cart wheel. It's the same thing. It can only be stopped by disruption... I'm too much of a noob on a bike to know how to do that safely. Both braking or acceleration could do it, but probably depends on the circumstances.

Sure, you could hang on tight in an attempt at distruption, and transfer that energy through you, to the rear of the bike. Not a good situation.

 

[krrakt]

It's caused by some harmonic oscillation, growing in amplitude. Think of the wiggly shopping cart wheel. It's the same thing. It can only be stopped by disruption... I'm too much of a noob on a bike to know how to do that safely. Both braking or acceleration could do it, but probably depends on the circumstances.

Braking is NEVER a solution to a speed wabble! A crash is guaranteed if you use the brakes during one, especially the front.

Brakes may stop the oscillation but the tire direction/position can't be foreseen and it most likelly it will NOT be pointed straight foreward when the oscillation stops.

 

[LoneRonin]

Rolling on the throttle is usually the best solution for a slapper.

pretty much. I think the only reason people get scared is they're already going fast and don't think going faster will actually be safer...

 

[Acadian1974]

It's hard to find data on dealing with this scenario that's not anecdotal, but the bits of info that are available seem to indicate that weight transfer to the rear of the bike combined with too much firm input by the rider through the bars increases its likelihood. There also seems to be agreement that accelerating is not right course of action, rather you should shift your weight forward while maintaining a relaxed grip on the bars as you gradually decelerate (with one article proposing using the front brake in addition to those steps to disrupt the harmonics). This seems sensible, as removing the cause of a problem is usually the best way to deal with a problem, in this case the lightening of the front end, accelerating would only exacerbate it.

http://www.msgroup.org/Tip.aspx?Num=190
http://www.timeshighereducation.co.uk/story.asp?storycode=167234
http://www.sportrider.com/ride/rss/113_0206_motorcycle_tankslappers/index.html
http://faq.f650.com/FAQs/RidingTipsFAQ.htm#What do I do in the event a Tank Slapper happens to me

 

[SkyRider]

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]

actually in this video the bike's rear shock had a malfunction. it's not your traditional tank slapper. these IOM bikes have the best steering dampers money can buy so normally they would not tank slap like that.

 

[murf]

It's hard to find data on dealing with this scenario that's not anecdotal, but the bits of info that are available seem to indicate that weight transfer to the rear of the bike combined with too much firm input by the rider through the bars increases its likelihood. There also seems to be agreement that accelerating is not right course of action, rather you should shift your weight forward while maintaining a relaxed grip on the bars as you gradually decelerate (with one article proposing using the front brake in addition to those steps to disrupt the harmonics). This seems sensible, as removing the cause of a problem is usually the best way to deal with a problem, in this case the lightening of the front end, accelerating would only exacerbate it.

http://www.msgroup.org/Tip.aspx?Num=190
http://www.timeshighereducation.co.uk/story.asp?storycode=167234
http://www.sportrider.com/ride/rss/113_0206_motorcycle_tankslappers/index.html
http://faq.f650.com/FAQs/RidingTipsFAQ.htm#What do I do in the event a Tank Slapper happens to me

After having dozens of these usually at full throttle I always keep it pegged. Works for me.

 

[SkyRider]

It's hard to find data on dealing with this scenario that's not anecdotal, but the bits of info that are available seem to indicate that weight transfer to the rear of the bike combined with too much firm input by the rider through the bars increases its likelihood.

grrrr no. weight transfer and death grip doesn't cause tank slapper. usually tank slapper happens when:

1. hard acceleration out of a corner, front wheel lifts up an inch or two, rider upshift, front wheel touches down crooked.

2. touching down a wheelie with front wheel crooked

3. hitting a deep pot hole, causing front wheel to go crooked.

some people freakout during tank slap, they brake and or close throttle, causing weight transfer to the front, unbalance the bike even more until the point of no return. crash

staying calm during tank slap and maintain constant throttle or accelerate, takes weight off the front and tank slapper will stop.

suggesting shifting your weight to the front is just wrong lol. no sure where you get that idea from.

front brake during tank slapper? LMAO.

 

[Acadian1974]

suggesting shifting your weight to the front is just wrong lol. no sure where you get that idea from.

front brake during tank slapper? LMAO.

Once again, the published data seems to contradict your claim... but don't let that stop you from believing otherwise if it makes you feel better.

http://www.timeshighereducation.co.uk/story.asp?storycode=167234
http://www.msgroup.org/Tip.aspx?Num=190
http://www.sportrider.com/ride/rss/113_0206_motorcycle_tankslappers/index.html

 

[SkyRider]

Once again, the published data seems to contradict your claim... but don't let that stop you from believing otherwise if it makes you feel better.

http://www.timeshighereducation.co.uk/story.asp?storycode=167234
http://www.msgroup.org/Tip.aspx?Num=190
http://www.sportrider.com/ride/rss/113_0206_motorcycle_tankslappers/index.html

couple of website's "anecdotal' claims doesn't make it fact. you can ask any track rider on gtam and they can answer you.

 

[kiwi]

I think tc only kicks in if the rear slides, so i don't think it would do anything.

I know the TC on some BMWs will not allow you to wheelie... So this would reduce the chance of a tank slapper occurring from a small wheelie

 

[dricked]

Why would you ignore peoples first hand experience? Have you ever had a "tank slapper"? Try grabbing your front brake and shifting your weight foreward under these conditions, I bet you won't like it.

 

[onecartel]

Once again, the published data seems to contradict your claim... but don't let that stop you from believing otherwise if it makes you feel better.

http://www.timeshighereducation.co.uk/story.asp?storycode=167234
http://www.msgroup.org/Tip.aspx?Num=190
http://www.sportrider.com/ride/rss/113_0206_motorcycle_tankslappers/index.html

It appears Acadian's referring to how to prevent a tankslapper and SkyRider is suggesting how to recover once you're already in a tankslap situation. You're both right.

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