Scary Moments | GTAMotorcycle.com

Scary Moments

-Maverick-

-Maverick-

Well-known member
This first guy is a Rockstar. Imagine sitting back and letting the bike decide your fate?


The guy formerly known as Mladin.
 
Lightcycle said:
Crazy.

Wanna see a thread go multiple pages?

How do you stop a tank slapper?

Aaaaand go...!
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Can we save this for the off season????
 
-Maverick- said:
The crazy part is a lot of these bikes have steering dampeners.

The guy formerly known as Mladin.
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*A part that looks like a steering damper but doesn't have enough damping is installed on a lot of these bikes.

As for the first guy letting the bike decide his fate, I'm not sure if he intentionally let go or if he got shaken off the bars and couldn't get back on.

Second guy was a lesson in how to extend a tank slapper as long as possible.

Related to the tech thread, has any manufacturer incorporated any active controls that sense a shake and try to actively get back under control? Active steering damper control would be easiest and most effective but I haven't heard of that being done. Obviously the IMU could detect the shake and the computer has full control over brakes and throttle. Actually, do any bike systems create brake pressure or do they just release it? Some car systems can create the brake pressure.
 
GreyGhost said:
*A part that looks like a steering damper but doesn't have enough damping is installed on a lot of these bikes.

As for the first guy letting the bike decide his fate, I'm not sure if he intentionally let go or if he got shaken off the bars and couldn't get back on.

Second guy was a lesson in how to extend a tank slapper as long as possible.

Related to the tech thread, has any manufacturer incorporated any active controls that sense a shake and try to actively get back under control? Active steering damper control would be easiest and most effective but I haven't heard of that being done. Obviously the IMU could detect the shake and the computer has full control over brakes and throttle. Actually, do any bike systems create brake pressure or do they just release it? Some car systems can create the brake pressure.
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This.

Suzuki has hill assist on their liter bikes now. If you're riding a liter bike, you're probably not needing anti-stall on hills! What a waste of time and money.

Seeing this video...its a no brainer to use the IMU to sense a tank slapper and settle the bike down electronically. Probably the best use of electronics that could ever be put on a bike.

I guess their problem would be catching every possible variable that causes the wobble. It would require a lot of R&D.

The guy formerly known as Mladin.
 
-Maverick- said:
This.

Suzuki has hill assist on their liter bikes now. If you're riding a liter bike, you're probably not needing anti-stall on hills! What a waste of time and money.

Seeing this video...its a no brainer to use the IMU to sense a tank slapper and settle the bike down electronically. Probably the best use of electronics that could ever be put on a bike.

I guess their problem would be catching every possible variable that causes the wobble. It would require a lot of R&D.

The guy formerly known as Mladin.
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aren't they all still 6 axis imus?

mainimg.jpg

I don't see how it's going to sense the (relatively) minor Roll input a slapper gives you.
 
Evoex said:
aren't they all still 6 axis imus?

mainimg.jpg

I don't see how it's going to sense the (relatively) minor Roll input a slapper gives you.
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You should see it in right-left channel (or maybe yaw). I don't know the actual frequency but look for a big spike in amplitude at 1 Hz or so and you know you are off to the races.
 
Evoex said:
aren't they all still 6 axis imus?

mainimg.jpg

I don't see how it's going to sense the (relatively) minor Roll input a slapper gives you.
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There's still no good consensus amongst anyone as to how to stop a tank slapper.

Some people say roll off, some people say throttle on, lean forward, lean back, take your hands off the bars, lightly grip the bars, etc.

If the solution is to take weight off the front wheel, that requires greater throttle input. Electronic aids like TC cutting throttle is safe enough, but no manufacturer is going to want the liability of the computer choosing to goose the throttle all by itself to lighten the front.
 
Lightcycle said:
There's still no good consensus amongst anyone as to how to stop a tank slapper.

Some people say roll off, some people say throttle on, lean forward, lean back, take your hands off the bars, lightly grip the bars, etc.

If the solution is to take weight off the front wheel, that requires greater throttle input. Electronic aids like TC cutting throttle is safe enough, but no manufacturer is going to want the liability of the computer choosing to goose the throttle all by itself to lighten the front.
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If a bike had control over the damper (afaik none do right now) it could clamp it down quite hard to bleed off the energy.

Edit:
Given an r&d department and adjustable suspension, it may also be possible for the computer to do something the rider never could (eg max front preload, min rear preload to unload front wheel).
 
Lightcycle said:
True.

That is a lot of mechanicals to mitigate one specific scenario though. How often do tank slappers occur?
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True and in practice, it may be safer and easier to have a speed controlled damper that stiffens up as you get moving but relaxes at oarking lot speeds so you don't fall over like an idiot.

Instead of doing analysis to detect a tank slapper, it could also tighten up damper just before you touch the front wheel back down.

See my edit above for a possible solution with no added mechanicals required. Not sure if it would work or not. Some time on a powered roller should quickly let you know if that is a viable path.
 
GreyGhost said:
Given an r&d department and adjustable suspension, it may also be possible for the computer to do something the rider never could (eg max front preload, min rear preload to unload front wheel).
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I don't know about other ESA systems, but BMW's implementation on my bike is sloooow. It takes a good couple of seconds to go from max preload when a passenger gets off to normal ride height again.

All the while, both my feet dangling in the air at a stop... :)

Ask @Jampy00 how long it take the ARH on his bike to do the WheelTrans lowering at a stop?
 
There are lots of types of sensors that could be cheaply fitted to directly measure steering-head oscillations and be linked to an electronically controlled steering damper to increase damping (perhaps magnetically). There was a thread a couple of months ago where Yamaha has been working on full self-steering, which would require similar types of sensors and controls:
www.gtamotorcycle.com

Anti-crash Yamaha

https://www.bennetts.co.uk/bikesocial/news-and-views/news/2023/march/yamaha-anti-crash-bike
www.gtamotorcycle.com www.gtamotorcycle.com
 
I thought most dampers were electronic...they have been on my GSX-R 1000's from K7 onwards. I thought they worked by stiffening steering based on speed, not as Ari describes here. Meaning, the faster I go, the more the damper clamps down, the stiffer my steering gets... it feels that way. That wouldn't explain the tank slappers in this video tho. I'm assuming these bikes have the same system as Suzuki?


The guy formerly known as Mladin.
 
-Maverick- said:
I thought most dampers were electronic...they have been on my GSX-R 1000's from K7 onwards. I thought they worked by stiffening steering based on speed, not as Ari describes here. Meaning, the faster I go, the more the damper clamps down, the stiffer my steering gets... it feels that way. That wouldn't explain the tank slappers in this video tho. I'm assuming these bikes have the same system as Suzuki?


The guy formerly known as Mladin.
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Most dampers will either be linear (added force that doesn't change with force or speed but may be able to be changed manually with a knob) or they may have valving that responds to speed of handlebar movement. Afaik, bike speed is not a factor for the vast majority.
 
GreyGhost said:
True and in practice, it may be safer and easier to have a speed controlled damper that stiffens up as you get moving but relaxes at oarking lot speeds so you don't fall over like an idiot.
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I think Honda's HESD may function this way? I wasn't able to find any good documentation on it just now
 
GreyGhost said:
Most dampers will either be linear (added force that doesn't change with force or speed but may be able to be changed manually with a knob) or they may have valving that responds to speed of handlebar movement. Afaik, bike speed is not a factor for the vast majority.
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I can clearly feel the steering get stiffer on my GSX-R 1000 as speed increases. Suzuki can't be the only manufacturer who's thought of this...the German Gixxer must have stolen this feature too.

Looking at this 600 RR, which comes with a damper, you can see the damper is transferring the wobble through the bike. The steering is stiff as the bike enters the wobble...you can clearly see the energy being transferred through the bike. The alternative is likely much worse:


The guy formerly known as Mladin.
 
GreyGhost said:
If a bike had control over the damper (afaik none do right now) it could clamp it down quite hard to bleed off the energy.

Edit:
Given an r&d department and adjustable suspension, it may also be possible for the computer to do something the rider never could (eg max front preload, min rear preload to unload front wheel).
Click to expand...
gsxr's the damper is speed controlled, more like gear controlled. It can wobble in 1st alot and 2nd less so and in 3rd no chance of a wobble.
 
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