Track Tac

Brain exercise , long bench racing post.

paulkish said:
That is only true if you have the same amount of soldiers with equal ability carrying the weight.

Your formula math example using the chassis and tires from the COG, means you have multiple soldiers of varying ability.
The result is your comparing apples and oranges to define how a spring works.
Click to expand...
Say you have a box supported by a soldier at each corner.
All are capable of carrying their share of the load, but the bastard on the rf is loafing and not carrying his share.

Where does the part of the load that he is not carrying go?
Now replace that guy with another willing to carry the load, but not capable.
Where does the extra load go?

Throw another 50# on the right side of the box.
Where does that load go?
 
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95 shaw said:
Say you have a box supported by a soldier at each corner.
All are capable of carrying their share of the load, but the bastard on the rf is loafing and not carrying his share.

Where does the part of the load that he is not carrying go?
Click to expand...
Depends on available grip and acceleration. ... :)

... or it depends on where available grip and acceleration cause it to go.

All springs and everything else on the chassis do is direct the on track forces moving the weight you have available, to do what you need done.
 
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95 shaw said:
Say you have a box supported by a soldier at each corner.
All are capable of carrying their share of the load, but the bastard on the rf is loafing and not carrying his share.

Where does the part of the load that he is not carrying go?
Now replace that guy with another willing to carry the load, but not capable.
Where does the extra load go?

Throw another 50# on the right side of the box.
Where does that load go?
Click to expand...
I will go out on a Limb and say .
Mostly to the poor soldiers on the Left front and right rear .
Scenario #2 Mostly on the right 2 soldiers .
 
flattop1 said:
I will go out on a Limb and say .
Mostly to the poor soldiers on the Left front and right rear .
Scenario #2 Mostly on the right 2 soldiers .
Click to expand...
2nd scenario, RF is already not capable of carrying the load before the additional weight, so, same as the first. Add 50# to the right side if the box. Rr mostly, with a little spread to the other 2. Least to the lr.
Changing to a soldier not capable does not better the distribution. Adding weight to the pair exasperated the problem.


I'm not sure we need to demand I am wrong, then say the same thing I am saying, in a convoluted way.

Not really productive at all.
 
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If we redistribute the load, so all are capable, even though one is not carrying as much, things will likely go better.
 
I'm not sure we need to demand I am wrong, then say the same thing I am saying, in a convoluted way.

Not really productive at all.
[/QUOTE]

Not aimed at you. Flattop
 
95 shaw said:
Say you have a box supported by a soldier at each corner.
All are capable of carrying their share of the load, but the bastard on the rf is loafing and not carrying his share.

Where does the part of the load that he is not carrying go?
Now replace that guy with another willing to carry the load, but not capable.
Where does the extra load go?

Throw another 50# on the right side of the box.
Where does that load go?
Click to expand...

I probably could have written the last part of this better to make the example I was trying for better for what I am going to say now. Wouldn't change the outcome if we transferred 50# from the left edge of the box to the right.

In Paul's example, the weight is distributed perfectly and all soldiers are willing and capable.
This is only going to be true for short sections of the lap.
The rest of the lap, distribution is going to be unequal.

The first scenario above, all are capable, but not willing, resulting in uneven distribution. Moving some weight around to make the slacker think he is doing less than his share would help everyone.
Maybe a change in preload?

Swapping to the guy willing. But less capable, more preload is not going to make his job any easier, like too soft a spring.

In the scenario I listed above, even more weight is having to be carried by the rr.

Just some thoughts.
 
I was going to say there's probably not more then 3/4" of deflection in the chassis .
Then remember seeing the left frt on our Dino Kart up in the air a good 2-3 inches and the Left rear on the Phenom up 1-2 inches .
 
I was think in terms of the chassis
As a spring . A stiff spring .
Then reread page 1 .
Found this .
The strongest geometric shape in terms of deflection in both compression and extension is a triangle.

Now add 3 dimensions instead of only 2.
Strength in a specific plane is defined by 3 points of the triangle in a single plane.

Deflection is greater in planes otherwise than those 3 points.
 
Though you were talking about springs.
I was and the soldiers were about springs.

I have no idea why you brought in weight distribution.
I was into and thinking about weight projection, chassis operation and the working of springs.

The soldiers and their amount in my mind were coils on a spring.
You can do the same work with more or less soldiers supporting the same weight.

I was trying somehow to relate how supporting soldiers are used in different numbers and abilities per needs to your initial thoughts of the chassis being a complex spring.

When you brought in weight distribution I got totally lost and was trying to get away from this thread.
 
flattop1 said:
I was think in terms of the chassis
As a spring . A stiff spring .
Then reread page 1 .
Found this .
The strongest geometric shape in terms of deflection in both compression and extension is a triangle.

Now add 3 dimensions instead of only 2.
Strength in a specific plane is defined by 3 points of the triangle in a single plane.

Deflection is greater in planes otherwise than those 3 points.
Click to expand...
So the spring is somewhat directional, or regional depending on the angle between the planes.

The areas unsupported bearing a load are easy. Say the left frame rail behind the seat bar and nerf spud.

The complex shapes take more thought.

I've always thought a rigid space frame and suspension, although more complex from component view, were easier to follow as far as springs and their effects were.

Wheel rates vs spring rates can throw you for a loop.
 
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On the Length vs stiffness factor .
A kart chassis doesn't have any straight tubes over 20 inches .
Before a bend or weldment .
With a max total Length with bends 40" .
If you deflect the Lr up in the vertical plane . That force travels too the half moon seat bend , then the torsional
Twisting Lifting force should the directed at the Lft frt.
... On that tube alone not considering any others .
 
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Correct, until the front seat bar.

Series and parallel springs in play.

Everyone gets caught up in loading the springs.
Perhaps the biggest benefit is from unloading the spring.

As in compression, the spring must travel to unload. A softer spring travels further to unload the same weight as a stiffer spring.
In theory, the left rear should be at its maximum load on the scales. Only counter steering should ever add more load.
The soft lr keeps load on the tire for more of the travel.
The right front should have near the minimum weight it will ever see on the scales.

The left front should unload. If it does not, it is because of the travel from the Rf and lr.
 
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For spring adjusting purposes, we can largely consider the front seat bar as the dividing point for spring rates.
Not always, but mostly
 
I had a conversation with someone yesterday. I'm not saying they're right or wrong. A lot of what we discussed was focused more around higher HP stuff. But, more as to why current stock karts don't work as well for high HP now.

They said that essentially yes the chassis is a big spring, and you can have it soft or stiff. That's the problem with most modern chassis. Chasing speed with a stiff chassis is hard because there is no middle ground. He also said that changing bars, and specifically mentioned where they connect and this and that to alter how stiff it is, but he said the changes were VERY minimal.

I think this has been the strive of most new chassis on the market within the last 5 years or so. Trying to keep it "just" stiff enough to carry roll speed. Since Roll speed and grip don't usually work together well. But, soft enough to give it enough grip to work on lots of surfaces and be forgiving when the either the driver or the tires aren't at 100%.

I think we've come to a time where it's more of a fine tuning situation with chassis manufacturers for certain track types. He and I had a conversation about how modern chassis use lateral weight transfer to function properly. Fine tuning that through timing, and duration is how you get a chassis that can carry roll speed, and still have grip. I think for the next few years until we see a dramatic change in how chassis are designed to work we'll see a continuation of fine tuning from manufacturers. He said he was working on a new chassis again himself, but of course couldn't give any details on it. He's had some different designs over the years that were fast. So I'm looking forward to seeing if he gets it finished for next year or not.

Prior to this conversation the idea of this very thing about moving bars, and how each bar specifically interacted with the next is what lead me to post this. Trying to get a better understanding of just how the bars work together to produce a chassis that is fast. But, more so how others came to arrange the bars in such a way, like what lead them down this design road.
 
As I said before, it seems simpler to be working with 4 removable springs and make adjustments from there.

Nascar teams use pull down rigs and 7 post arrangements to try to simulate what happens to individual wheel loads around the track to envision what the next change should do.
I'm trying to imagine such a rig for karts, and it may exist. But changes are largely cut and try.
So having an understanding of what you want from a change, and how you wish to accomplish it is very important.

With the 4 springs, there is a nearly infinite combination of static wheel weights and springs that can be made to work, some better than others. Kart chassis are no different.
 
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