Stiff vs. flexible sidewall

CKR47

Member
Obviously the more internal prep will "usually" soften the sidewall yielding a softer (lower) spring rate. I believe that I read that this will give the tire more grip. However, when talking about conventional coil springs, a stiffer spring will give that corner of the car more grip, since the "stiff spring gets the weight". Why wouldn't these analogies be the same?
 

XXX#40

2A supporter
Because the spring doesn't make contact with the ground, nor does it flex and roll over when pressure is applied
 

CKR47

Member
Okay so both theories are correct? And in the sense that the tire is a spring but it rolls over and makes more contact with the track, you are actually getting more grip? Is that right?
 

XXX#40

2A supporter
Okay so both theories are correct? And in the sense that the tire is a spring but it rolls over and makes more contact with the track, you are actually getting more grip? Is that right?
more grip when that type of tire is needed less when its not
 

paulkish

old fart
Okay so both theories are correct? And in the sense that the tire is a spring but it rolls over and makes more contact with the track, you are actually getting more grip? Is that right?

You need a better understanding about what springs do racing oval. It doesn't matter if both theories are correct or not it's about using how springs function to do what is needed at all places around the track.

Here's a quick run down on what springs do for you. Most of my theory follows in this quick reply before I head out to the track. Engineers and you via the web can calculate spring rates to your hearts content. It's about how you use the springs no matter if it's the chassis or tires that counts.

1. Springs set total potential chassis travel at all four corners. Stiffer springs less potential chassis travel.
2. Springs set ride heights.
3. Softer springs per equal work input take longer to operate if they increase chassis travel.
4. When you have multiple springs, which you do, the softest spring operates first both compressing and releasing.


That's all springs do racing oval weather there chassis, real added on springs or tires.


Now to offer something per what I see about your thought process. If I'm reading you correctly your next going to be thinking about having a stiffer sidewall on the RR tire and a softer sidewall on the LR tire? ... :)

Have you heard of putting bb's inside the tire while it's rolling to keep prep from running down/up on the sidewall? If I'm wrong about the bb's someone will surely correct me. ... :)
 

CKR47

Member
Thanks for the elaborate response Paulkish... I'm basically trying to wrap my head around what the effect will be of having a softer spring (tire) vs. stiffer spring (tire). If you have a thinner cut, more edge to the cut, less prep on the sidewall, harder compound, you will have a stiffer spring. When you want this stiffer spring and where is the tough part. Also, the situations in which you obtain a "stiffer spring"... (i.e. wanting thin vs. thick cut or stiff sidewall vs. rolling sidewall)
 

paulkish

old fart
Thanks for the elaborate response Paulkish... I'm basically trying to wrap my head around what the effect will be of having a softer spring (tire) vs. stiffer spring (tire). If you have a thinner cut, more edge to the cut, less prep on the sidewall, harder compound, you will have a stiffer spring. When you want this stiffer spring and where is the tough part. Also, the situations in which you obtain a "stiffer spring"... (i.e. wanting thin vs. thick cut or stiff sidewall vs. rolling sidewall)

You need a little more basic understand of how things work.

Tires applying weight are simple. They apply weight per air pressure and contact area.

The rest is grip and how your directing weight from your cog( center of gravity) as a general reference and proportionally from other places.

A softer verses stiffer sidewall changes how weight is directed at, around, over, under, front of or behind your contact patch.

The same with ride height. Weather you change it in your basic setup before you hit the track or consider how it changes per how your springs operate it's doing the same as in the sentence above. Setup is all about how weight is directed at, around, over, under, front of or behind all tire contact patches at all places around the track to make the tire want to roll in the direction you want to go. Problems are all the result of conflict for control of direction by your tires and you having to force tires to roll where you want to go.

It's not about how rolling the sidewall over on a tire effects grip or the contact patch, so long as there is grip available. It's about how rolling the sidewall over at a particular place on the track either makes that tire stronger in it's ability to roll in it's natural direction AND that's also the direction you want to go. If you roll a sidewall over and it becomes stronger with its ability to roll straight you have to add more input from somewhere else to make it go where you want to go, DEPENDING ON YOUR LOCATION ON THE TRACK THAT CAN BE EITHER GOOD OR BAD.

In general when your racing you want to do your turning and slowing down going up hill(up the bank of the track). If you have grip available the added conflict you create for control of direction by rolling a sidewall over more may be a good thing if you already need to slow and turn. That's because the conflict can be used to both assist you to slow down to a needed speed and help turn you so you can roll an arc through a portion of the corner at a constant speed maintaining all important momentum.

I may have confused you when you read this or it may help you understand and be able to see better in your mind how changing setup does effect how your tires are operated. The rest is all about putting a good baseline setup on the track and then fixing on track problems. Those who give setup advice on here have the experience working with "good" baseline setups and understand what would need done to fix on track problems. You don't need any of my theory to fix on track problems. You only need to know what to do to generally fix on track problems when you have put a good, decent, acceptable, generally thought of as pretty good and ok, baseline setup initially on the track.

And all of the above is only IMHO and ain't necessairly right anyway. ... :)


oh... if you want to do your turning and slowing down going up hill, then wouldn't you want to complete your turning do your accelerating going down hill?

... and another real world racing thing to know. If you try to complete your turning and acceleration going 'uphill', you will push. And the push I just described is different then 4 wheel drifting up and across the track coming off a turn. ... just a little more to confuse??? ... :)
 
Last edited:

OBR

Member
You need a little more basic understand of how things work.

Tires applying weight are simple. They apply weight per air pressure and contact area.

The rest is grip and how your directing weight from your cog( center of gravity) as a general reference and proportionally from other places.

A softer verses stiffer sidewall changes how weight is directed at, around, over, under, front of or behind your contact patch.

The same with ride height. Weather you change it in your basic setup before you hit the track or consider how it changes per how your springs operate it's doing the same as in the sentence above. Setup is all about how weight is directed at, around, over, under, front of or behind all tire contact patches at all places around the track to make the tire want to roll in the direction you want to go. Problems are all the result of conflict for control of direction by your tires and you having to force tires to roll where you want to go.

It's not about how rolling the sidewall over on a tire effects grip or the contact patch, so long as there is grip available. It's about how rolling the sidewall over at a particular place on the track either makes that tire stronger in it's ability to roll in it's natural direction AND that's also the direction you want to go. If you roll a sidewall over and it becomes stronger with its ability to roll straight you have to add more input from somewhere else to make it go where you want to go, DEPENDING ON YOUR LOCATION ON THE TRACK THAT CAN BE EITHER GOOD OR BAD.

In general when your racing you want to do your turning and slowing down going up hill(up the bank of the track). If you have grip available the added conflict you create for control of direction by rolling a sidewall over more may be a good thing if you already need to slow and turn. That's because the conflict can be used to both assist you to slow down to a needed speed and help turn you so you can roll an arc through a portion of the corner at a constant speed maintaining all important momentum.

I may have confused you when you read this or it may help you understand and be able to see better in your mind how changing setup does effect how your tires are operated. The rest is all about putting a good baseline setup on the track and then fixing on track problems. Those who give setup advice on here have the experience working with "good" baseline setups and understand what would need done to fix on track problems. You don't need any of my theory to fix on track problems. You only need to know what to do to generally fix on track problems when you have put a good, decent, acceptable, generally thought of as pretty good and ok, baseline setup initially on the track.

And all of the above is only IMHO and ain't necessairly right anyway. ... :)


oh... if you want to do your turning and slowing down going up hill, then wouldn't you want to complete your turning do your accelerating going down hill?

... and another real world racing thing to know. If you try to complete your turning and acceleration going 'uphill', you will push. And the push I just described is different then 4 wheel drifting up and across the track coming off a turn. ... just a little more to confuse??? ... :)
Very good read!
 
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