Cross VS Stagger

jaymancds

Premium User
Another thread got me thinking, so I figured I would ask. Is stagger necessary?

For me (so far) every set of tires I have had are 34" right side, 33" LR, 32.5" LF out of the box. Obviously this varies just a hair, but in 4 sets this year they have all been close enough to the nominal measurements. So that is 1.5" Front stagger and 1" rear. Could you adjust the kart in such a way that these "unmolested" staggers could be viable? And I know, at some tracks they already are, but at my local 1/8th mile I typically aim for 1.5" front and rear.

Could it be possible to adjust the kart to where you could theoretically never have to set staggers?
 

Ted Hamilton

Design Drafter / Racer
The purpose of stagger is to introduce an inherent yaw to the left. If you kart was responsive enough steering that it didn't need help, no stagger would be neccesary. Sprint karts turn in both directions "equally" well with zero stagger. If your VCg was hign enough to unweight LR enough, that alone would create the yaw effect. I would think on a grippy dirt track, you could get by with little stagger so long as other compensations were made. On a dry slick track, you'd probably need it. So since your scenario is within that range, I'd think you could run "out of the box" and find a setup that would "work," but I doubt it would be as fast as someone who optimized ALL the factors. Those people are rare, but they're the winners.
 

95 shaw

Premium User
There is a reason you do not see sprint chassis being competitive at dirt ovals. When I started racing, there were very few lto chassis.

The philosophy to make best use of stagger has evolved over the years. Looking at the wheel weight numbers, you should see the trend is more toward loading the RR tire to make stagger effective, vs unloading the LR tire to allow chassis to turn. This also makes use of bothe rear tires in the center of corner for lateral grip vs a single overloaded RR tire. This is where a sprint chassis loses major ground to a properly adjusted modern lto chassis. Even lto chassis from a few years ago give up too much corner speed to be competative.
Since less overall grip is needed to go down the straights, and one tire on a solid staggered axle must slip, it only make sense that the least loaded tire would do that slipping.
Stagger is only totally effective for a short distance in any corner. So, adjustments can be made to make use of the stagger you have. Likely will need to be more than just cross.
Since the use of prep to adjust the grip characteristics of the tire is so prevalent, adjusting the physical characteristics of the tire should not be a stretch.
 
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alvin l nunley

Premium User
Every time I see discussions of LTO racing ideas start running through my head.
Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn. With stagger, why would you need to do that , on anI LTO track, with stagger, why would you need to do that?
 

95 shaw

Premium User
Every time I see discussions of LTO racing ideas start running through my head.
Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn. With stagger, why would you need to do that , on anI LTO track, with stagger, why would you need to do that?
Weight still transfers. The place where you need the weight changes based on chassis design.
This is evident by the static weights and percentages for modern lto chassis vs sprint chassis, or even lto chassis from not that many years ago.

Also marked by seat placement compared to a sprint chassis.
 
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95 shaw

Premium User
I started this several years ago, before being disrupted by a couple of members.

Maybe a revist is in order.


 

alvin l nunley

Premium User
I started this several years ago, before being disrupted by a couple of members.

Maybe a revist is in order.


Don't use the computer, do it all by hand, if you have the ability, why not? Only thing is, While you're trying to figure out what a 1% change in nose Weights do, I'll have calculated 10 different scenarios in The Same amount of time. The formulas in my spreadsheets are the exact same formulas you use on your piece of paper. Maybe you use a calculator, is that right?
 

95 shaw

Premium User
Don't use the computer, do it all by hand, if you have the ability, why not? Only thing is, While you're trying to figure out what a 1% change in nose Weights do, I'll have calculated 10 different scenarios in The Same amount of time. The formulas in my spreadsheets are the exact same formulas you use on your piece of paper. Maybe you use a calculator, is that right?
The reason to do it by hand is obvious by just reading your posts.
You can generate reams of numbers, but have no clue where those numbers come from, or what they mean. Being able to show your work is important. A calculator is fine, just write down what you are doing.
If you make a simple mistake entering the initial numbers in your spreadsheet, you will not see the mistake, and have just made a whole list based on incorrect numbers.
The number are to give you an idea of what is happening. Most will find that after they get a handle on what weight goes where, there will be no need to generate those numbers at all.
 

paulkish

old fart
. I would think on a grippy dirt track, you could get by with little stagger so long as other compensations were made. On a dry slick track, you'd probably need it.

That is totally backwards.
Grip track more stagger usually needed to free it up and slick less stagger to tighten it up.
==========================

If your VCg was hign enough to unweight LR enough, that alone would create the yaw effect.

.... what? He is running oval not sprint.
"yaw" How can unloading the LR cause "yaw"? With stagger it's exactly the opposite you use your LR(inside rear) as an anchor/rudder to give the RR(outside rear) something to rotate/yaw around. To have "yaw" you need a "yaw axis" which is the LR.
Unloading the LR is going to happen because your turning.
The more you loose in the ability of the LR to give you a "yaw axis" the more your likely to need to gain turning ability from your front tires.
 

95 shaw

Premium User
I started this several years ago, before being disrupted by a couple of members.

Maybe a revist is in order.



When you think you have a handle on this, get a chassis troubleshooting guide, such as no goats, etc, and go through suggested adjustments.
If you can see how an adjustment suggested would make sense in the situation, you are on the right trail. If you cannot see how that will help, you are missing one or more details and need more research.
 

RCJ

Member
No ,stagger needs to match the radius of the track. Where as c/w is dealing with how the wieght is transferred
 

95 shaw

Premium User
No ,stagger needs to match the radius of the track. Where as c/w is dealing with how the wieght is transferred
Stagger needs to match, but know only going to match for a short distance in corner. Where that happens, and how weight transfers before, and after is the key.


Also makes cross, and spring rate/ chassis design, as well as tire selection and prep important for the entire setup.
Baselines just give you a starting point, a place to start from, or return to, when you figure you are lost.
 

paulkish

old fart
I've said once and maybe a thousand times on here.

Quoting me ... :) : "ya put yer best baseline guess on the track and then fix on track problems.".
 

Festus

New member
There is a reason you do not see sprint chassis being competitive at dirt ovals. When I started racing, there were very few lto chassis.

The philosophy to make best use of stagger has evolved over the years. Looking at the wheel weight numbers, you should see the trend is more toward loading the RR tire to make stagger effective, vs unloading the LR tire to allow chassis to turn. This also makes use of bothe rear tires in the center of corner for lateral grip vs a single overloaded RR tire. This is where a sprint chassis loses major ground to a properly adjusted modern lto chassis. Even lto chassis from a few years ago give up too much corner speed to be competative.
Since less overall grip is needed to go down the straights, and one tire on a solid staggered axle must slip, it only make sense that the least loaded tire would do that slipping.
Stagger is only totally effective for a short distance in any corner. So, adjustments can be made to make use of the stagger you have. Likely will need to be more than just cross.
Since the use of prep to adjust the grip characteristics of the tire is so prevalent, adjusting the physical characteristics of the tire should not be a stretch.
Very interesting. So Would that be shifting few percent from left side to right?
 

alvin l nunley

Premium User
Another thread got me thinking, so I figured I would ask. Is stagger necessary?
This is really easy to do if you have a CAD/CAM computer program (which I do) and some free time.

Draw 2 circles, spaced 40 inches apart, around the same center point. Obviously the circles are different lengths. If it takes exactly 20 turns of the 34" wheel to go around the outside circle it would take less Circumferenceto go around the inside circleThe same number of turns. The math is pretty simple to calculate how much smaller a tire needs to be to go around the inside circle the same 20 turns. This is stagger, the difference in circumference between the outside tire and the inside tire.

If the inside tire is bigger or smaller in circumference than the calculations indicate, and the 2 tires are connected to each other, the inside tire is either going to be spinning faster or slower than the outside tire. A spinning/Sliding tire has less traction than a rolling tire. Plus it uses up horsepower.

It's not an easy task to find the perfect stagger, driving lines change, track conditions change etc. etc. The more weight you have on the tire, the more critical the proper stagger becomes. Still, the closer you get, the faster you go.
 

paulkish

old fart
Al asked: "Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn. With stagger, why would you need to do that"

It's not a matter of weight leaving the inside rear Al, it's about the ">>>FACT<<<" in a turn it ">>>always will<<<" leave the inside rear.

I think it is you Al who often proposes a rolling tire offers the least resistance.

Since even with stagger because turns are not perfectly round, except for where stagger exactly matches up to the radius of the track one tire or both tires have to slip and offer rolling resistance.

Perfection then becomes about how you match the amount of unloading of the inside rear per stagger, tire grip, track grip and how your racing is using track banking according to weather your slowing down maintaining speed or accelerating, to use your inside rear tire to accomplish something needed. In a nutshell if your using the resistance between the inside rear tire and the track to provide something you need then it can not at anytime be scrubbing off speed.

An example is when you're on a straight with more then enough available hp to slip either or both rear tires, you may be gaining your acceleration strictly from the INSIDE REAR smaller tire and slipping your OUTSIDE REAR tire.

Why would you even want to do that, you might ask Al?

The reason would be to accelerate using your sudo low gear off the smaller INSIDE REAR tire and at the same time also be putting preload on your INSIDE REAR tire for entry to the next turn.

Any time you use stagger outside of a perfect circle it's use will as you correctly often say on here: ">>>ALWAYS<<<" offer resistance.
Yes you are absolutely correct Al about stagger offering resistance on the straights.

Butt Al it will only scrub off speed depending on a lack of available hp or not being in a position on the track where it is necessary to reduce built up momentum.

There's a difference Al between scrubbing off speed and reducing acceleration.
Yes I expect understanding the difference to be difficult.

Each Al have their own fixes or adjustments to minimum each.
THEY ARE TWO SEPERATE THINGS. period


Speed because of stagger on the straights is ONLY scrubbed off because of excessive use of one or the other rear tire. period.
The fix depending on available hp is to either increase or decrease the grip at one or both rear tires.
Which rear tire or both you need to fix depends again on available hp AND your ability to change how both or one rear tire is gripping.
It's all about reducing any conflict or fight for acceleration between your two rear tires at all places around the track where acceleration is possible.
Beyond that it's about reducing any conflict for control of direction between your front and rear tires.

Perfection/balance is all four tires rolling and turning while accelerating, decelerating and maintaining speed in the direction you want to go.

The only thing which makes a LTO karts faster in turns then sprint karts is their ability to reduce the need for front tires to do "ALL" turning.
The only thing which makes sprint karts faster when going straight then LTO karts is they do not need to slip a tire when going "STRAIGHT".

ANY time either a sprint kart or a LTO kart is NOT going straight, except for when stagger on a LTO matches exactly to the radius of a turn, one of the rear tires or both MUST slip.

... well right or wrong, that was fun to write
 

paulkish

old fart
Al stated: "Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn.

No it does NOT need to unload the inside rear to turn.
Your into only believing if facts are presented.
Show me one fact Al stating the inside rear must be unloaded to be able to via front end weight jacking.
I stated a fact that because your turning and lateral acceleration is involved weight will unload from the inside rear.
But it does not have to unless you give a reason why it must be done. ... :)

It needs to unload the inside rear to turn efficiently Al.

Unload the inside rear too much or too less and you reduce speed in the turn or exiting the turn.
 

Festus

New member
Al asked: "Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn. With stagger, why would you need to do that"

It's not a matter of weight leaving the inside rear Al, it's about the ">>>FACT<<<" in a turn it ">>>always will<<<" leave the inside rear.

I think it is you Al who often proposes a rolling tire offers the least resistance.

Since even with stagger because turns are not perfectly round, except for where stagger exactly matches up to the radius of the track one tire or both tires have to slip and offer rolling resistance.

Perfection then becomes about how you match the amount of unloading of the inside rear per stagger, tire grip, track grip and how your racing is using track banking according to weather your slowing down maintaining speed or accelerating, to use your inside rear tire to accomplish something needed. In a nutshell if your using the resistance between the inside rear tire and the track to provide something you need then it can not at anytime be scrubbing off speed.

An example is when you're on a straight with more then enough available hp to slip either or both rear tires, you may be gaining your acceleration strictly from the INSIDE REAR smaller tire and slipping your OUTSIDE REAR tire.

Why would you even want to do that, you might ask Al?

The reason would be to accelerate using your sudo low gear off the smaller INSIDE REAR tire and at the same time also be putting preload on your INSIDE REAR tire for entry to the next turn.

Any time you use stagger outside of a perfect circle it's use will as you correctly often say on here: ">>>ALWAYS<<<" offer resistance.
Yes you are absolutely correct Al about stagger offering resistance on the straights.

Butt Al it will only scrub off speed depending on a lack of available hp or not being in a position on the track where it is necessary to reduce built up momentum.

There's a difference Al between scrubbing off speed and reducing acceleration.
Yes I expect understanding the difference to be difficult.

Each Al have their own fixes or adjustments to minimum each.
THEY ARE TWO SEPERATE THINGS. period


Speed because of stagger on the straights is ONLY scrubbed off because of excessive use of one or the other rear tire. period.
The fix depending on available hp is to either increase or decrease the grip at one or both rear tires.
Which rear tire or both you need to fix depends again on available hp AND your ability to change how both or one rear tire is gripping.
It's all about reducing any conflict or fight for acceleration between your two rear tires at all places around the track where acceleration is possible.
Beyond that it's about reducing any conflict for control of direction between your front and rear tires.

Perfection/balance is all four tires rolling and turning while accelerating, decelerating and maintaining speed in the direction you want to go.

The only thing which makes a LTO karts faster in turns then sprint karts is their ability to reduce the need for front tires to do "ALL" turning.
The only thing which makes sprint karts faster when going straight then LTO karts is they do not need to slip a tire when going "STRAIGHT".

ANY time either a sprint kart or a LTO kart is NOT going straight, except for when stagger on a LTO matches exactly to the radius of a turn, one of the rear tires or both MUST slip.

... well right or wrong, that was fun to writ

Al asked: "Caster is used in Sprint racing to get the inside rear tire off the ground. It needs to do that in order to turn. With stagger, why would you need to do that"

It's not a matter of weight leaving the inside rear Al, it's about the ">>>FACT<<<" in a turn it ">>>always will<<<" leave the inside rear.

I think it is you Al who often proposes a rolling tire offers the least resistance.

Since even with stagger because turns are not perfectly round, except for where stagger exactly matches up to the radius of the track one tire or both tires have to slip and offer rolling resistance.

Perfection then becomes about how you match the amount of unloading of the inside rear per stagger, tire grip, track grip and how your racing is using track banking according to weather your slowing down maintaining speed or accelerating, to use your inside rear tire to accomplish something needed. In a nutshell if your using the resistance between the inside rear tire and the track to provide something you need then it can not at anytime be scrubbing off speed.

An example is when you're on a straight with more then enough available hp to slip either or both rear tires, you may be gaining your acceleration strictly from the INSIDE REAR smaller tire and slipping your OUTSIDE REAR tire.

Why would you even want to do that, you might ask Al?

The reason would be to accelerate using your sudo low gear off the smaller INSIDE REAR tire and at the same time also be putting preload on your INSIDE REAR tire for entry to the next turn.

Any time you use stagger outside of a perfect circle it's use will as you correctly often say on here: ">>>ALWAYS<<<" offer resistance.
Yes you are absolutely correct Al about stagger offering resistance on the straights.

Butt Al it will only scrub off speed depending on a lack of available hp or not being in a position on the track where it is necessary to reduce built up momentum.

There's a difference Al between scrubbing off speed and reducing acceleration.
Yes I expect understanding the difference to be difficult.

Each Al have their own fixes or adjustments to minimum each.
THEY ARE TWO SEPERATE THINGS. period


Speed because of stagger on the straights is ONLY scrubbed off because of excessive use of one or the other rear tire. period.
The fix depending on available hp is to either increase or decrease the grip at one or both rear tires.
Which rear tire or both you need to fix depends again on available hp AND your ability to change how both or one rear tire is gripping.
It's all about reducing any conflict or fight for acceleration between your two rear tires at all places around the track where acceleration is possible.
Beyond that it's about reducing any conflict for control of direction between your front and rear tires.

Perfection/balance is all four tires rolling and turning while accelerating, decelerating and maintaining speed in the direction you want to go.

The only thing which makes a LTO karts faster in turns then sprint karts is their ability to reduce the need for front tires to do "ALL" turning.
The only thing which makes sprint karts faster when going straight then LTO karts is they do not need to slip a tire when going "STRAIGHT".

ANY time either a sprint kart or a LTO kart is NOT going straight, except for when stagger on a LTO matches exactly to the radius of a turn, one of the rear tires or both MUST slip.

... well right or wrong, that was fun to write
Read this 5 times now & it's starting to sink in a little. (I am very hard headed according to my wife). Got into kart racing 1 year ago with my kids thinking this will be fun. Has been more fun for me learning this setup stuff I'm sure. If I were just the crew chief & not the main sponsor I would have been fired already. Looking at my scales with Kart wheels straight I thought it seemed odd that the LR would weigh a lot more than RR would. I would have never thought of the big fat RR could be the one slipping going down straight away. Now I need to experiment with with putting less prep on the RR & maybe few pounds more to left side weight. I wish I was a faster learner for kids sake.
 
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