Need help with caster.

Gravey39

Member
I have older style spindles. I’m trying to figure out how to adjust caster as in reducing from 10 degree to 8-5. I was wondering if mourning to the top of the spindles would work. And how would I do so. I have two pictures to reference it. The blue ones are mine, and the red is a picture of it done that way.
DBF617B9-2057-411E-87AA-42D1FCA234CF.jpeg
22E47C0E-65A2-4D57-8E9A-3467A758EFEE.jpeg
 

Ted Hamilton

Design Drafter / Racer
The castor is built into both of those chassis and can only be changed by physically bending the tubing (or twisting) by means of a LONG strong rod and some torch work. Not advised. Are you running asphalt sprint karts like these, or oval karts?
 

01ron

Member
Not true. The red kart has an upper pill with caster added from built in caster. If you turn the pill on the red kart 180 degrees, you will decrease caster from the built in caster. You can not see the top of the kingpin on the blue kart so its unknown if there are pills installed or not. Also, the red kart pill is slightly turned probably to adjust camber to the desired reading.
If you have pills on the top of your kingpin, anytime you align them so the thicker part of the pill is forward, you are adding caster. Move them where the thicker part of the pill is to the rear and you are removing/reducing caster.
 
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XXX#40

2A supporter
Not true. The red kart has an upper pill with caster added from built in caster. If you turn the pill on the red kart 180 degrees, you will decrease caster from the built in caster. You can not see the top of the kingpin on the blue kart so its unknown if there are pills installed or not. Also, the red kart pill is slightly turned probably to adjust camber to the desired reading.
If you have pills on the top of your kingpin, anytime you align them so the thicker part of the pill is forward, you are adding caster. Move them where the thicker part of the pill is to the rear and you are removing/reducing caster.
Those are for adjusting camber more so than caster
 

Ted Hamilton

Design Drafter / Racer
True, I missed the old style adjuster. It's probably only good for a couple of degrees. It does adjust camber and caster at the same time in any position other than 90* or 180*.....that's why the sniper type and other independent systems were invented. It's probably am 8mm kingpin... My bad on that. Still, it's limiting. Turn the adjuster nut so that the wide part is toward the wheel, and that will be the max negative camber. Opposite will be max and possibly positive camber...Front to rear settings will take out or add castor relative to the fixed castor built in.
 
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01ron

Member
The original poster is looking for caster solutions. See my posts above. And I think your recommendations are backwards. If the wide part is towards the wheel, its in the max negative camber setting. Put the widest part towards the center of the kart and you will get max positive camber. This applies if you are tuning with a pill on the top of the kingpin. Everything is reversed if you are adjusting with a pill on the bottom of the kingpin. Some of the newest "winning" sprint karts being built now are still using the "old style adjuster" including the Comet Eagle and MGM. Also Margay still uses pill systems on their karts. Some of the best karts in the sprint racing world are still using pills.

Also, all the euro karts that I know of use pill systems also except for the few that use the sniper system..
 
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Gravey39

Member
Not true. The red kart has an upper pill with caster added from built in caster. If you turn the pill on the red kart 180 degrees, you will decrease caster from the built in caster. You can not see the top of the kingpin on the blue kart so its unknown if there are pills installed or not. Also, the red kart pill is slightly turned probably to adjust camber to the desired reading.
If you have pills on the top of your kingpin, anytime you align them so the thicker part of the pill is forward, you are adding caster. Move them where the thicker part of the pill is to the rear and you are removing/reducing caster.

I own the blue kart. It doesn’t have pills(yet) just kingpin bolt. I was just wondering if and how do I instal the pills to the spindles. And if it would actually take some of the caster out. I run lo206 class in sprint asphalt and a guy who knows a lot about emmick chassis said I should find a way to take some caster out because they run stock 10 degrees of it which has too much side bite for that motor. Just trying to figure out the best possible way to use the pill on the actual spindle and not the chassis. Since the bearings are in the said itself.
 

Gravey39

Member
The original poster is looking for caster solutions. See my posts above. And I think your recommendations are backwards. If the wide part is towards the wheel, its in the max negative camber setting. Put the widest part towards the center of the kart and you will get max positive camber. This applies if you are tuning with a pill on the top of the kingpin. Everything is reversed if you are adjusting with a pill on the bottom of the kingpin. Some of the newest "winning" sprint karts being built now are still using the "old style adjuster" including the Comet Eagle and MGM. Also Margay still uses pill systems on their karts. Some of the best karts in the sprint racing world are still using pills.

Also, all the euro karts that I know of use pill systems also except for the few that use the sniper system..
D9BAC4B7-494E-40CD-B799-92011AAF7D09.jpeg


this is what the top looks like. It’s just a hole for the kingpin with a standard washer. I was going to try to get pills and machine the head a bit so accept the pill. Just didn’t know if making the adjustments from the spindle itself would be the same results as moving the kingpin.
 
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Gravey39

Member
The castor is built into both of those chassis and can only be changed by physically bending the tubing (or twisting) by means of a LONG strong rod and some torch work. Not advised. Are you running asphalt sprint karts like these, or oval karts?
The blue kart is mine, which now has cosmetic upgrades. But which. I just trying to come up with a way to take some caster out to about 8 to 5 degrees instead of 10. Was going to add pills to the top of my spindles just like the red kart. Just wondering if that would work. I keep hearing multiple opinions from different people. So I cannot find an actual way to do it. I have an emmick chassis and they used to use invader pills. Mine never had them.
 

01ron

Member
10 degrees of caster is not very much at all on a sprint asphalt kart. But if you insist on changing the caster, machining the top kingpin hole on the spindle would be the correct way to go. Once again, the way the pill is installed and adjusted on the red kart is ADDING caster, not REDUCING caster.
 

Ted Hamilton

Design Drafter / Racer
Also curious...what is your motivation for changing what's there, settings-wise? Is the kart not doing something you'd like it to? Somewhere around early 2000's kart tuning theory changed, as did geometry. Now a wide scrub radius is used, and caster/camber not played with as much, from what I can see at events... The whole front is also wider on modern karts. Pre-2000s, track width was varied to achieve balance, now I see a lot more tuning at the rear and leaving the front in a narrower window... This may also have to do with the built-in ackerman columns too... Just wondering what you're trying to do by reducing caster?
 

Gravey39

Member
Also curious...what is your motivation for changing what's there, settings-wise? Is the kart not doing something you'd like it to? Somewhere around early 2000's kart tuning theory changed, as did geometry. Now a wide scrub radius is used, and caster/camber not played with as much, from what I can see at events... The whole front is also wider on modern karts. Pre-2000s, track width was varied to achieve balance, now I see a lot more tuning at the rear and leaving the front in a narrower window... This may also have to do with the built-in ackerman columns too... Just wondering what you're trying to do by reducing caster?
Well I was just curious about my frame one night and got in touch with a guy who knows a lot about the emmick cobras(rod van dueson). It was my fathers kart and it’s from 98. It’s still a very competitive kart with the lo206 on it. But he told me to try to take caster out of it a little bit and it’ll drive a lot better. I really don’t have any issues with the kart at all. I can still run in the top and put down the fastest lap times on this kart at the local track. If there was a way to make it better then I wanted to try to do it. He explained that this chassis was built for all engines, shifter, 2 cycle and 4 cycle. But when they used it in a 4 cycle application they took caster out to 8-5 depending on driver. That’s really my only motive. Just couldn’t ever find the correct information on how to apply caster and camber pills to these type of spindles.
 

sundog

Member
If the hole though your bracket is the same size as your king pin then you have a problem adding castor pills. The pill is a shoulder bushing that has an off set OD so when you turn the pill it moves the king pin. You can have one on top and bottom for max adjustments. The hole in the bracket has to be bigger than the king pin for this to work. Frankly it's a can of worms because the camber will also change and you have to be good at taking up the slack as you tighten it down or it will change first bump you hit also you have to have a flat level surface and be very good at measuring these things.

If it was made for shifter engines then it's a strong frame and a little castor goes a long way so you friend gave you good advise in general. It also has to do with your vertical CG, are you tall or short? If you're on a track with allot of lateral G force Like a short tight track then you can reduce castor. On a longer open track you need castor to jack the inside rear tire and to steady the kart on straights.

For LO206 I would set the toe straight ahead, make sure your camber is straight up or slightly negitive, forget about castor and focus on your front and rear track widths and tire pressure. Looking at those pictures I would get new nuts, bolts and cotter pins on that steering system before the end of business today.

Sundog
 
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alvin l nunley

Premium User
Castor pills came out after I quit building, so have no experience, do you have a drawing so I can figure out how much castor/camber they add. After I stopped driving and building, I remember seeing castor pills in other karts, and I always wondered how much change in castor/camber they could achieve. You realize of course, if the offset is at 90° to the frame rails, you can change the camber, if they're in line with the frame rails, you can change the castor, rotate anywhere in between, and your changing both. I've never thought that was a solution to any problem. I'm pretty sure they are a feature that helps selling karts.
 

alvin l nunley

Premium User
If the hole though your bracket is the same size as your king pin then you have a problem adding castor pills.

Sundog
Just a friendly suggestion; it's the spindle that moves, not the bolt.
 

01ron

Member
I have measured the caster changes with a 1.5mm offset pill and a 3mm offset pill on a Comet Eagle (zero pill on bottom). The 1.5 mm offset pill adjusts the caster + or - 1 degree from neutral caster. The 3mm offset pill adjusts the caster + or - 2 degrees from neutral caster.

I also want to apologize for correcting Ted Hamilton. I have been used to tuning karts with the "C" on the chassis, not on the spindle. All my info above concerning caster refers to the "C" on the chassis. Now that I revisit the "C" on the spindle, I believe everything adjusts 180 degrees out from what I am familiar with. The red kart with the pill larger offset to the front would be moving the spindle forward, thereby reducing caster from the neutral position. Al and Bob Evans' comments got me thinking and I stand corrected. Sorry.

With the "C" on the kart, the kingpin moves with pills. With the "C" on the spindle, the spindle moves with pills and the kingpin does not.
 
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Jc53

Member
With the "C" on the kart, the kingpin moves with pills. With the "C" on the spindle, the spindle moves with pills and the kingpin does not.

Ron, I agree. Castor is the inclination of the king pin axis relative to the ground plane in the side view. To change castor you need to move the angle of the king pin bolt relative to the ground. Pills on the spindle shown on the red kart are only rotating the spindle and changing camber.
 

01ron

Member
Maybe I did not make myself 100% clear. Changing the pill on the spindle does not affect the kingpin caster but effectively moves the spindle forward or backward. This would create the same affect as changing the actual kingpin caster angle. I could be wrong so correct me if I am. It's a really abstract issue.
 
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