Front stagger vs caster

H

hotelcalifornia

Member
Why couldnt we just add some left front caster if the left front is too small?

Ive really been wondering why more people havent tried reverse caster, and lower caster like msquared said, considering he was talking about how he whooped peoples butts with it
 
Most don't want to get away from what works. There are some out there that can make a lot of things work, but there is other parts that go with it.

Simply reversing caster isn't going to make it fast, you have to understand what reversing Caster does, and how to adjust the chassis to utilize that. Most setups wouldn't work with reverse caster. Most wouldn't know where to start, and I don't mean that in a condescending way or anything like that. But, wrapping your head around the way most karts are setup and why that's fast is hard enough for most, and I'm one of them.

My understanding of how it's suppose to work is a bit fuzzy, but I think it needs low cross for reverse caster to work. Again, that could be wrong. But, I think you'll be looking at very neutral setups. IE: low 50's cross type setups.
 
I would think a significant adjustment to VCG would come into play as well.
I'll leave the smart guys explain that,
Shaw 95 where ya at ?
 
95 shaw is shoveling snow to facilitate traction to maybe get to work.

Al and I talked at length about caster actually becoming camber as the wheels are turned.
Scrub radius as it actually works has a major influence.
At turn in, the rf jacks very little weight, but during counter steer, jacks a lot of weight.
Because of static positive camber, the lf jacks a lot of weight at turn in. Counter steering unloads this load path.

Search scrub radius, kingpin inclination, and caster.
 
hotelcalifornia said:
Why couldnt we just add some left front caster if the left front is too small?

Ive really been wondering why more people havent tried reverse caster, and lower caster like msquared said, considering he was talking about how he whooped peoples butts with it
Click to expand...
If your left front tire is too small why would you add caster to the left front which will raise the left front tire up and I would think that would make it act as if you put a smaller tire on, not a bigger tire. and ?????????????????????//
 
paulkish said:
If your left front tire is too small why would you add caster to the left front which will raise the left front tire up and I would think that would make it act as if you put a smaller tire on, not a bigger tire. and ?????????????????????//
Click to expand...
raising caster makes the tire go down more when you turn left
 
For the op.
Chassis for lto, are designed largely around tires of a specific rollout, on wheels of a specific width for each corner.

Realistically, anything can be made to work. Even if you don't understand why it works.

Changing caster to compensate for small amount of rollout differences may have unintended consequences.
 
Since the front wheels aren't coupled like the rears, front stagger simply pre-loads the front corners (adds twist or removes twist) differently. The stagger affects the spindle centerline height, which (when coupled with washer stack) determines the initial preload. From there KPI and caster determine how quickly that load changes and where it goes when you turn the wheel one way or the other. If you changed the stagger by 1/4" of diameter and then moved the washers around to put the contact patch back where it started, there would be no net difference on the chassis other than the loss of adjustablility in whichever direction you moved the washers... Changing the stagger on the front theoretically changes their spring rate touch, but doesn't really affect their inherent assistance to turning like stagger in the rear does. Stagger in the rear induces a counter-clockwise moment to assist rotation when equal weight is on the rear tires. It can also be used alternatively to "drive off the right" at a different rate than "driving off the left" if the weight balance is shifted enough. On the front, you're affecting the spring rate of the chassis and not inducing a moment.
 
I 1,000% disagree with reverse caster not working! It does work! In my setups the only thing I changed was front stagger. That is it. Put 2.5" of front stagger in. If it pushes coming off, reduce the stagger until it stops. Front stagger in a kart acts as a reduction in overall caster. So, you must compensate for that. My front caster was LF 10 RF 6 with a front stagger of 1.75"

All of this depends on a number of things.
Ackerman
Steered camber gain at 5 degrees of steering.

You have to look at the weight gain/loss of each of the tires with steered input.

Ted is getting it. But it goes a lot deeper.

Mike McCarty
The Original Chassis Manual
 
^^ Soft pressures also dampen the effect (and rate) and mush the contact patch. I suspect some use this to use part of the sidewall as additional tread. I wonder if we're running tires too wide and too soft to get heat into them to work them "properly." I've been tempted to try a narrower tire, higher pressure, and less prep. I'd be curious to hear more about your setup....Private message fine if you prefer and are willing to oblige...
 
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