macr88

My bathroom scale that measures ounces hahaha funny
BTW that was in reference to weight distribution using rake and you said you can distribute more weight to the front or rear by raising and lowering one end of the vehicle by a 1/4" and my point was the angle would have to be extreme. But anyway different topic and long past.


It's true you do have scales but that means nothing to me.

mikegarrison

This is true. You can move weight back and forth using rake angle, but the effect is so very small that it is insignificant.

DCIdevil

i didn't know that this could even be a debatable topic..
heated none the less.

You may be able to adjust CW with preload but the shop i take it to does it with height at each corner.

Orthonormal

It really doesn't matter which adjustment you use - body length or threaded seat - the distance you're moving either adjustment for corner balancing should be so tiny that it's not going to eat into your shock travel.

If it does, it's time to put your car on the frame rack.

Orthonormal

PS I think it's hilarious that some of you keep referring to the threaded seat position as "preload". Read too many JDM shock brochures?

macr88

If you consider Ohlins JDM then yes.
John, what would you call it? The spring perch adjuster?
It's preload whether the spring is negatively preloaded (when helper springs are used) or positively preloaded like with soft springs.
People think preload is some magical thing but it's used to adjust the position of the valveing in the body, something that is crucial on short bodied dampers but not as much of an issue on longer dampers.


I don't understand why it can't be a discussion.
I understand the whole table idea but the table idea is missing a crucial element (springs). To me the table idea would be better suited to explain the effects of different length dampers vs dampers that have different weight on them. Preload still changes the static length but not the mechanical length, even if it is 1mm to me it still seems like a negative effect to adjust the overall mechanical length even if it's only 1mm and realisticly won't make a difference.

I will continue to CB my car using the same adjuster that Mike uses because that one is the one that makes sense to me. Whatever you want to call it, I'll call it the lower adjustable spring perch

bellwilliam

if your coilover has separate adjustments, one for preload, one for shock body length.

it has different effect if you do one over the other. see my earlier long post. but here is a part about it:

"If you are at a certain setting and you decide you want to go lower, do you adjust the pre-load or adjust the shock length. Well, if you shorten the shock you maintain the bump travel, but your tire might rub or A-arm might hit something on large bumps. If not, then it's OK to do that. If you adjust the spring perch ("pre-load"), then you will reduce bump travel but maintain the wheel position at bumpstop touch and full bumpstop compression. If your springs aren't stiff enough, then you might be cornering on the bumpstops, which is not recommended unless the whole spring/shock/bumpstop system has been designed that way"

macr88

Completely understood, but that is in regards to lowering the car or if you have clearence issues on bumps meaning a solid suspension component or tire is at it's end before the bump stop stops it.

Let me try a different approach. Lets say your spring is not exactly the same which they never are. You have 3 springs at 500lbs and one at 475lbs and you have a 2000lb car that was equally ballanced (500lbs in each corner). The 475lb spring is going to compress a bit more which will remove load on the opposite end and carry more load on the other two corners. Left rear/right front and right rear/left front.
So for all the springs to carry the same weight preload must be adjusted due to the softer spring, because that spring at 500lbs would have to compress a little over an inch where the others would be at 1 inch. I don't see difference between having the 500lb spring with more weight on it or the 475lb spring. You're just adjusting the springs resting point higher or lower.

I think adjusting mechanical ride height to corner balance came from the same people that think adjusting preload increases or decreases spring rate, it can only change the effectivess of the spring if your bottoming out. Ride height which is an effect of preload can change the ? Not sure what it's called but it's kind of like leverage which will effect how the car feels and may in fact make it feel stiffer or softer.

Mike, I hope you don't mind the discussion, I just want to learn more and now I think I understand.

macr88

I agree but think that one is better suited than the other. Kind of like adjusting the idle, you can do it with the butterfly but why not just adjust it with the idle screw.



I understand but
You could have a bad spring which is more likely. Don't want someone thinking they might have a bent frame when it's their spring.

Orthonormal

It's just funny that you're so adamant that it should be called preload, when it adjusts two things at once.

Many high-end shocks do not have adjustable body length, and the spring seat height is used to adjust ride height and cross balance.

If you think about it, having that threaded cup takes a chunk of length off the internal volume of the body, reducing the total range of motion. The cup may allow you to change the ride height while keeping the neutral position in the middle of the shock travel -- but you have less total travel available. By moving the seat height you are moving the neutral position closer to one extreme of travel, but in the end you may not be any closer to that extreme than with an adjustable-body shock because there is more travel available.

I'm not saying you should use one adjuster or the other, just that neither adjuster is the wrong way to do it.