Shock Tech Ep. 3: Preload

What you need to know about spring preload and why it is important.
If you have any questions or need help with your setup feel free to give us a call or shoot us a message.
www.accutuneoffroad.com

[@bobmalarkey4621]

Next time I do a suspension on a truck, I'm definitely going with you guys instead of ordering a bunch of stuff that I thought would work.
Ordered some springs from y'all today. Not even 10 minutes later, I got a phone call from one of you double checking my order, and got me the set of springs that I actually needed because you guys know your stuff. That's service. The reason why I had to order new springs is because Fox sent me the wrong coilovers TWICE! and one set already blew the adjustment collars because their tech support told me some bs about how much preload I needed on their own product. They decided to send me another set, but sent me the exact same thing that I had and not what they said they were gonna replace my orginal set with. So now I have 4500$ worth of coilovers sitting on my garage floor until they decide whether they're gonna give me my money back or not. I've got a feeling that I'm screwed on this one.

[@shootinbruin3614]

What about during a jump where the suspension is fully extended?
If we land from a jump, am I correct in assuming that the preload must be overcome before the suspension begins to compress? If so, does this mean that until upward travel begins, the impact of the tire with the road isn't mitigated by the spring, making for a harsh landing?
If this is correct, does this mean that the ideal spring setup for a vehicle meant to jump is one with zero preload? I.e., adjust for desired ride height by experimenting with different spring rates while leaving preload set at zero. This way, very little force is transmitted directly to the chassis before the suspension begins to move.
Normally, this kind of spring rate would be far too light to cushion the blow of the landing but from what I've learned a good shock will take care of that. Of course, I could be completely wrong which is why I'm asking. Thanks!

[@andreluizpereira366]

I ´ll use a 2.0" sway-away 16" in in a lightweight rockcrawler rig here in Brazil what do you recommend?

[@prajwalg9320]

Hey Ryan,
Can I know on what formulae and equations will you design digressive, linear and progressive piston?
If you have any excel sheet or formulae sheet can you please share.

[@zombieqtr]

I currently have a 16 inch KING coilover on my LC200 with a 700lb spring. It currently is sitting at the correct ride height 2.5 inches of lift with zero preload. Would you suggest I drop to a 600lb spring and add preload?

[@accutuneoffroad]

Hi, it's best for you to call the shop and we can figure out the best solution for getting you some preload. Thanks!

[@martywolf1819]

Good video I'm not that sharp but I kinda get it I will have to watch it again when I'm by my car and start checking my preload

[@zombieqtr]

Awesome video Ryan never thought that preload was so important.
If I add more preload will that have the same effect of lighter rebound damping? , Will it make the tire pop out faster after compressing.
My vehicle is now already topping out harshly when catching air and dropping from square edge bumps, it is at zero preload. If I add 2 inches of preload will it make it pop out even faster?
Maybe I should throw in a heavier rebound stack and add preload.

[@accutuneoffroad]

Yes, preload is an important part of a properly functioning suspension. OEM vehicles with short travel sometimes need to break the rules, but based on your comments I would go to a softer spring and add rebound.

[@zombieqtr]

@@accutuneoffroad Awesome thank you for your time.
Just to be 100% sure. Is the goal always to have 2 inches of preload upfront ?.
I also saw on your preload article that with 3 inches of preload the result spring rate was softer than zero preload, I am guessing it makes the spring softer.

[@accutuneoffroad]

@@zombieqtr The front of most lifted IFS trucks are unique and require different approaches depending on their setup. We do not have a "standard preload" recommendation.

[@andreluizpereira366]

Do you charge the schok with 150lbs of N2 before setting the pre load?

[@accutuneoffroad]

Fully extended Fox shocks should be charged to 200psi of Nitrogen and King 150psi. Preload can be adjusted after

[@gelo_tiongson]

Hello, i have a KYB JAOS BATTLEZ Suspension on my hilux 4x2, what i am very curious about is the preload settings, the one that fitted it on my rig is not sure on the proper preload for the coilover. now i am the one who is adjusting it and what i am after is for the comfort ride on the front. do i have to set it to zero preload then adjust to 5mm of thread to have preload so that the spring is not that compressed to absorb small bumps? the ride now is okay but still have room for improvement. i still feel small bumps even the damping is set to the softest settings which is 1 out of 14 clicks. thank you

[@gelo_tiongson]

btw i checked the droop and it measures about 65 which is good for the hilux. minimum required good droop is 60

[@jwdiho]

How are you maintaining the same amount of droop when you add 3" of preload to the system?

[@robconlin4815]

You are not with the same spring. You want the correct spring with the correct preload.

[@karthikkailash535]

3:25 - could you explain how you arrive at the numbers shown?

[@accutuneoffroad]

(preload+shaft_droop)*spring_rate*motion_ratio Motion ratio expressed as a fraction, eg: 0.5