Long Travel BS Thread

Say you have a 18x600 currently.

At ride height the spring measures 14”

18-14=4”
4x600= 2400lbs of spring force.

Once you know the spring pressure to support you just divide your spring pressure by whatever spring you are looking at. The number you get is the preload required for that rate to support your truck. This works for going up or down in rate.

 

FWIW, depending on your timeline. Summit racing stocks eibach springs and I can usually have them in 2 days with regular ground shipping. Obviously going to depend how close you are to a warehouse etc.

 

Unfortunately quick check showed them out of stock and drop shipping but usually yea they are actually overnight

and

1400 corner weight at tire to ground interface.
Yea I had no idea how close to coil bind this setup was before today

 

Wouldn’t be shocked to see you in the realm of a 16x650 or 700. There comes a point with 18’s where the coils are simply too thick to work even with no preload.

 

Wouldn’t this technically be the amount of preload your spring has?
18” free length - 15.625” ride height measurement = 2.375” preload

 

That’s correct. An 18” spring is compressed roughly 2” installed on an 8” coilover with no adjustment.

 

My take on preload is: The amount the spring is compressed when installed on shock prior to the vehicles weight is added and not compressed from any other factor. Basically, how much that spring is compressed installed on the shock and the shock on the bench. Hence the term Pre-Load. Which in turn means when the shock is at full extension the spring is still loaded/compressed. So if you have a 500lb per inch rate spring and there is an inch of Pre-Load when the shock is at full extension there is still 500lb of stored energy in the spring.

 

no, preload is free length - coil collar compression, so if your ride height spring length is 15.625, and at max droop you have the collar set so the spring is at 17" you have 1" preload.

 

aaand after going back a few posts,

yeah this was preload amount... based on how Blueberry was setting up the rig.

and @Blueberry.Taco you would be hitting coil bind before full comp based on your measurements.

I'm planning to switch to a 20" 400lb spring, set at 18" drooped length on an 8 inch stroke with a 9in block height... with 1600lbs front corner weight...

@906taco @Blueberry.Taco @Caboose117 we should have a east coast meetup in the UP sometime next year! when my truck is ready and my wife lets me...

 

Wait I swear I did the math and am fractions of an inch from coil bind. What did I screw up?

after 50 miles of local roads I’m back to the ride height of this morning before I increased the preload.
at current ride height:
39.0” at the bottom of the stock fender flare to ground
21.0” e2e (4.75” rod showing)
notes for myself, this fox is a 23.5” max ext, 6.75” travel shock
At full extension was 15.25” coil height (2.75” compressed for 18”)
Ride height is 2” shorter so 13.25” coil height (correct preload terminology should be here, 18-13.25”=4.75”, but you can see why everyone has different definitions and it just causes confusion)
Full compression is 6.75” shorter so 8.5” of coil height…. Which is taller than stack height of 8.43”, so safe?

Also where is everyone at in the shock travel for ride height? Wondering if my fairly arbitrary ride height target based on where the rear sits is misguided…. I am willing to sacrifice crawling performance to be “softer/more reliable” which biases me to have more up travel than down travel. So at the shock I guess I’m currently 2” down, 4.75” up. Which seems kind of high now that I look at the numbers.

yea for sure although I’m not gonna keep up with any of you guys on the trails, just have the glampiest setup at camp.

 

That's a lot of numbers

 

I have no idea what this all means I'm trying to track it but I'm pretty ignorant on actually calculating the correct spring rate. My foxes came with 16" 600 lb springs and they are softer then shit. I think I need to step up.

 

I get notifications for this thread so I open it at work. I read it when my brain is fried from a long day and just stare at this shit like wtf

 

Willing to drive regardless
Just wanna eat new food

 

Preload is any compression of the spring installed on the coil over. An 18” spring automatically has preload installed on an 8” shock. A 16, doesn’t.

If you don’t count that 2” of installed preload, you’re going to get yourself in a major pickle with coil bind.

Count ALL compression as preload.

An 18x600 has about 1200 pounds of preload installed with the coil adjuster at 0 adjustment.

 

I’m sitting right on the 50/50 mark for travel with 18x500. I’m also right on the line of coil bind at full compression. Want to say my frame height at body mount location is about 18”. Can confirm when I get to the shop.

 

@Blueberry.Taco heres how mine is sitting. Bypass shows 4.5” of shaft at this height.

 

Just an update for those following along..
With hurricane and heatwave I have not departed to cali yet
School still starts in august like always
So, I’ll be out there soon, just haven’t left yet

 

Surprised you went with that style of cab mount. I have the same and I'm scared it's going to punch through the frame

 

It serves zero purpose really. It just gave me room to run my pontoons for the cage. Really the only reason it’s there.