Is there a 2" or 3" rear progressive or dual rate spring that actually works?

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Just adding my 2 cents. I've got the TJM 50mm dual rates and I've like them (for the most part). I have no additional armor except sliders, and very little additional weight of any kind. Stock they sit great, just a little tail high.

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But add a load and they squat.

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I'd say about a 2 inch swing from unladen to one guy and his stuff levels of load. If Im pulling the trailer I lose all 2 inches of lift

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I've been asking myself the same questions you have (minus stinkbug cause I don't really care about it). I've come to the conclusion that if you want a spring that rides well and has a fixed ride height regardless of load you are looking at air. plain and simple. What you are asking for in a steel spring isn't really possible.

Here is my thoughts on dual rate springs like the TJM

Pros -
They have a nice unladen ride but I've found that shocks play a huge role here, my ICON VS2.0 have stiffened up my ride considerably over the TJM adjustable dampers.
They flex like crazy and stay in their perches. With the Longer ICON shocks I can flex the rear WAY more than fixed rate coils.
A decent tradeoff between load and ride
Great bottom out characteristics.

Cons-
Dual rate means your shocks work harder, as the bound and rebound rates aren't linear in their travel (or load dependant). Meaning as the spring loads up the 2nd coils there is a heavier rate that the shocks need to be able to damp, but as they unload and the top coils come out of coil bind the rate changes and you find yourself in the wrong damping curve for one of the 2 rates. i.e. you have a soft rate with a great ride that moves around too much laden, or you have a harsh rate unladen with control while laden.
They clank, some spring isolators might help.
They wont respond like a linear spring to load, they will act soft
They are in coil bind (or near) in the soft rate most of the time which makes for a shorter effective spring (acting like a stock height spring with a spacer vs a full height spring).

My plan I think is to find the lightest constant rate coils I can find with a tall free height and put bags in them to control the load. Like a Slinky coil.

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Im running the ICON 75mm kit and I love it. They are dual rate springs.

Here it is at GSMTR loaded down with gear: hilift jack, full ARB recovery kit, tools, cooler, with a 17x7.5" steel spare with 315 mounted on steel bumper mounted tire carrier.....no third row:

IMG_6095.PNG



And here it is with nothing in the back, no spare, no third row, and before I added the ARB side bars......

IMG_5690.JPG



I realize the loaded pic isn't a good profile, but I have noticed how little the height changes with relatively large changes in weight.

I love this suspension. I took this LC to Windrock for GSMTR last month and went everywhere. Ran all of Trail 21 and another DOUBLE black diamond. (Not the GSMTR group rides) It performed great, very nice flex. Not as much droop as the Slinky Im sure, but really good. Im no expert on this, but dollar for dollar, its got to be one of the best systems out there. ($1600 shipped with everything, including awesome shocks, CC bushings, rear swaybar relocation kit, extended stainless brake line.) Rides great on the highway. Like a Fleetwood Brougham, only it handles better. :D

:beer:

EDIT: just realized how old this thread is! oops
 
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My experience with TJM is similar to @hammerheadfistpunch I get a ton of squat when I pull the camper, but for normal driving and wheeling, I'm not carrying that much weight. I'd rather have it set up to ride where I want 90% of the time and just let it squat when I tow. They actually handle and ride great loaded down, they just look goofy. I do think I need more shock though, the handling is a bit sloppy and I still have only replaced about a third of my suspension bushings (all of which are worn).
 
that's why i like the tapered Dobinsons. They ride great unloaded and don't squat much at all when loaded up for a trip. Best of both worlds...for the extra money.
 
cavboy78 said:
that's why i like the tapered Dobinsons. They ride great unloaded and don't squat much at all when loaded up for a trip. Best of both worlds...for the extra money.
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Which are you running 2.5” or 3.5”? If 3.5”, can you post pics?
 
cavboy78 said:
that's why i like the tapered Dobinsons. They ride great unloaded and don't squat much at all when loaded up for a trip. Best of both worlds...for the extra money.
Click to expand...
That's what I like about the Slinky coils too. Awesome ride unloaded, but with a full load of gear and my family of 6 inside, along with all the armor and tent and pulling my trailer there is hardly any squat. Best quality dual rate coils on the market. Also nice that there are intermediate, heavy and extra heavy spring rates available depending on what you need. I'm running the heavy springs and they've been awesome.
 
Box Rocket said:
That's what I like about the Slinky coils too. Awesome ride unloaded, but with a full load of gear and my family of 6 inside, along with all the armor and tent and pulling my trailer there is hardly any squat. Best quality dual rate coils on the market. Also nice that there are intermediate, heavy and extra heavy spring rates available depending on what you need. I'm running the heavy springs and they've been awesome.
Click to expand...

I would have gone with these, my first choice, but this is back when stock is scarce...
 
2.5" with spacer
2013616
 
2013618
 
The pics are loaded up for a one week trip with very little sag, as you can see. I think i posted elsewhere on here, but similar load out on the OME stock height springs (with spacers/dual rate) and I was bulldoggin' pretty badly.
 
cavboy78 said:
that's why i like the tapered Dobinsons. They ride great unloaded and don't squat much at all when loaded up for a trip. Best of both worlds...for the extra money.
Click to expand...

Also curious which height you're on. Really considering the 2.5" tapered.

Box Rocket said:
That's what I like about the Slinky coils too. Awesome ride unloaded, but with a full load of gear and my family of 6 inside, along with all the armor and tent and pulling my trailer there is hardly any squat. Best quality dual rate coils on the market. Also nice that there are intermediate, heavy and extra heavy spring rates available depending on what you need. I'm running the heavy springs and they've been awesome.
Click to expand...

Does slinky actually publish their rates for the different "ratings"? (disclosure, can't recall in the compiled thread if its there, going to look again now) edit: this is still in there unanswered re Heavy 50mm option:
It seems to be more like a Intermediate coil rather than a HD coil though. To suite lightly loaded 80s, does Slinky offer a true 50mm rear intermediate coil?
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I'm trying to compare the 2.5" dobs tapered to a similar slinky. If There is a heavier duty 2.5" tapered slinky spring than the rates the 2.5" dobs tapered it'd be$$$ for me. I don't want to go to a 3+" lift but still run somewhat light somedays up to full heavy loaded rig for long trips.
 
cavboy78 said:
The pics are loaded up for a one week trip with very little sag, as you can see. I think i posted elsewhere on here, but similar load out on the OME stock height springs (with spacers/dual rate) and I was bulldoggin' pretty badly.
Click to expand...
1” spacer front and rear??
 
I went with the 2.5"tapered because there wasn't a lot of data out at the time and didn't want too much ride height. I am currently running the trim spacers (10mm) in the rear and 5/8" in the front. Disclaimer: The photos above were with 10mm front and back spacers, so the front rides a bit higher now. Stock front driveshaft and slee caster plates.

Flare to hub measurements as she sits unloaded:
Spacers: 5/8" spacer on Fronts and 10mm rear.
Driver Front: 22 3/4"
Pass Front: 22 3/4"
Driver Rear: 23 1/4"
Pass Rear: 23 1/4"
 
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After doing some runs at Cruise Moab this year, I need to extend my bumpstops about an inch in the rear as I never dropped them from stock. Fronts never rubbed and she was pretty flexed out on steel bender.
 
Awesome. That's almost the exact ride height/situation i want to be able to run with 315/35s. Going to try it with no spacers to begin.
When you first installed did you run with no spacers?

How is your overall impression of the springs? Anything to compare to? Were you stock before or on OME or something?

You're the only person who i've found that is running the 2.5 tapered over the 3.5 w/315s. I don't want that additional ride height if its not needed.
 
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