Rear Spring options for ride height and additional load. What do you run and how much lift?

[21200]

I have had the bilstein 6112/5160 combo installed with the bilstein 1.75" lift rear springs for about a year and am very happy with the ride quality and lift height it provides. However, in the last couple of month I have added some weight to the cruiser and when we load up the rear end sags significantly and it wallows on the highway. This is what is permanently installed, and I have a family of 6 so when we take trips we add significant cargo between the people and gear:

Hidden winch mount and warn 12k winch up front
Slee sliders
LRA 12g tank in the rear
When we take trips I use a hitch mounted cargo tray and it can hold several hundred pounds. I only use it to carry bulky items or items that would be unsafe in the cabin.

When the LRA tank and main tank is full, and the cruiser is otherwise empty, it sits right at level if not squatting a hair.
When I look at the heavy load spring options from OME, most of them only offer .5" of lift. The Bilstein springs I have now claim to offer 1.75" lift, though I do not have a measurement of exactly how much lift it provided me. Bilstein makes a "heavy load" spring that claims 1.5" lift, but the additional load rating for that spring is 400lbs, and I am afraid I am going to load the spring enough and itll give a very harsh ride.

So, does anyone have any recommendations for which spring to try to prevent the squat, and give better riding characteristics? I am also considering lowering the front end some to help, but still need a stiffer spring to firm up the ride when loaded.

 

[tominboise]

No help on spring rates for your load, but one can add 5 or 10mm spacers to the rear springs if you need more lift. I did that on mine with good success.

 

[empty80]

Advertised “lift” heights are misleading as they are based on weight assumptions that may or may not true with your truck. Understanding the sting rate is more important. If you know the free height of 1.75” lift springs, the compressed height and spring rates, you can calculate your sprung weight. Then you can compare all manufacturers springs in an apples to apples fashion for ride height provided they give the free height and load rating.

OME 2722 wouldn’t be a bad place to start. I say that because I have a Slee rear bumper, sliders, 24 gal aux, drawers, and a partridge in a pear tree, and mathematically, OME 2723 would lower the rear of my truck level with the front in a hub-to-fender measurement.

 

[Itsky]

Weight it front and rear axles loaded and ask a qualified vendor

 

[CharlieS]

Airbags?

 

[kcobourn]

Airbags?

This. I use Airbagman & LOVE them. All I need is a bike pump + a cheap pressure gauge to keep the truck rake level regardless of weight.

 

[21200]

This. I use Airbagman & LOVE them. All I need is a bike pump + a cheap pressure gauge to keep the truck rake level regardless of weight.

Can you expand on your use of them? When you load heavy, you add pressure to level the vehicle. How does that change the driving dynamics? Does it firm the ride significantly when the bags are in use? Can you adjust the pressure levels easily and on the fly if you also have a compressor on board?

 

[kcobourn]

Can you expand on your use of them? When you load heavy, you add pressure to level the vehicle. How does that change the driving dynamics? Does it firm the ride significantly when the bags are in use? Can you adjust the pressure levels easily and on the fly if you also have a compressor on board?

Have used on my 100-series & immediately installed when I got my 200-series.

Stock suspension here & keep at 5 PSi (minimum loading). When loaded (for road trips) I just measure rake before & fill the bags to keep the stock rake.

Rides just fine & subjectively 'feels' a bit smoother vs no airbags.

They offer stock & lifted suspension options. I chose them because they have a full kit + kevlar sleeves that protect the bags / offer big weight handling if down the road I decide to turn it nto an overlanding rig.

RE filing for my need I just do it manually & it takes like 2-3 minutes. I'd reach out to Airbagman they're incredible service-wise & very reputable Aussie company.

 

[Sandroad]

Can you expand on your use of them? When you load heavy, you add pressure to level the vehicle. How does that change the driving dynamics? Does it firm the ride significantly when the bags are in use? Can you adjust the pressure levels easily and on the fly if you also have a compressor on board?

Adjusting on the fly and/or using a compressor would be overkill. You’ll quickly find the pressure that works best for each load and it takes maybe a minute to adjust each bag with a bike pump.

 

[21200]

Adjusting on the fly and/or using a compressor would be overkill. You’ll quickly find the pressure that works best for each load and it takes maybe a minute to adjust each bag with a bike pump.

The idea of using a bike pump to level out the vehicle is comical for some reason but definitely appealing. Will look into the airbag man.

So ideally I would find the correct spring weight for my daily driving needs (full tank and aux tank, passengers but no gear) and then use the bags when loaded with a trailer or other payload.

Anyone out there with the 12.5 LRA and using OME 2722 springs care to take some measurements that I can compare to my Bilstein springs? I am assuming center of hub to fender line is what we need to compare. Ill measure mine tonight and post tomorrow

 

[kcobourn]

The idea of using a bike pump to level out the vehicle is comical for some reason but definitely appealing. Will look into the airbag man.

Thought the same but that's direction I got from my tech who has been working on cruisers for two decades! The bags are relatively small volume wise you will only need a few pumps.

 

[CharlieS]

You can get airbag pump remote controls with remote pressure monitoring (I've seen them on Eric Sarjeant build videos), but it is probably overkill.

 

[TeCKis300]

If one has on-board air (OBA), it can make filling rear airbags trivial by adding a remote compressor port at the rear. I have both compressor port and air-bag fill ports under the tailgate lid. Easy workflow to grab the fill hose and bump some pressure into the airbags. It's also really handy to level the vehicle with this same setup at camp.

Power Steering Relocation Bracket and Dual OBA

Having done a power steering relocation mod recently for a yet to be completed twinz project, thought this would be useful for others on how to create a simple and effective relocation bracket. I know others have needed to relocate the PS for other reasons, including fitting dual batts. Here's...

forum.ih8mud.com

Adding Airbags to AHC

Picture is probably too subtle to show but it's part of the why - adding airbags creates the ability to level the vehicle side to side and front to back for backcountry car camping. In the pic, I have the right side jacked up 2" with about 25 PSI in the right rear bag. Secondly, while AHC has...

forum.ih8mud.com

 

[Sandroad]

If one has on-board air (OBA), it can make filling rear airbags trivial by adding a remote compressor port at the rear. I have both compressor port and air-bag fill ports under the tailgate lid. Easy workflow to grab the fill hose and bump some pressure into the airbags. It's also really handy to level the vehicle with this same setup at camp.

Power Steering Relocation Bracket and Dual OBA

Having done a power steering relocation mod recently for a yet to be completed twinz project, thought this would be useful for others on how to create a simple and effective relocation bracket. I know others have needed to relocate the PS for other reasons, including fitting dual batts. Here's...

forum.ih8mud.com

View attachment 2947586

Adding Airbags to AHC

Picture is probably too subtle to show but it's part of the why - adding airbags creates the ability to level the vehicle side to side and front to back for backcountry car camping. In the pic, I have the right side jacked up 2" with about 25 PSI in the right rear bag. Secondly, while AHC has...

forum.ih8mud.com

View attachment 2947587

I like that location. I'm going to move my fill valves to that spot.

 

[21200]

Well I ordered the airbag man kit and look forward to testing that out. For now I am going to leave the bilstein standard 1.75" lift springs in. I have the 2722 springs on hand to swap out if that seems like a better fit down the road.

with both tanks full, but the truck otherwise empty and unloaded, my center hub to fender measurements are as follows:
Front 21 1/8"
Rear 21 7/8"
Was glad to see these measurements were the same on each side (to within 1/8th inch).

Interested to see where everything sits when the aux tank is empty, main tank full, main tank half etc. I would like to see the rake float closer to 1"-1.5" with the tanks full and standard passenger load. Hopefully the airbags will accomplish that and slightly firm up the ride at the same time. Should be fun to play with.

 

[CharlieS]

I have the 12.5 LRA and 2721 OME springs. TJM front bumper and winch; Budbuilt step sliders and skids; fully loaded cargo drawers. And King 2.5 suspension. I haven't had any of the issues you describe, but I only occasionally tow small trailers, and only use a hitch mounted cargo tray to fill gas cans locally (not for trips).

 

[21200]

I have the 12.5 LRA and 2721 OME springs. TJM front bumper and winch; Budbuilt step sliders and skids; fully loaded cargo drawers. And King 2.5 suspension. I haven't had any of the issues you describe, but I only occasionally tow small trailers, and only use a hitch mounted cargo tray to fill gas cans locally (not for trips).

Not knowing the spring rate of the Bilstein lift springs makes things a little more complicated. If I had to guess, I would say they are the same spring rate as the factory spring, just 1.75" taller.
I have really liked the ride of the Bilstein kit until I started adding on more weight. For an otherwise factory 200, the Bilstein kit is fantastic.

 

[CharlieS]

The OME 2721 is progressive, unlike a lot of their springs that are linear rate.

 

[21200]

The OME 2721 is progressive, unlike a lot of their springs that are linear rate.

The reason I haven't considered the 2721 as a solution to this point is I do not believe it will offer enough height to maintain the amount of rake I prefer. If OME and Bilstein lift a stock truck the amount they claim to, the rear end when unloaded will drop .75" if i switch to the 2721 and the truck will be dead level with no load. They may not squat as much when loaded, but they will squat some and I will be taking all of our road trips with a reverse rake which is not good for handling purposes or ideal for headlight use, etc.

I am hopeful the airbag man setup will give me what I am looking for. Factory like ride when unloaded, and the ability to better handle a heavier load on occasion. If it doesnt, I will likely experiment with different springs or spacers in combination with the airbags. Hopefully this topic is useful to someone!

 

[CharlieS]

I spoke with several shops (including Ben at Filthy Motorsports, who specced and built my suspension) and all of them said that the OME charts are not accurate in terms of the amount of lift or lowering.

You can't trust the charts.

I have 2.5" of lift over stock with the 2721 OME in the rear and the setup I described above.

YMMV, do whatever works for you. Just sharing a data point. And also, not suggesting that you should use the 2721s, by the way.

I'd strongly recommend talking to a professional, not looking to fools like me on the internet. Ben has built more performance suspensions than I've ever seen, and that kind of experience is invaluable.