"CS-DMRC-14-R1" vs. "CS-DMRC-14-R2"

Two springs to meet the needs of any Carli-Equipped 2014+ Ram 2500!


R1: The perfect complement to an unloaded truck with custom-tuned Carli shocks. Ideal for customers desiring a level appearance (with their Carli 3.25″ System) and the BEST ride with capability up to 1,500lbs of bed-load.

R2: Suited to the customer wanting to maintain the payload capacity and factory rake (unloaded) willing to accept a slightly firmer ride vs. the R1 (it is still softer than OEM rear springs). OR – The customer looking for the best ride and level appearance when loaded with a constant 800lbs (i.e., Overlanders).

I know what you’re thinking… There are two options? The “R1” is the production Carli Spring designed to optimize the unloaded 2500. This is the rear spring we’ve include in all systems since late 2015. Want to know which spring you have? Take a look at the printed Carli logo on the coil, it will be accompanied by a part number.

The pictured coils carry an “R2” designation. These have existed as long as the R1 but have been a “secret menu” item until now. The “R2″ springs are 1” taller than the “R1” at ride height – by “ride height” we mean under load, not free-standing. So, with the weight of your truck on the springs, there will be a 1″ height difference. You can see below, the R2 Coils are actually shorter than the R1 when free-standing!

To touch on some basics of coil design, there are many considerations when blueprinting a spring. When adding 1″ to the ride height, one can’t always increase the length of the spring by the amount of wire needed to achieve the loaded height desired as there are often constraints. In this case, the solid height of the coil spring is the limitation. The solid height of the coil is the dimension at which ALL winds of the coils are fully compressed and in contact (bind). If this length exceeds the height between spring buckets with the axle fully compressed (bump stops resting on the axle), then the rear bump stops need to be relocated to compensate for the longer spring.

The Carli 3.25″ Systems run a 1″ bump drop to accommodate both the longer shock and longer spring we offer. Given we’re maxed on compressed spring dimension with the R1, we chose another route to increase the loaded height of the spring. The spring rate was increased by increasing the pitch of the coil (you can see how much steeper the R2’s secondary rate is vs the R1 in the above comparison picture) and, we utilized a larger wire diameter, pictured below.

R1

R2

TEST TRUCK

2022 Ram 2500, 4×4, 6.7L Cummins Limited

3.25″ Carli Pintop System – R1 Rear Coil Springs

Torsion Sway Bar

Low Mount Steering Stabilizer

Method NV, Matte Black, 20×9 | +18mm Offset, 5.75″ Backspacing

37×12.5r20 Toyo RT

MEASUREMENTS TAKEN

Ground to Center of Fender-Lip: This measurement is “rough”. When measuring from ground, around a tire to a tapered fender flare with a round lip, one cannot expect precision but it is plenty-good to understand the points portrayed within. We’re not measuring precise lift-height changes – rather demonstrating the effect of varying bed-loads and their rear “sag” relative to the front of the truck. Don’t get too hung up on the height listed here as your measurement will vary based on tire size & pressure. Most important here is the listed “Stance” and “Bump Measurement”.

Bump Measurement: This measurement will come in once we get deeper into the article as it determines how “usable” the spring is. Understand that the factory bump stops will compress and the suspension is designed to work all the way to metal/metal contact so, although these measurements seem short, the truck is actually quite usable even in this squatted stance. We like to maintain at least 0.75″ – 1.25″ at this measurement.

UNLOADED

In the Unloaded test, the bed was empty. This truck had a factory spare under the bed, a Retrax Cover and some cross bars – nothing notably heavy that would affect the rear height.

Aesthetically, the R1 coil provides a level appearance but measurements put it ever-so-slightly rear-high. The R2 Coils are noticeably rear high and, from the listed measurements, you can see the additional rear lift actually pushed the front down 1/8″ relative to the R1.

UNLOADED R1 R2
Front 45.125″ 45″
Rear 45.5″ 47.125″
Stance 0.375″ Rear High 2.125″ Rear High

500 LBS

Our 2003-12 Ram 2500/3500 6″ lift springs clock in right at 100lbs when boxed. We stacked (5) of these directly over the axle for this measurement.

The R1 coil sags noticeably with 500lbs in the bed; the rear end dropped 1.375″ at the fender from the previous measurement exaggerated by the 1/8″ lift on the front coil. This test reveals just how soft the initial rate of this spring is. The R2 dropped slightly less at 1.125″ while lifting 3/8″ in the front. Regardless, the R2 retained a rear-high stance.

500 lbs. R1 R2
Front 45.375″ 45.375″
Rear 44.125″ 46″
Stance 1.250″ Front High 0.625″ Rear High

1,000 LBS

At the 1,000lb load, we’re introducing the “Bump Measurement” for the R1 coil as it is starting to show significant sag. The R2 shows no stress so we’ll save it for 1,500lbs.

Again showing its lighter rate, the R1 coil sags considerably with the 1,000lb. load dipping another 1.5″ from the addition of the second 500lbs. The R2 shows, and measures, a perfectly level stance with the 1,000lbs only dipping 3/4″ from the same 500lb addition. The R2 is now showing the resilience of the secondary rate of the coil dropping only half as much as the R1 from the additional 500lb load.

1,000 lbs. R1 R2
Front 45.375″ 45.25″
Rear 42.625″ 45.25″
Stance 2.75″ Front High LEVEL
Bump Measurement 1.5″

1,500 LBS

1,500lbs marks the capacity of the factory Power Wagon but still about 500-1,000lbs under that of a standard 2500. At this point, we’re introducing the Bump Stop measurement as we’ve maxed the “R1” Spring with this load.

The R1 dropped another 1″ from the additional 500lbs and has reached its limit. The rear is still usable as the rubber bump stop floats 3/4″ over the axle (again, remember this can compress a couple inches into the bump stop) – but the appearance is that of a max-loaded truck. The R2 Dropped 7/8″ and is now front high, per the measurements, but hasn’t yet broken a sweat!

1,500 lbs. R1 R2
Front 45.5″ 45.25″
Rear 41.625″ 44.375″
Stance 3.875″ Front High 0.875″ Front High
Bump Measurement 0.75″ 3.5″

2,000 LBS

The R1 has tapped out – its supple nature has been bested by the heavy-weight contender. The R2 was loaded with another 500lbs and dipped 3/4″ from the weight. Still floating nearly 3″ from the bump stop contacting, the coil remains perfectly poised with the load.

2,000 lbs. R2
Front 45.25″
Rear 43.625″
Stance 1.625″ Front High
Bump Measurement 2.875″

2,500 LBS

Throwing another 500lbs to hit the highest payload of the Ram 2500(s) – 2,500lbs.

With the final 500lbs dropping the rear another 5/8″, the R2 coil has proven its ability to hold weight. Even bearing a load that slightly exceeds the factory payload of most well-equipped Ram 2500 4×4(s), the R2 remain minimally squatted. The secondary rate of this coil is a workhorse! We stopped the loading here but this spring could easily take another 500lbs before it sagged to the same level as the R1 with 1,000lbs!

2,500 lbs. R2
Front 45.25″
Rear 43.0″
Stance 2.25″ Front High
Bump Measurement 2.25″

LOAD SUPPLEMENTS

We get the question all the time… Will i need airbags? Ram has complicated the HD platform beyond the scope of any other brand. There’s a 2500 that rides well (Factory Rear Coils), a 2500 that hauls well (Factory Rear Airbags). A 3500 that hauls OK (Factory Rear Leaf Springs) and a 3500 that hauls amazing (Factory Rear Traction Leaf + Airbags).

Far and away, the 2500 with rear coils is the most prevalent, at least, among our customer base. The R1 spring optimizes this platform but, as detailed above, they’re not heavyweights. Coming from a factory coil that’s lackluster in its ability to haul, this shouldn’t be much of a surprise.

So what’s the deal, R1 + a load supplement or R2? Well, let’s run over the options for load supplementation with the R1.

AIRBAGS

You can run airbags with any of our systems but the 2500 (with coils in the back) is the least accommodating to airbags. Most of the widely available airbag systems replace the bump stops, mounting between the frame rail and axle. There are other options but they’re outboard the frame leaving them VERY susceptible to road-debris or failure from a tire related issue.

Back to the common kits that mount between the frame and axle – the collapsed dimension of the airbag kit is about 2-3x the size of the bump stops they replace. In turn, you’re sacrificing substantial up-travel to run the airbags, usually 3-4 inches. Around town, you won’t likely notice if the bags are empty. Hit a culvert or obstacle over a couple inches and you’ll hit pretty hard out back when you bottom out on the airbag.

Airbags are nothing more than a necessary evil in any platform and will always detract from ride quality (to varying degrees). That said, the infrastructure of the rear coil spring 2500 is the most affected by the negative effects of airbags. Run them with the Daystar Cradle and you’ll minimize their effect on down-travel (holding travel) and have all the capacity you need within the capability of the truck at the expense of substantial up-travel – although, the Daystar cradles take away an additional 3/4″ of up-travel, as well.

TIMBRENS

These hollow-rubber springs replace your factory bump stops hovering the axle 0.50″ to 1.5″. When they hit the axle, they hold the load. As these rubber springs are designed to hold a load, they will eliminate MOST of your up travel in favor of their “spring rate” assisting the suspension in handling the load. We recommend swapping these in ONLY when hauling/towing or you’ll be bouncing off them over every little bump in the road.

These are ideal pairing to the R1 for the customer hauling a few times a year that doesn’t mind spending 20 minutes to swap the bumps for the Timbrens on the rare occasion they’re needed.

CONCLUSION

R1

We’ve been running both these coils since 2015 – more customers seem to err toward the R1 as they’re exactly what one seeks from a performance suspension on a mostly-unloaded truck; less spring rate to better balance the unloaded rear end to the heavy front while pairing perfectly to Carli’s custom-tuned lineup of high-end shocks. These coils max around 1,000lbs bed load but can be pushed to 1,500lbs if kept to the pavement. At this load, you’ll experience significant sag but that’s the cost of running a super-light spring.

R2

Conversely, there’s the customer more focused on utilitarian use. As outlined, loading near capacity presents a unique challenge on this platform when Carli equipped, thus, it made sense to offer a higher capacity coil. The R2 definitely firms the ride and adds rear-rake when compared to its lighter-rate counterpart; however, it is not as jarring as one might think as the initial spring rate masks the rate transition. The real capacity comes from the secondary rate ensuring users that select this coil still see a marked improvement in compliance over the stock spring. We’ve yet to hear from any customer dissatisfied with the unloaded ride after swapping to the R2 from the R1 but, there’s no arguing the R1 will provide a better ride and off-road performance while the R2 shines in its compromise between compliance and capacity.

The explosion of the Overlanding market continues to increase customer calls seeking constant-load springs. The ability to support an 800lb constant load, while leveling to our 3.25″ systems, perfectly suits those with aftermarket rear bumpers, racks, spares and roof-top tents. These are NOT for those with slide-in campers approaching the capacity of the truck but for those looking to throw a heavy-duty twist on their utilitarian style build equipped with one of our performance suspensions!