SumoSpring Installation Report and Review

Suspension issues can really take the fun out of truck camping. Things like rear sag and porpoising to sway and bumps from uneven roads can be a real drag. Unfortunately, correctly matching your camper with your truck doesn’t guarantee a quality, stress-free ride. This is because a truck camper can create all kinds of issues regardless of whether its under or over your truck’s GVWR. There’s no doubt about it. Correctly matching a truck camper with a truck is just phase one—phase two is getting the ride of the truck and truck camper camper combo just right. One of the better engineered products that addresses these annoying, potentially damaging suspension issues is a product called the SumoSpring, a product made by SuperSprings, an American company based out of Carpinteria, California.

The SumoSpring is a hybrid, a revolutionary suspension product that performs several important functions rather than just one. On one hand the SumoSpring works like a standard bump stop, on the other hand like an air spring or air bag. Unlike an air bag, however, the SumoSpring doesn’t require compressed air to work. Instead, the air found in each SumoSpring is contained within the rubber compound itself, which consists of a proprietary closed-cell micro-cellular urethane. This durable, “closed cell” construction results in a ride that is less harsh on the road than standard rubber bump stops, yet smooths out the “rough edges” of travel like a good set of air bags. If you’ve ever encountered a surprise hole or bump in the road or an unusually rough railroad crossing, you know how important this feature can be.

Comparison between the Rebel SumoSpring left and Timbren SES bumpstop right used on the rear axle.

But the SumoSpring does so much more when it comes to supporting your truck and camper. Like a shock absorber, it also provides additional damping properties for your rig. The progressive property of the spring means you get more support when hauling a truck camper, less support when you’re not. Furthermore, SumoSprings reduce side-to-side body roll, resulting in a more stable, safer driving experience like a sway bar. Moreover, SumoSprings are maintenance-free, will not leak, and do not require airlines or compressors, meaning SumoSprings are much easier to install and maintain than standard air springs.

The maintenance-free aspect about the SumoSpring deserves more than just a mere mention. While the Air spring is an excellent option for truck camper owners looking for an adjustable solution, not everyone needs an adjustable solution and the complexity and maintenance associated with it. This is because many truck camper owners keep their campers on their trucks full-time or close to it. This is where the beauty of the SumoSpring really shines. Like a standard bump stop, it’s always there, on-call, ready when you need it. Just install it and forget about it. No air pressure checks are needed. We had an air bag fail once on the road—a Firestone Ride Rite—and it wasn’t fun. With the SumoSprings you never have to worry about that happening on your outings.

SumoSprings are offered in a variety of heights, diameters, and densities to accommodate various loads and work, including offerings for both front and rear axles. Distinguished by color, SuperSprings offers three different densities of rubber: yellow, black, and blue. Blue SumoSprings provide the least amount of support, black a moderate amount, while yellow offers the most support (we decided to go with the black Rebel on our truck). Three different types of SumoSprings are also offered, called the Rebel, Maxim, and Solo. Obviously, getting the right density of SumoSpring is important because the SumoSpring isn’t adjustable like an air bag. More about this important topic later. The cost for a pair of Rebel SumoSprings is about $470; a pair of Solo Sumos about $200.

Solo SumoSprings used on the front axle.

The design of the Rebel SumoSpring used on the rear axle is clever in its simplicity. The Rebel comes in two-pieces, consisting of separate male and female pieces that interlock and work together when compressed under a load. The beauty of this approach is that the design allows unrestricted wheel travel and will not affect the ride of your truck when the camper is unloaded, a HUGE plus. Moreover, unlike the standard sway bar, rear axle flex is in no way hindered by the SumoSpring, another plus for those who like to take their rigs off-road.

Of course, suspension modifications like the SumoSpring will neither increase the Gross Vehicle Weight Rating (GVWR) nor raise the payload capacity of your truck. The SumoSpring is designed to enhance the vehicle’s road handling and load carrying performance only. In other words, it should not be used to address a woefully inadequate GVWR and payload rating of your truck. If you need more payload, buy a truck with a larger GVWR.

SumoSpring fully compressed with the camper loaded.

SumoSpring Installation

I like to learn how things work and the best way to do that is to do the installation yourself. For our 2013 Ram 3500, we installed black Rebel SumoSprings on the rear axle, while blue Solo SumoSprings are installed on the front. On a scale of 1 to 10, I’d have to give the Rebel SumoSpring installation a solid 3. It’s pretty quick and simple. Anybody handy with a wrench can do it though you’ll need a floor jack to lift the frame of the truck up several inches. This extra clearance is needed to perform the installation, which includes mounting the Rebel SumoSpring top to the frame rail and the Rebel SumoSpring bottom to the axle. The instructions were clearly written and easy to understand with no “gotcha” moments or need to call the SuperSprings hotline to get installation answers and advice. Overall, the installation took a good two hours for both springs not including the time it took to remove the OEM bumpstops. Oh, while you’re at it, be careful not to pinch the brake lines when installing the axle assemblies.

Rebel SumoSpring fully installed on a Ram 3500 4×4 truck.

As for the front axle, you’ll be happy to know that installing the Solo SumoSpring is even easier. Overall, I’d have to give the difficulty a difficulty rating of 1. With the exception of a floor jack, no tools were needed for the job, simply wedge them into the existing bump stop hole by hand, a process that takes only a few minutes. The best way to approach the installation is to install them from the back. There’s more elbow room that way. It goes without saying that you’ll spend more time jacking up the front of the truck than installing the Solo SumoSprings. It’s that easy.

Installed Solo SumoSpring on the front axle.

How They’ve Performed

Since installing the Rebel SumoSprings, we’ve been deluged with inquiries on how they’ve worked on our new Bundutec Roadrunner truck camper. As stated in a recent article, the fully loaded weight of the Roadrunner is 3,300 pounds, heavy but within the payload rating of our truck. Have the Rebel SumoSprings been a good fit for the weight? That’s a great question since SuperSprings sells three color densities based upon the weight of the truck and the truck’s load. The black density Sumo seems to be a good fit without too much of the “boinga-boinga,” rebound effect going over bumps and dips in the road. Some think that going with a softer, blue density Sumo would be a better fit for a fully-loaded camper slightly below the truck’s GVWR. That’s hard to say without giving them a try. We can say that we’ve been extremely happy with the performance of the black-colored Sumos. They provide just enough cushion for bumps and other imperfections in the road while at the same time keeping the rig level and even on turns. Overall, we definitely like the SumoSprings better than the Timbrens and we gave the Timbrens a high rating in a review several years ago. Performance wise, we’d say the Sumos break even with the Hellwig Big Wig Air Springs. That’s a plus in our book because of the no-maintenance design of the Sumos.

As for the Solo SumoSprings in the front, we have to say they’ve been a revelation. At first, we were kind of resistant to getting them, thinking that we really didn’t need them. But the SuperSpring rep insisted and we’re glad we listened. As you know, the front axle takes the initial brunt of any bump or hole encountered and the Sumo Solos have been terrific in cushioning such blows. We encountered one particularly rough railroad crossing in western Kansas that totally caught us by surprise. The SumoSprings on the front axle really saved our bacon and prevented who knows what kind of damage from occurring to our rig. Of course, the real benefit of having the Solos on the front axle is that they can give you enough time to adjust your speed to reduce the impact on the rear axle, but only if you’re going slow enough.

Minuscule Ram 3500 OEM Bumpstop

SumoSpring Verdict

It seems like truck campers owners are always on the lookout for the perfect suspension product—one that keeps the rig level and eliminates sway while at the same time providing the rig with a soft and smooth ride. Finding products that can do these things is important as it improves the overall driving experience and protects the truck and camper from the rigors of the road. In the past, we’ve had to accomplish these tasks with two or three products. With the SumoSpring, you only need one. This greatly simplifies the search for truck camper newbies, reduces cost since only one product is needed, and simplifies overall installation and maintenance. Yes, you still need to take challenging road surfaces cautiously and a little slow, but with the SumoSpring it’s nice to know that you have an “insurance policy” when it comes to softening your ride and protecting your investment. What would we rate the SumoSpring? On a scale of 1 to 5 with 1 being the lowest and 5 being the highest, we give the SumoSpring a rating of 5 stars. The SumoSpring is the ultimate truck camper suspension product and comes with our highest endorsement.

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About Mello Mike 534 Articles
Mello Mike is an Arizona native, author, and the founder of Truck Camper Adventure. He's been RV'ing since 2002, is a certified RVIA Level 1 RV Technician, and has restored several Airstream travel trailers. He currently rolls in a 2013 Ram 3500 with a 2021 Bundutec Roadrunner truck camper mounted on top. He retired from the U.S. Navy in 2004 as a CWO3 after 24 years, worked in project management, and now runs Truck Camper Adventure full-time. He also does some RV consulting, repairs, and inspections on the side.

7 Comments

  1. Thanks much for this in-depth review of Summo Springs and your earlier review of Timbrens. Question: in your Summo Springs review, you say that you definitely prefer the Summo over the Timbrens, but you don’t say why; could you please explain?

    The reason I ask that I’m looking to add a suspension upgrade, so your insight and experience would be super helpful.

    I have a 2020 Ram 1500, and will put an Outfitter Caribou Lite 8 on next spring that will stay on the truck 99% of the time. Wet weight of the camper plus food and gear will put me right at the factory SAE official payload max of 1710 lbs (this already includes 300 lbs of people weight and the weight of a full tank of gas). I was thinking of replacing the OEM springs with Tuftruck 1210 coils that are rated to increase capacity 25% to eliminate sag and improve dynamic stability. Would these coils provide the exact same function as Timbrens/Summos or do they provide different functionality so it would be worthwhile to add both? I’m new to the world of truck campers, so any insight others could offer would be greatly appreciated about coils and/or Timbrens (or Summos).

  2. We were very interested in SumoSprings for our rig until we read they were not recommended for use at temperatures below -25F (-33C). Where we are in Canada, those kind of temperatures are occasional but inevitable 🙁 Not mentioned in the literature is what happens to the product at those temps and would it be safe if your vehicle was parked.

  3. Mike – I had these sitting in my garage and your review inspired me to put them on. I agree the install is pretty easy — I took wheels off for easier access. Hardest part for me was getting the truck jacked up high enough and safely (with camper off).

    My 3500 is a gasser and the OEM bumpstops front and rear were pathetically small. In fact, even with all the off road miles I have put on, none of them look like they have ever been impacted.

    Looking forward to the rally and the run after,

  4. Mike,

    These sound great. I am likely getting them for both the rear and the front axles on our 2006 Silverado 3500. There is NO WAY I would try to install them myself, I am well known for not being able to get a lug nut off! They are available on Amazon but the descriptions are so incomplete – I guess they are sold in sets, but do they include the top and bottom mounting plates? Two ways I could go, buy on Amazon and have Les Schwab install, or buy from Paulsbo RV, which is listed as one of the retailers and have them install. I am waiting for a quote from Paulsbo. Is there going to be another Boondocking in the Desert at Quartzsite again this year? We may or may not be coming down this year due to knee surgery. But it was a lot of fun last year.

    Pat (and Patty) Anderson
    2017 Alaskan 8.5 CO

  5. One thing you invariably find when searching the Internet regarding suspension enhancements is there is simply no agreement as to which mods or add-ons do what and the reasons for the confusion are many.

    First off, it strikes me many reviewers are posting ratings after running with very few miles and some with no road miles at all after making as suspension change.

    Secondly, there no true as head-to-head comparisons are done for practical reasons like money and time swapping equipment. That means the comparative standard against which improvement is measured is often based on one’s imagination.

    Third, I think most of us tend to defend our buying decisions, That makes for a real scarcity of negative comments from owners about things they purchase and frequently negative statements about something they never owned.

    Finally, how does one really compare suspension modifications in truck camper when trucks models and camper models offer an almost infinite number of permutations and combinations? Does what works with a Lance on a Dodge work with an Adventurer on a Ford? Maybe, but maybe not.

    I bought Sumo according to the weight recommendations on their website and it felt like I basically bolted on a bigger stiffer bump stops and when I contacted customer service I was advised to buy another set at a lighter weight rating. No responsibility at all for what they recommended.

    I made myself a set of what would be comparable to Torklift uppers for about $20.00 and the improvement in handling and ride comfort was remarkable on our Ford F350 SRW LB. Someone else might buy a set and have the exact opposite reaction. Then again someone might say I should have “bagged” my truck from the git-go.

    For a time I used to evaluation suspension systems and after-market add-ons for motor homes and what I took away from those sessions was basically this.

    Choosing a single component would normally result in a dramatic improvement in handling without doing anything further. However, figuring out what that single best component was was anyone’s guess. You just had to roll the dice. 🙂

    Ardvark

  6. 3 things kept me away from sumusprings (and pushed me towards tork lift upper stableloads. I read several reports of them cracking in cold weather. The response from the company was buy a different set! (You won’t hear that from Torklift) and many reports of people loving the front springs for about 6 mos-a year until they compress and stop working. Keep us posted. So far I’m very happy with my choice in all regards but I would like some additional lift and
    cush in the front too.

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