Sumo Springs on RV

[BillinTexas]

I recently added Sumo Springs (rubber bumpers) to my truck and what a difference. I have heard of putting them on the RV and was wondering if anyone has done this or something similar and what kind of difference it made.

[Yoda]

I recently added Sumo Springs (rubber bumpers) to my truck and what a difference. I have heard of putting them on the RV and was wondering if anyone has done this or something similar and what kind of difference it made.

Someone has and posted on it. Do a search

[Canyonlight]

I recently added Sumo Springs (rubber bumpers) to my truck and what a difference. I have heard of putting them on the RV and was wondering if anyone has done this or something similar and what kind of difference it made.

Found this thread where drifterranch was going to add them to his Solitude 310 as he noted in post #4. You could follow up with him to get a status report if he does not chime in:

https://gdrvowners.com/forum/operati...opic-discussed

Dan

[Guest]

I recently added Sumo Springs (rubber bumpers) to my truck and what a difference. I have heard of putting them on the RV and was wondering if anyone has done this or something similar and what kind of difference it made.

I took a slightly different approach and added Air Lift air bags to my truck. The action will be similar between these two technologies and that is to progressively slow down the accelerations exerted on your suspension. Especially on bottomless roads in my home state of Michigan. Leaf springs do not have this behavior unless they are progressively stacked with 2nd and 3rd stage auxiliary springs.

What roads do you travel and what truck did you add these to?

Jim

[JeffC]

It's been discussed before as mentioned above by Canyonlight

Adding additional springs/sumo's/air bags on the trailer will not soften or smooth the ride unless you also add some sort of rebound dampening like a shock absorber provides. Without rebound dampening, all heavier or helper springs do is make the ride potentially stiffer and bouncing is increased.

[Guest]

It's been discussed before as mentioned above by Canyonlight

Adding additional springs/sumo's/air bags on the trailer will not soften or smooth the ride unless you also add some sort of rebound dampening like a shock absorber provides. Without rebound dampening, all heavier or helper springs do is make the ride potentially stiffer and bouncing is increased.

Well Jeff, my backside tells me that is not correct for my AirLift System. Mass can dampen vibration which is why most trailers do not use shocks. While lack of shocks is not a perfect solution to trailers, there are some instances shocks (or dampers) could help. For the TV shocks are important but under heavy loading the mass is there as well. Not trying to sell airbags to anyone but they have worked exceptionally well for me. And having spent countless hours on a test track I can tell if the ride quality has changed.
For the sumo springs I have not used them but am open to folks providing feedback on them as well as other devices. Data would be nice, but without that, we should gather enough feedback to see where this goes.

Jim

[JeffC]

Well Jeff, my backside tells me that is not correct for my AirLift System. Mass can dampen vibration which is why most trailers do not use shocks. While lack of shocks is not a perfect solution to trailers, there are some instances shocks (or dampers) could help. For the TV shocks are important but under heavy loading the mass is there as well. Not trying to sell airbags to anyone but they have worked exceptionally well for me. And having spent countless hours on a test track I can tell if the ride quality has changed.
For the sumo springs I have not used them but am open to folks providing feedback on them as well as other devices. Data would be nice, but without that, we should gather enough feedback to see where this goes.

Jim

Hi Jim,

First, I have airbags on my truck and like them because they level the truck when under load and also because I agree that they somewhat improve the ride over stock springs.

But disconnect your shocks and see how it rides then.

The point I am making is that the shocks dampen the rebound forces and the oscillations. I don't think there is any real argument over that. So a properly sprung trailer is one that supports the median load within parameters for sag. Springs/airbags dampen compression forces but not rebound without some sort of additional system, most often shocks.

[Guest]

BillinTexas ,

Can you share what truck you have installed the sumo springs on? Can you provide a picture of your rear spring unloaded as well as loaded with your Transcend ready for a trip?

Jim

[Guest]

Hi Jim,

First, I have airbags on my truck and like them because they level the truck when under load and also because I agree that they somewhat improve the ride over stock springs.

But disconnect your shocks and see how it rides then.

The point I am making is that the shocks dampen the rebound forces and the oscillations. I don't think there is any real argument over that. So a properly sprung trailer is one that supports the median load within parameters for sag. Springs/airbags dampen compression forces but not rebound without some sort of additional system, most often shocks.

Jeff,

For the TV I do not think adding rebound damping is necessary since the air bag or sumo spring will supplement the system where the secondary spring will not be used as heavily, and in some instances the jounce bumpers will not have contact in severe inputs. Thinking half ton truck here. Also as mentioned additional mass adds damping.

For the trailer, and to your point, I would rather add shocks (dampers) than sumo springs alone. drifterranch, has added sumo springs to his trailer and tells us they made an improvement where he was also contemplating adding shocks. His improvement may be due to a reduction in the pitching motion of the trailer and how this response is felt in the TV. Not sure at this point.
I had asked if he could test the shocks alone and again with both shocks and sumo springs. This would provide feedback to us where I suspect the shocks would provide the greater benefit. But this is just an opinion for what that's worth.

Jim

[BillinTexas]

BillinTexas ,

Can you share what truck you have installed the sumo springs on? Can you provide a picture of your rear spring unloaded as well as loaded with your Transcend ready for a trip?

Jim

Sorry Jim, just checking in again. I'll have to see if I can remember to get photos next time I have the trailer hooked up. I put these on a 2018 Nissan Titan Pro4X. Without load, there is about 1" clearance. As mentioned in the OP, the difference is quite obvious. There were two weight models and Sumo advised to go with the lighter if not hauling fulltime and I don't. The vehicle settles immediately after bumps or joints/seams in the roadway. I was amazed at the difference. I had seen some use on trailers on other sites was the reason for my inquiry.

[BillinTexas]

BillinTexas ,

Can you share what truck you have installed the sumo springs on? Can you provide a picture of your rear spring unloaded as well as loaded with your Transcend ready for a trip?

Jim

Jim, here is a photo of each side under load. As mentioned, there is about a 1" gap when not under load. I was advised by SS to use a 1000# bumper instead of the 1500# because I don't drive under load all the time.

[Guest]

BillinTexas Bill thank you. If possible can to take a before and after pick of your secondary spring in relation to the main spring? This would be done at the side of the truck and looking fore or aft of the tire and at the spring pack.

Thinking of two possible cases in why this works so well.

1) The interaction to your secondary spring has changed due to the sumo spring with its own spring rate that works in conjunction with the primary spring. This would be similar to an airbag where with a sumo spring the rate is non-linear where the more you compress, the more resistance to bottoming is applied.
2) The sumo spring may be preventing jounce bumper impact while heavily loaded and when large inputs are encountered such as potholes or uneven road surfaces. Especially on no bottom Michigan roads.

Also some trucks have more or less space between the rear axle and the jounce bumpers and this can become a factor in heavily loaded half tons.

Jim

[BillinTexas]

Jim, I'm not clear on what you are asking to see. The sumo sits on top of the leaf springs which are the stock springs. This sumo model attaches from above and not on the leaf spring as many of them do. The stock bumper I don't think was even half the length of the sumo. I would be surprised if it ever bottomed out even when loaded.

[Guest]

BillinTexas Bill,

Here is an example of my truck unloaded.

To have this pic of your truck loaded as well as unloaded would be great.

Jim

[Country Campers]

Guest

Jim

I see where you are going with the picture question and I am curious as well. I have noticed with our unit while traveling that at certain road conditions I feel the rear suspension on the truck bottom out on the factory "rubber stoppers" and it seems to be a pretty solid hit when it does. This Sumo Springs has been on my mind for a few months this year and this may just seal the deal for me. I am not overweight by no means but the Chevy suspension is pretty "soft" for a nice ride. When loaded I almost am sitting on the helper leaf. This is one thing Ford has always had over Chevy. A camping friend has the same truck I do in the Ford. Although his is soft at the first few hundred pounds it gets stiffer where as the Chevy seems to be stiffer first and then soften as more weight is applied. Maybe this is not the case but sure seems like it.

Brian