Sumo Spring choices

[Dana H]

I've been looking into the Sumo Springs for our truck to help improve the ride and minimize the bounce.
First of all I feel as though the the WDH is well tuned.
Towing the TT I have minimum sway issues and otherwise quiet satisfied with the overall handling.

The truck's rear typically drops about 1-3/8"
The trucks front rises about 1/8"
The tongue weight is typically around 960# (13%)
These are the actual Cat scale results.

The truck is still on the original P rated tires which I run at 5# higher to increase stiffness.
When it becomes necessary I will replace with higher load rated tires, probably Nitto.

The normal ride of the truck without the TT is very comfortable.

I believe the short wheel base contributes to bounce/rebound.
This was all more noticeable on our last trip which the longest to date of ~1700 miles'

After researching and searching the archive here I sort feel that the SUMO Springs may be the way to go to improve the ride.

While they come in 3 sizes I believe the Yellow will be too stiff for my application.

The Black seem to be the probably choice but I'm a little concern that it may stay energies to some extend with out the TT and create a stiffer "normal" ride. They are rated for 1500# @ 50% compression and with the 960# tongue being roughly 64% of its capacity. While I did contact Sumo they simply said stated the Black would work.

The Blue is rated for 1000# @ 50% compression. With that said I'm leaning towards this one.
I seems like it is less likely to affect the normal ride without the TT but still be in range to handle the addition lounge weight of 960#, but that puts it @ 96% of it's rating.

There is one piece of data that I think would be beneficial is what would the height of the compressed Sumo Spring when loaded with the TT. I would expect it to compress an additional 1- 3/8" but don't really know where that is in relationship to the spring height with no extra weight on it.

With that I would like to ask the list for their experience/guidance.

BTW I looked at the air bag systems and RAS system and didn't feel that my issues fell into either one of these options.

[Dutchman2]

I've been looking into the Sumo Springs for our truck to help improve the ride and minimize the bounce.
First of all I feel as though the the WDH is well tuned.
Towing the TT I have minimum sway issues and otherwise quiet satisfied with the overall handling.

The truck's rear typically drops about 1-3/8"
The trucks front rises about 1/8"
The tongue weight is typically around 960# (13%)
These are the actual Cat scale results.

The truck is still on the original P rated tires which I run at 5# higher to increase stiffness.
When it becomes necessary I will replace with higher load rated tires, probably Nitto.

The normal ride of the truck without the TT is very comfortable.

I believe the short wheel base contributes to bounce/rebound.
This was all more noticeable on our last trip which the longest to date of ~1700 miles'

After researching and searching the archive here I sort feel that the SUMO Springs may be the way to go to improve the ride.

While they come in 3 sizes I believe the Yellow will be too stiff for my application.

The Black seem to be the probably choice but I'm a little concern that it may stay energies to some extend with out the TT and create a stiffer "normal" ride. They are rated for 1500# @ 50% compression and with the 960# tongue being roughly 64% of its capacity. While I did contact Sumo they simply said stated the Black would work.

The Blue is rated for 1000# @ 50% compression. With that said I'm leaning towards this one.
I seems like it is less likely to affect the normal ride without the TT but still be in range to handle the addition lounge weight of 960#, but that puts it @ 96% of it's rating.

There is one piece of data that I think would be beneficial is what would the height of the compressed Sumo Spring when loaded with the TT. I would expect it to compress an additional 1- 3/8" but don't really know where that is in relationship to the spring height with no extra weight on it.

With that I would like to ask the list for their experience/guidance.

BTW I looked at the air bag systems and RAS system and didn't feel that my issues fell into either one of these options.

Look into Tembrens as well. Standard ride quality unloaded as the rear bump stops are not in contact with the axel. We have been very please with loaded ride results. Super easy install @ 30 minutes for both sides.

Dutchman 2

[Conner58]

Have sumo springs yellow ones . Put on before we got or 5th wheel so can't tell you any difference.
The ride is good very happy with them .
They are adjustable for engagement i have about 3/4 before they touch. I can't tell empty if they hit over bumps or not.

[Dana H]

I did look into these but since there is a gap of almost 3" unloaded and I would anticipate it closing within 2" once the TT is attached in my case, so it will act similar to what it is now with just the OEM bump stop but with the extra resistance/capacity built in.
With the Sumo springs it appears there is little to no gap (my truck has a 7" gap between axle and frame. The blue have a 4" height plus a bracket that I'm not sure of the overall height.)and the capacity increases as it gets compressed. So in my mind the Blue would be my choice to absorb the bounce with out getting to stiff so they work to soften the bounce. The Blacks have more capacity so that may lead to a too stiff ride, as compared.

According to my calculation based on the CAT scales is there is about 600# more weight on the rear axle with the WDH engage oppose to not engage. Providing I'm interpreting this correctly:
With WDH ENGAGED based on CAT Scales:
Steer axle: 3520#
Drive Axle: 3560#
Trailer Axle: 6820#
Total Axle: 13900#
WITHOUT WDH engaged based on CAT Scales:
Steer axle: 3120#
Drive Axle: 4160#
Trailer Axle: 6660#
Total Axle: 13940#


And I'm not sure if their characteristics are different on a travel travel bumper pull as opposed to a 5th wheel setup. I'm new to camping and towing, a 2 year old.
Appreciate your feed back

[Calbar]

Look into Tembrens as well. Standard ride quality unloaded as the rear bump stops are not in contact with the axel. We have been very please with loaded ride results. Super easy install @ 30 minutes for both sides.

Dutchman 2

I second Timbrens. I have them on my 3500 for towing the 5th wheel and unloaded ride is not changed but they handle the heavy pin weight very well. Also only took me 10 minutes to install. I originally ordered Sumo Springs and turned out to be a !@#show because they didn't fit properly into the unbolts even though Sumo Springs insisted that it didn't matter. Sumo Springs would have been much harder to install even if they would have fit as they should have.

Rob


Rob

[Slappy]

I ran Timbrens first, then replaced them with yellow Sumos.

Tow vehicle is a 2019 F350 4x4 SRW Long bed CC

Unloaded, they do not touch the bump stop shelves, so there is no affect on ride.

Loaded, the Timbrens seemed more firm, and are more of a replacement to the factory overload springs.

Loaded, the yellow Sumos are more of a supplement to the factory overload springs.

Thats how I sum it up.

[MoonShadow_1911]

I put the black Sumo Springs on my 2019 F-350 crew cab long bed. The frame does rest on them, but has made my towing experience so much better. Unloaded, bumps do transfer to the cab.

EDIT: I have blue Sumo Springs on the coach.

[Soundsailor]

The Timbrens are on the truck, and the Sumo Springs (blue) are on the coach. A good combo for me.

[Slappy]

I put the black Sumo Springs on my 2019 F-350 crew cab long bed. The frame does rest on them, but has made my towing experience so much better. Unloaded, bumps do transfer to the cab.

Sounds like you put spacers in??

I have the exact same truck as yours and mine have air under them

[MoonShadow_1911]

Sounds like you put spacers in??

I have the exact same truck as yours and mine have air under them

No spacers. Mine is also a 4x4.