sumo springs - little review

[silver billet]

I haven't seen much information on this forum regarding these helper springs. I have a trailer + WDH that is sitting level, but the stock shocks feel to bouncy while driving, and the bounce is what I'm trying to reduce, not trying to carry more than my payload.

So I purchased the sumo springs, the medium/black ones rated at 1500 pounds:
SSR-307-47

Installation is straightforward to understand. Jack/block up the truck a few inches using the hitch, keep the rear wheels on the ground, chock off the front so it doesn't roll. Then crawl underneath and pull out the factory bump stops with your hands, and then put Sumo springs in their place. Lower truck, and the springs will touch the axel when jack is removed.

Which brings me to the problem I have; they have COMPLETELY transformed my unloaded ride quality, and in a very bad way. I feel like I'm driving a 3500 now, my head is bopping up and down and back is jerking around. Have not yet connected my RV (4000 pounds), but very unhappy with them at this point. All the information I read was that they were supposed to be unnoticeable when truck is unloaded, so factory shock feeling. This is not true at all. I could feel the difference instantly, even just driving down my gravel driveway and going through the pot holes in first gear.

The springs do come with a spacer that can be removed. I may try that, the spacer is about 1 inch or so, my concern is that with a load on the back, there may be an air gap still until you hit a bump, and then at that point when the sumo springs touch the axle there might be a very noticable "hit".

Perhaps I ordered the wrong model. I might need the blue ones. Next week I tow my trailer 4 hours, so I will have another update at that point.

 

[LoNeStAr]

Is the spring sitting on the axle without anything loaded in the bed? If so you definitely need to remove the spacer. You need 1 inch gap to still have the stock ride. Can you post a pic?

 

[silver billet]

Is the spring sitting on the axle without anything loaded in the bed? If so you definitely need to remove the spacer. You need 1 inch gap to still have the stock ride. Can you post a pic?

The sumo spring is on the axle, but the ram-specific instructions show the spacer installed. I also called them up after posting this and they said it's user preference, but I think I will take the spacer out tomorrow and see again. Agreed that there needs to be an air gap in order for stock ride, but my worry is what happens when you pull a trailer/light fishing boat that is just enough to bring you above touching, but every little bump then makes contact? The ride quality at that point must be horrid as you feel the jar of the connection on each bump.

My hope was that by having no gap, the progressive spring would slowly work as weight is added, while maintaining next to stock feel with nothing in the bed.

I will post some pics tomorrow if you still want them, it's dark right now.

 

[LoNeStAr]

The progressive spring needs weight to work. So having a 1” gap will allow stock ride but once you add weight even with a light fishing boat should engage the springs since the springs that come on the truck are soft.

You are still going to feel a stiffer ride on larger bumps but that is going to be part of the trade off.

If you can take some pics tomorrow it would be appreciated. I am still trying to decide between Sumo and Timbren

 

[Curlymurt]

Definitely interested to hear how the tow goes.

 

[LoNeStAr]

The sumo spring is on the axle, but the ram-specific instructions show the spacer installed. I also called them up after posting this and they said it's user preference, but I think I will take the spacer out tomorrow and see again. Agreed that there needs to be an air gap in order for stock ride, but my worry is what happens when you pull a trailer/light fishing boat that is just enough to bring you above touching, but every little bump then makes contact? The ride quality at that point must be horrid as you feel the jar of the connection on each bump.

My hope was that by having no gap, the progressive spring would slowly work as weight is added, while maintaining next to stock feel with nothing in the bed.

I will post some pics tomorrow if you still want them, it's dark right now.

Any luck removing the spacer?

 

[silver billet]

Any luck removing the spacer?

Just sat down for dinner, but yes, almost done the swap, have 2 bolts left to tighten. Between the 2 springs, there are 16 nuts total, and some of them are a royal pain to tighten down as there is very little room to maneuver my box wrench; think 1/16'th turn, lift wrench, move back, put wrench back in and turn another 16th etc etc. My neck is aching as I've been under there a while (first pulling them off, and now putting them back in). I'll post another update when I'm done.

 

[LoNeStAr]

Just sat down for dinner, but yes, almost done the swap, have 2 bolts left to tighten. Between the 2 springs, there are 16 nuts total, and some of them are a royal pain to tighten down as there is very little room to maneuver my box wrench; think 1/16'th turn, lift wrench, move back, put wrench back in and turn another 16th etc etc. My neck is aching as I've been under there a while (first pulling them off, and now putting them back in). I'll post another update when I'm done.

Take some pics of the gap between the spring and the axle once you take it off the jack if you don’t mind

 

[silver billet]

With the spacers removed, there is a very small air gap now. Ride is much better, but still not back to stock. Small ripples in the road are fine, but larger road bumps or construction potholes etc, definitely feel that jar. I will see how they work when towing my trailer.

I suspect I should have gotten the blue ones, the lighter grade. Technically speaking I don't need springs, my truck sits perfectly level with my trailer when WDH is setup, so the idea was just to remove some of the bounce that coil suspension brings under load. So really, I just need to "take off the edge" rather than full on suspension support.

Pictures below are spacers removed, and truck is sitting level with jack removed.

 

[dougf]

The progressive spring needs weight to work. So having a 1” gap will allow stock ride but once you add weight even with a light fishing boat should engage the springs since the springs that come on the truck are soft.

You are still going to feel a stiffer ride on larger bumps but that is going to be part of the trade off.

If you can take some pics tomorrow it would be appreciated. I am still trying to decide between Sumo and Timbren

I also considered both the Timbren and the Sumo, but finally settled on the Timbren. Installed, there is about a 1" gap over the axle. Pulling a trailer with ~700 lbs tongue weight, they made a big difference. Especially noticeable was the stiffer ride over the larger bumps on the highway. Overall, they just gave it a larger truck feel. I doubt they are any better or worse than the Sumo, but without question easier to install. No tools necessary. I did it with the trailer attached to the hitch (I was already hooked up when UPS dropped them off.) I raised the trailer to pull the bed of the truck up a couple inches. Then, it was just a matter of pulling the OEM bumper stops out, putting a little soapy water on the Timbrens and forcing them in as far as I could by hand, and then lowering the trailer. It pushed them right in. Total time was no longer than 15 minutes. Without a load, I don't notice any difference in the ride.

 

[LoNeStAr]

With the spacers removed, there is a very small air gap now. Ride is much better, but still not back to stock. Small ripples in the road are fine, but larger road bumps or construction potholes etc, definitely feel that jar. I will see how they work when towing my trailer.

I suspect I should have gotten the blue ones, the lighter grade. Technically speaking I don't need springs, my truck sits perfectly level with my trailer when WDH is setup, so the idea was just to remove some of the bounce that coil suspension brings under load. So really, I just need to "take off the edge" rather than full on suspension support.

Pictures below are spacers removed, and truck is sitting level with jack removed.

View attachment 67628


View attachment 67627

I would have thought the gap would be larger. Leaning more towards Timbrens now. Thanks for the pics

 

[silver billet]

Thought about it overnight. For what I'm trying to accomplish, I think Timbrens are the wrong direction. They are definitely shorter than the Sumo's, so unloaded they would definitely perform better. But loaded, they must perform worse. You can't have a short progressive shock that is effective, and then be more comfortable (less jarring) then a longer progressive shock while it is in operation. The length of the spring allows the Sumo to work over more distance, thereby making it more progressive and less jarring during it's length of operation.

I pull several different trailers, from a light fishing boat to a heavyier ski boat to a utility trailer to a 4000 pound RV (the boats aren't mine but I pull them occasionally). Concievably, one of those trailers would give just enough tongue weight so that air gap from timbrens is pretty much gone, and then every time you hit a bump the timbren would connect and make the ride actually rougher. A youtube video I watched confirms that the TImbrens are more jarring.

I'm going to leave these in for my trip next week and see how they work when pulling my RV. But I think I'm going to return them for the lighter pair (blue shocks), and if that doesn't clear up the unloaded ride then I will just "do it properly" and switch to air. For double the price of these Sumo's I could get air installed, and over the course of 5 years or length of time I keep the truck, it would be worth it to get a nice unloaded ride back.

 

[Futureboy61]

I haven't seen much information on this forum regarding these helper springs. I have a trailer + WDH that is sitting level, but the stock shocks feel to bouncy while driving, and the bounce is what I'm trying to reduce, not trying to carry more than my payload.

So I purchased the sumo springs, the medium/black ones rated at 1500 pounds:
SSR-307-47

Installation is straightforward to understand. Jack/block up the truck a few inches using the hitch, keep the rear wheels on the ground, chock off the front so it doesn't roll. Then crawl underneath and pull out the factory bump stops with your hands, and then put Sumo springs in their place. Lower truck, and the springs will touch the axel when jack is removed.

Which brings me to the problem I have; they have COMPLETELY transformed my unloaded ride quality, and in a very bad way. I feel like I'm driving a 3500 now, my head is bopping up and down and back is jerking around. Have not yet connected my RV (4000 pounds), but very unhappy with them at this point. All the information I read was that they were supposed to be unnoticeable when truck is unloaded, so factory shock feeling. This is not true at all. I could feel the difference instantly, even just driving down my gravel driveway and going through the pot holes in first gear.

The springs do come with a spacer that can be removed. I may try that, the spacer is about 1 inch or so, my concern is that with a load on the back, there may be an air gap still until you hit a bump, and then at that point when the sumo springs touch the axle there might be a very noticable "hit".

Perhaps I ordered the wrong model. I might need the blue ones. Next week I tow my trailer 4 hours, so I will have another update at that point.

Silver bullet, I did the same thing and had the same experience. I went back in and removed the 1 inch spacers that I also put on the first time like you. That brought my UNLOADED ride back to the OEM smoothness. The SUMO SPRINGS now only engage when I hit a significant bump on the road or under load. I pulled my 9200lbs. trailer and it rides very well with the SUMO SPRINGS. I'm a fan.

 

[silver billet]

Silver bullet, I did the same thing and had the same experience. I went back in and removed the 1 inch spacers that I also put on the first time like you. That brought my UNLOADED ride back to the OEM smoothness. The SUMO SPRINGS now only engage when I hit a significant bump on the road or under load. I pulled my 9200lbs. trailer and it rides very well with the SUMO SPRINGS. I'm a fan.

That's good to hear, what color did you get? Blue (lightest), Black or Yellow (stiffest)?

 

[LoNeStAr]

I have been going back and forth between wanting Sumo’s or Timbrens. I have talked to people at Sumo, Timbre, etrailer and others to get their point of view. Timbrens definitely have a larger following, they have been around longer, and are made of a more dense material.

If I go Sumo I will go with the black set and if I go Timbren I will go with the double convoluted pair, allow for a bit of a softer ride. I want a 1” gap from the bottom of the helper spring and my axle because if it squats an inch before hitting the axle the squat will make my truck level since I have the stock rake.

Air bags is not an option for me because I have no interest in the maintenance or spending the time airing them up. I am just looking for an install and forget it.

Let us know how your tow goes

 

[LoNeStAr]

Do you guys know if the weight capacity for the sumo’s is rated per spring or together as a pair? So, the black one’s you got are rated at 1500 lbs total or per spring?

 

[silver billet]

I don't know how their weighted. I did call them up and they said it wouldn't damage them if they are fully compressed, they rebound etc.

So I towed with my truck 4.5 hours, and it was also very windy today. RV's in front of me were going 80 km/h in a 100 km/h zone and I saw more than 1 zig zagging all over the place.

Initially I had to turn around after 3 km, absolutely brutal and I knew I wouldn't make it 5 hours like that. Started adjusting my WDH, took several test trips, but then it settled right down and I'm very happy with the performance of the springs. My trailer is about 4000 pounds, truck still had a very slight rake to it after getting WDH dialed in. It felt very planted, going over bumps and dips in the road, just 1 little "sink" and then the truck was instantly settled after that. There was no jarring hits, just a very firm suspension, like "1 bounce per bump" type of deal, none of this constant bouncing, like there is a really big fat guy bouncing up and down on the end of the bumper.

How much of that was due to tweaking the WDH? I do know that had far more effect than the sumo springs, it went from "suicide by wind" to "one hand on the wheel" just by dialing in the WDH. Part of the problem was sway, part of it was multiple bounces per bump. The springs are supposed to help with sway as well. But I do know this is the best I've felt pulling this trailer with my truck. I have also got the hellwig swaybar set to the tightest setting.

I think it could still be improved yet, my next mod will be 20 inch rims and better tires. Can't prove it, but I suspect my current factory 18's are a little squishy.

 

[APEracing]

I had a similar experience with the black Sumo springs. You absolutely have to remove the 1" spacer or ride quality will be horrendous unloaded. I called Sumo directly and tech support noted these can be "tuned" by cutting into the insert (you wont damage its integrity) at a diagonal so you would remove about 1" in the front and taper it down towards the back. This will make initial loading of the spring a softer effective rate, then after its fully loaded you get the full benefit of the spring support. I did this and VERY happy with the end result. I'm towing a ~6,000lb car trailer.

 

[LoNeStAr]

I don't know how their weighted. I did call them up and they said it wouldn't damage them if they are fully compressed, they rebound etc.

So I towed with my truck 4.5 hours, and it was also very windy today. RV's in front of me were going 80 km/h in a 100 km/h zone and I saw more than 1 zig zagging all over the place.

Initially I had to turn around after 3 km, absolutely brutal and I knew I wouldn't make it 5 hours like that. Started adjusting my WDH, took several test trips, but then it settled right down and I'm very happy with the performance of the springs. My trailer is about 4000 pounds, truck still had a very slight rake to it after getting WDH dialed in. It felt very planted, going over bumps and dips in the road, just 1 little "sink" and then the truck was instantly settled after that. There was no jarring hits, just a very firm suspension, like "1 bounce per bump" type of deal, none of this constant bouncing, like there is a really big fat guy bouncing up and down on the end of the bumper.

How much of that was due to tweaking the WDH? I do know that had far more effect than the sumo springs, it went from "suicide by wind" to "one hand on the wheel" just by dialing in the WDH. Part of the problem was sway, part of it was multiple bounces per bump. The springs are supposed to help with sway as well. But I do know this is the best I've felt pulling this trailer with my truck. I have also got the hellwig swaybar set to the tightest setting.

I think it could still be improved yet, my next mod will be 20 inch rims and better tires. Can't prove it, but I suspect my current factory 18's are a little squishy.

Do you feel like the sumo’s helped remove any of the sway?

 

[LoNeStAr]

I had a similar experience with the black Sumo springs. You absolutely have to remove the 1" spacer or ride quality will be horrendous unloaded. I called Sumo directly and tech support noted these can be "tuned" by cutting into the insert (you wont damage its integrity) at a diagonal so you would remove about 1" in the front and taper it down towards the back. This will make initial loading of the spring a softer effective rate, then after its fully loaded you get the full benefit of the spring support. I did this and VERY happy with the end result. I'm towing a ~6,000lb car trailer.

Can you take pics of how you cut yours?