Sumo Springs - rear or front & rear? - Page 2

jtham · 10-16-2018, 06:55 AM

I posted in June 2017 that I had installed sumos on my sprinter RV and like them.
After one year I can report that I have removed them. The ride was too harsh for us. We would feel every bump. The suspension rode on the sumos not allowing the springs or shocks to come into play. I have a larger sway bar, Koni’s all the way around and new Michelin tires. We will get a little more sway now, but a more pleasant ride. It’s just our view on this. I know others have different opinions.
By the way, I would sell them cheap if anyone wants them.

BobC · 11-09-2018, 12:13 PM

Is it just me or is it hard to get a read on Sumo Springs? Some say it made their ride harsh, others say it improved it.

rvbud · 11-10-2018, 05:35 AM

I note that jtham has a 24' View, quite a different chassis than W20 or F-53. My comments are above. Adding Sumo Maxims would be the first suspension mod I make if I ever by another Class A with F-53. Period. Call Sumo in California, they will be happy to give you advice on the proper model no. Took me about 4 hours to install.

ranchdog · 11-10-2018, 07:14 AM

We have a 2015 Vista LX 27N on an F53 chassis and we put Sumo Springs front and rear along with a Roadmaster steering stabilizer. We think they are all a great improvement. They have greatly reduced the swaying and porpoising. In some places the bumps are a little harsh but the rest of it is more than worth it. We never expected it to ride like the 40' DP that we downsized from. It rides more like our F-350 dually and as far as I am concerned it is a joy to drive. It has great acceleration and rides firmly on the road. We've been doing this for more than 35 years and think this coach is the best we've ever had.

RvExplorer · 12-17-2018, 05:06 PM

I was just about to purchase an extended warranty for my 2018 35f and I noticed in the fine print that any suspension modification could void any part of the coach affected by the suspension (where does that end...?). I called the company (Wholesale Warranties....good company $3,845 for 7 year 70,000) and they confirmed that Sumosprings would void anything related to the suspension, shocks, diff, breaks and so on). So, I now have to decide which is more important. I have the Sumos but have not installed them yet. I am leaning toward no Sumos and having the warranty.

So far I have doneothing to enhance the ride. I have put about 2000 miles on it. I need to try tire pressure. I have been in one severe wind storm and it required my full attention when a truck passed but otherwise I don't see a problem. I definitely do not want a stiffer or firmer ride.

Interested in any feedback.

BobC · 12-17-2018, 07:48 PM

Quote:

Originally Posted by RvExplorer

I was just about to purchase an extended warranty for my 2018 35f and I noticed in the fine print that any suspension modification could void any part of the coach affected by the suspension (where does that end...?). I called the company (Wholesale Warranties....good company $3,845 for 7 year 70,000) and they confirmed that Sumosprings would void anything related to the suspension, shocks, diff, breaks and so on). So, I now have to decide which is more important. I have the Sumos but have not installed them yet. I am leaning toward no Sumos and having the warranty.

So far I have doneothing to enhance the ride. I have put about 2000 miles on it. I need to try tire pressure. I have been in one severe wind storm and it required my full attention when a truck passed but otherwise I don't see a problem. I definitely do not want a stiffer or firmer ride.

Interested in any feedback.

I wouldn't jeopardize an extended warranty for a suspension mod that may or may not materially improve my ride. I think that if you weigh your MH (preferably 4-corner weights) and inflate your tires to the table-specified PSIs +10%, you will see an improvement, particularly if you're currently inflated to the pressures specified on the "door plate". As you put on more miles, you'll become more skilled in terms of speed, anticipation, etc., all of which will improve your driving experience.

rvbud · 12-18-2018, 06:39 PM

Void the warranty on the entire motorhome, or just suspension related issues? I ‘m not aware of too many warranty issues with steering, springs or shocks on the F53. Many people revise the chassis with better shocks, bigger sway bars, addition of track bar in rear for safety...I’m all for improved safety and would fight like hell if the mfg declined warranty work for non-related issues. I’ve added (on my ‘08 F-53) Sumos, changed shocks to Koni FSD’s, added larger sway bar in front and additional swaybar with with a track bar in rear...and would do it all over again.

John Locke · 12-19-2018, 11:48 AM

I'm looking at installing Sumo Springs myself. When talking to the manufacturer they pointed out it's important to buy the model that's rated for your particular vehicle weight. If you buy the wrong spring it could result in a stiff ride. I've used air bags in the past and that's another option I'm considering for the front, where the cab ride is more sensitive to spring rate.

Roadmaster sways bars are definitely on the list of upgrades coming to my rig, along with rear track bar.

BobC · 12-19-2018, 03:41 PM

I'm sure you could at least upgrade your shocks without affecting your warranty but you's still want to check first.

PatL · 10-20-2019, 06:36 AM

How do they affect the ride?

RvExplorer · 10-20-2019, 08:44 AM

You need to research on YouTube “springs in parallel bs spring in series”.

It’s a law of physics that spring in parallel as with sumos will stiffen the ride. Which does refuse sway

My extended service contract could link may thing beyond suspension to the staffer ride. The refrigerator (residential) comes to my mind

I sent the springs back in favor of the warranty

JMHO

John Locke · 10-20-2019, 03:47 PM

Instead of the Sumo's, I elected to go with Roadmaster heavy duty sway bars, front and rear. I will try those for a few thousand miles and see how I like them. So far they seem great to mitigate the leaning and waffling left and right as trucks go by, or when I pass big trucks pushing a lot of air. I haven't experienced high winds yet, but I expect the new sway bars to be a good improvement with that too.

My 1999 Pace Arrow with V10 Ford F53 weighed about 1200lbs less than my Vista 32YE, even though both rigs were the same length. I believe the difference is mainly due to the Pace Arrow having no slides, and the 32YE does. Part of that extra weight for the slides is up high, making the 32YE more top heavy IMO. The suspension between the 1999 and 2018 appears the same, with the same GVW rating of 22,000lbs. Given the added weight, I believe this is why my newer 32YE doesn't handle as sweet as my 1999. I'm hoping the sway bars mitigate this enough to feel more like my 1999.

**creativepart** · 10-20-2019, 04:52 PM

We have Sumo Springs front and rear. When we first got them I thought they helped with tilt/sway quite a lot. But after about 15,000 miles of use I think they make the ride too harsh.

I plan to remove the front Sumo's only and see if I can get a bit softer ride along with the reduction in tilt/sway from the remaining rears.

TeeJay - kind of a handling expert on IRV2.com - has removed his Sumo Springs and replaced them with air bags. He likes the improvement. I'm not sure I want to do more. But it won't cost much to remove the front Sumos.

Currently, I have a Roadmaster RSS Steering Stabilizer, Koni FSD shocks and a Roadmaster Rear Anti-Roll bar... along with the Sumo Springs.

Rough roads, and there are far too many of those, are making trips unpleasant too much of the time.

**macnut** · 10-20-2019, 10:25 PM

I also had sumos front and rear. In my case, I removed the rear ones because, since they are one-piece, they reduced the rear play too much making for a harsher ride. The front ones have separate pieces for the top and bottom so I left them on. The ride improved, though still not as good as I would like.

I also have koni’s and they have smoothed the smaller bumps and cracks on the road, and eliminated the porpoising (up down up down) over larger bumps. It now goes down and then up only once. However, you still feel the large bumps and cracks. I think the only thing left for me now that I have front and rear sway bars, front and rear track bars, 8 koni’s, sumos on rear, and a stabilizer bar up front....is to go with Liquid Springs, but I don’t want to spend that much on a smoother ride. I think I can live with what I have now fine.

**macnut** · 10-20-2019, 10:32 PM

Quote:

Originally Posted by mjplumber

Has anyone tried super steers koni quad shock install on their Winnebago?

I had mine installed at Henderson’s in Grants Pass Oregon. It has made an improvement in small bumps and cracks, and also eliminated porpoising. Worth the cost? I think so, but time will tell.

John Locke · 11-23-2019, 07:53 PM

Quote:

Originally Posted by macnut

I think the only thing left for me now that I have front and rear sway bars, front and rear track bars....

I highly recommend Roadmaster sway bars, front and rear. They aren't cheap, but when I put them on my 32YE Vista, it turned into a different RV. Excellent handling now. It's go-kart like in the turns, and doesn't get blown around at all hardly. The unexpected benefit is the RV tracks as straight as an arrow now. I haven't changed the stock shocks, they seem to work fine for now.