Which shocks stop the body roll?

[hotjag1]

My current motorhome is on a Freightliner chassis. Probably original shocks with 43,000 miles.

The ride is good, but going in and out of uneven driveways, the coach rocks from side to side, and leans more than "I think it should" around curves.
I have read many posts comparing Konis and Bilsteins. Most of the comments are in regard to which shock doesn't have a harsh ride over freeway expansion joints and provides the smoothest ride overall.

I don't really care how smooth the shocks are over expansion joints. I just want to get rid of the side to side rocking coming out of driveways at an angle, and excess leaning going around curves.

So, for my particular question, which is better. Konis, or Bilsteins?

[wolfe10]

Sorry, we are talking about Class A coaches.

And the earlier post is absolutely correct. Were you to get a shock capable of controlling sway (side to side motion) it would be WAY too stiff for normal driving.

Shocks should control porpoising. Sway bars should control sway. Yes, 8 outboard air bag suspensions are less susceptible to sway than those with 4 bags mounted inboard. But with the addition of the proper sway bar, sway can be managed on all of them.

[kevden]

rgatijnet1 wrote:
No shock will stop the body roll. That is not what they are designed to do. A good shock will slow down the roll and minimize the continuous rocking that the coach would have without the dampening effect of the shocks.
To stop the roll, your springs would have to be so stiff that your ride would suffer in all other conditions.
The shock is NOT a spring. It is a dampening fixture to slow down spring movement, but not restrict it.

I am not sure if they still make them, or if they would even have one for a motorhome, but I put 4 edelbrock IAS shocks on my 1997 ford f150 and my 2000 chevy astro van and the difference from stock was amazing. They are designed to stop body roll when cornering, but ride smooth over bumps.

[JimM68]

Our 8 outboard bag roadmaster chassis is not susceptible to rocking, but still, I enter driveways very very slowly. Perhaps slowing down is all you need to do?

Our rig has height valves on both sides of the rear axle. The air to the right and left air bags is separately controlled, by the computer, for the express purpose of maintaining the correct height (independently) on each side. When the coach rocks, the system fights it. It doesn't completely overcome all that weight, but it tries.

I'd always thought such a system was standard on all DP's?
These "motion control valves" would have no effect... air pressure cannot flow freely left to right in a Monaco...

As was said, shocks dampen the movement of the springs. They slow the reaction speed. Usually, shocks are valved so they heavily resist compression, but do not resist extension. this lets the springs work, and dampens the tendency to porpoise.

While I like my sportscars to react "Taughtly" my DP makes me happier when it is smooth and soft. As long as it isn't bouncy and doesn't porpoise up and down.

Driveways, and sudden bumps hit at an angle, those are best done slowly.

[hotjag1]

After reading the past several replies, I'm not sure if I need heavier sway bars or motion control valves.

It rides and handles good going down the highway and passing trucks and wind have almost no effect on it. I can easily drive it with one hand(if I wanted to).

It is only the side to side rocking coming out of driveways that I don't like.

et2 replied that Konis considerably reduced his back and forth rocking, so now I'm not sure.

The motion control valves sound like they may control the motion that I am referring to though, and I was not aware of that product...Thanks.

[jtfcons]

smlranger wrote:
I installed the Super Steer Motion Control valves on my Freightliner XC chassis when I had my previous motorhome. The difference in handling was significant, much less roll, less of the wobble when going over driveways. Best thing I put on that chassis to improve handling.

I too am a fan of the Motion Control devices. They will not do much for the speed bump roll or a driveway bump, but provide significant improvement to body roll and handling on the road, passing trucks, etc. Best handling improvement for my Spartan Mountain Master chassis, which has large sway bars (1-1/4 to 1-1/2 inch diameter) and a solid front axle.

[et2]

I posted last week about my switching to Koni shocks from the original shocks (Sachs). We have a 2013 Fleetwood Expedition 42' DP with around 2500 miles. They made a very noticeable difference on how our coach handles the side to side motion. As a matter of fact, that was the most notable difference to me. The ride is smoother as well.

So from my experience there is a benefit to getting a improved or new shock. Being that the ones that were originally on it were fairly new, you'd think a new shock wouldn't be noticeable. It was immediate. When exiting a drive that side to side is now minimal and the blinds slapping back and forth was much less.

Not saying you don't have sway bar issues, but if needing new shocks, I would recommend Koni as a option for you.

[zman-az]

Might want to take it to Freightliner, explain your problem and have them weigh the 4 corners, make adjustments and get a front end alignment. It could be as simple as something not in alignment or other issues which they should be able to find during the alignment process.

[J-Rooster]

rgatijnet1 wrote:
No shock will stop the body roll. That is not what they are designed to do. A good shock will slow down the roll and minimize the continuous rocking that the coach would have without the dampening effect of the shocks.
To stop the roll, your springs would have to be so stiff that your ride would suffer in all other conditions.
The shock is NOT a spring. It is a dampening fixture to slow down spring movement, but not restrict it.

X-2, Shocks are very good at stopping porpoising!

[down_home]

The Super Seer Motion Control Valves may e the same thing as this. They fit in the air line between the left and right air bags front and rear. They stop the air from rushing from the high side to the low side air bag on corners, trucks passing etc. They restrict the air flow. I had a Person that worked for one of the Shock Mfgs tell me tht was a better solution than larger sway bars. Seems Freightliner made some lighter chassis for Fleetwood and others a few years. The larger bars weren't the best solution as they worked the chassis too much.

[mci7]

Do not understand the issue about body roll. My Foretravel simply uses 8 air bags mounted outside the tires, no sway bars, just 8 shocks and can not make it lean nor roll.
My old MCI conversion used inboard air bags, would lean & roll a little but from drivers seat there was no noticable discomfort at all.
Dave M

[hotjag1]

Thanks again for the information and enlightening me regarding sway bars and motion control units. I will check into these products instead of wasting money on different shocks.

[smlranger]

I installed the Super Steer Motion Control valves on my Freightliner XC chassis when I had my previous motorhome. The difference in handling was significant, much less roll, less of the wobble when going over driveways. Best thing I put on that chassis to improve handling.

[southpark]

It may pay to look at the airbag placement of various chassis designs. Freightliner's are large bags close to the center. A soft ride, but not much to keep from leaning.

At the opposite end you have some chassis makers who use smaller bags, and/or place the bags on the outer edge of the chassis. Some of these even come with active air systems which will quickly adjust the amount of air in the various bags to limit lean to the side in turns and aggressive handling.

There are actually differing opinions, however, on what people prefer. Different strokes for different folks, as they say. It sounds like, however, that if you ever switch your coach you may want to explore some of the other designs out there.

Finally, I'm not saying sway arms or Super Steer Motion Control units won't help -- nor am I saying they will (but some people are big fans and they are relatively cheap in the scheme of things RV). Just pointing out the differences in design philosophy which may frustrate your efforts to get exactly the ride you're after.

Good luck with everything.

[JimM68]

There are a lot of differences in chassis design.
Our 8 outboard airbag roadmaster chassis doesn't even have or need antisway bars...
Spartan is also highly regarded, with or without independant front suspension.
The trailing arm freightliner chassis need a lot of help to prevent sway.