Super Steer

[Roadtrek Adventuous RS1]

Originally Posted by Boxster1971

Agreed - I'd like to see a photo of a track bar installation on the rear axle of a 3500 Sprinter. Id like to understand what problem the track bar is going to solve.

Again, this is the explanation... let me know if you think this is incorrect...

Track Bars help with results from tail wag from wind and passing trucks that disturb straight line driving.

And,

Sway bars are neutral when going straight and are only effective in turning but may give a slight firm feeling in the suspension.

I have definitely noticed a difference in turning corners....and for me the Koni FSD shocks made a significant difference...

Again, your results may vary....

I DID NOT want to spend $10,000 on an air suspension....

How many of you are willing to invest $10 grand on a very complicated system like that...
Improved ride..for ten grand.?

It's an enormous amount of money....No thanks.

[booster]

Would agree with most of it, except swaybars are not necessarily neutral when going straight. If there is wind from the side trying to tilt van, especially in gusts, the swaybar is what keeps the van from leaning and swaying, which can cause rear steering from the live axle, which need steering corrections from the driver. Swaybars don't change the stiffness of the suspension in things like dips where both rear wheels it it at the same time, but they will stiffen up the bumps on one wheel bumps because the swaybar rate adds on to the spring rate for the bump side.



The description of what a track bar does is the normal one, but I have never heard of "tail wagging" being an issue in Sprinters or other class b's. It is always sway that we hear about.

[Boxster1971]

Originally Posted by oilman

I believe this is a picture or the trac bar on a sprinter.

https://supersteerparts.com/blog/ss7...inter-chassis/

Thanks - good info. That photo is a Sprinter Cab-Chassis used for C-class builds. They have stronger frame rails than the Semi-unibody Sprinter vans.

I doubt that installation does anything to center that rear axle as claimed. Those sway bar frame brackets are designed to resist vertical movement and only have minimal lateral strength compare to the leaf springs and their beefy mounting points.

[Roadtrek Adventuous RS1]

Originally Posted by booster

Would agree with most of it, except swaybars are not necessarily neutral when going straight. If there is wind from the side trying to tilt van, especially in gusts, the swaybar is what keeps the van from leaning and swaying, which can cause rear steering from the live axle, which need steering corrections from the driver. Swaybars don't change the stiffness of the suspension in things like dips where both rear wheels it it at the same time, but they will stiffen up the bumps on one wheel bumps because the swaybar rate adds on to the spring rate for the bump side.


The description of what a track bar does is the normal one, but I have never heard of "tail wagging" being an issue in Sprinters or other class b's. It is always sway that we hear about.

I was getting a significant amount of tail wagging passing larger big rigs on the open road and high winds.... I experienced this on a cross country trip last fall...

You may not necessarily find this in just driving shorter distances...

The sway bar is for side to side movement and cornering..

My old shocks were worn out..I saw the old parts...firmer more controlled ride....

Incidentally, I noticed that "no one " on this forum said anything about "air suspension" removing all "bouncing" at the rear seat of the Sprinter...and road conditions vary depending on location..

Maybe that's just not possible with the dynamics of this vehicle?? There's a lot of weight behind the rear axle.... Someone told me that even with an air suspension... there's going to be some vibrations back there....

[booster]

How do you know it was tail wagging and not sway? They are very hard to tell the difference in the cab when going straight down the road. The trucks pushing a B around are the classic signs of sway, or rocking of the van. not of straight horizontal motion of axle movement. The sway can cause rear steer and if the van has understeer anyway, like just about every duallie and most heavy tail Bs do, you have to make a fairly large correction. The sway bar reduces the sway, so reduces the rear steerinng, and at the same time it reduces understeer which makes the front react better to steering wheel inputs. That all makes for easier driving because of smaller steering wheel inputs. Swaybars do not directly help axle movement as they only work in the vertical direction.


The normal thing you will get if you have relatively bad understeer is that a truck coming up in the lane next to you from behind will push you away from it as it approaches, so if the van is on the left of you the push will be to the right. Once the truck gets past you the van will get pulled into the direction of the truck so it will move to the left. The feeling of getting pushed away and then pulled back into the other lane can be very scary for some folks if it is excessive. Big sway bars on the rear, and proper tire pressures can reduce the issue a lot in most vans.

[Roadtrek Adventuous RS1]

Originally Posted by booster

How do you know it was tail wagging and not sway? They are very hard to tell the difference in the cab when going straight down the road. The trucks pushing a B around are the classic signs of sway, or rocking of the van. not of straight horizontal motion of axle movement. The sway can cause rear steer and if the van has understeer anyway, like just about every duallie and most heavy tail Bs do, you have to make a fairly large correction. The sway bar reduces the sway, so reduces the rear steerinng, and at the same time it reduces understeer which makes the front react better to steering wheel inputs. That all makes for easier driving because of smaller steering wheel inputs. Swaybars do not directly help axle movement as they only work in the vertical direction.


The normal thing you will get if you have relatively bad understeer is that a truck coming up in the lane next to you from behind will push you away from it as it approaches, so if the van is on the left of you the push will be to the right. Once the truck gets past you the van will get pulled into the direction of the truck so it will move to the left. The feeling of getting pushed away and then pulled back into the other lane can be very scary for some folks if it is excessive. Big sway bars on the rear, and proper tire pressures can reduce the issue a lot in most vans.

Booster..ok, that's a good question...I'll try and explain this to you....

During the 11,000 miles trip all over the USA last fall..we were in many situations where larger big rigs were passing me on the left side and getting in front of me and slowing back down.... annoying cat and mouse situation ... "Whenever I was behind them after they passed me..I was getting sucked into the downdraft of the wind they were pulling behind their big rig...and I noticed that the rear of my Sprinter started to vibrate a little more....i wasn't sure at first.. but noticed that this happened every time we got behind a big rig..the front end of the Sprinter would shake and I could feel the tail wagging....

Also, on really strong cross winds..20 to 25 MPH.....we were experiencing some 25 MPH plus gusts...and the van would shudder.. causing me to do steering corrections...
The front of the van was much more stable..but, it was a little disconcerting driving all across the country with situations like this.... I would turn the wheel a little into the opposite of the wind direction to counter the gusts..

This was in addition to the fact that my shocks seemed a little softer and more like I was floating around a bit...

On cornering, I had some body leaning and going over uneven pavement or in and out of driveways...the van porpoising caused the cabinets to shake pretty violently ..a lot of noise back there..

Now, when I go over speed bumps or into driveways..it's all gone.. I would say that's a tremendous improvement....

I just got the van back yesterday and have not had a chance to test out the tail wagging, BUT, I imagine that the additional trac bar and anti-sway bar..this will be a whole lot better.... The vehicle feels way more secure, and despite what others may think...I don't care...it's my van and my responsibility ...

The comments by others who don't agree with what I did is irrelevant ... they can spend whatever they want....

I'm sure what you wrote is true...

"The normal thing you will get if you have relatively bad understeer is that a truck coming up in the lane next to you from behind will push you away from it as it approaches, so if the van is on the left of you the push will be to the right. Once the truck gets past you the van will get pulled into the direction of the truck so it will move to the left. The feeling of getting pushed away and then pulled back into the other lane can be very scary for some folks if it is excessive. Big sway bars on the rear, and proper tire pressures can reduce the issue a lot in most vans"

It is definitely scary....and something most people don't experience every day unless they are traveling on the open road...

AFTER a number of phone conversations with Super Steer and more consultation with my RV shop on solving my issue... they recommended the shocks, sway and trac bar for my Sprinter......

Total cost... just under $3,100.installation and parts....

[booster]

We all get the buffetting when directly behind a big truck, and it can be very noisy and generates vibration all through the van. It is the wind very rapidly switching back and forth in resonance around the big truck. If your van is handling well, all it should be is noise and vibration that is really very fast rocking of the van. The van should still go straight without undue steering corrections.


20-25mph winds and gusts really shouldn't be all that scary if things are right, and neither should the push-pull of a passing truck. We have single rear wheels, so it is easier to reduce understeer than it is with duals, and we have done everything we can to reduce understeer. We have come across Wyoming, Montana, Colorado, and other wide open areas in 40-50mph winds and were able to drive over 70mph through it and around trucks. If the van responds well to the steering because of no or little understeer, the inputs are much smaller and easier, so the entire driving experience gets easier. We barely feel the push-pull of passing trucks. On one trip we literally saw a nearly new class C that had the roof blown off and a fiver that had a window blow out, it was so windy 50+gusts in the valleys. The good was that we got 36mpg for about 10 miles while we going with the wind, off the Scangauge. We had a hard time finding a campground along the freeway because all the RVs and trailers had stopped early due to the wind and filled them up.


Knowing the symptoms of handling issues and addressing them properly can definitely make the driving a lot more enjoyable. I hope yours turns out well, once you get out into the good testing situations.

[Roadtrek Adventuous RS1]

Originally Posted by booster

We all get the buffetting when directly behind a big truck, and it can be very noisy and generates vibration all through the van. It is the wind very rapidly switching back and forth in resonance around the big truck. If your van is handling well, all it should be is noise and vibration that is really very fast rocking of the van. The van should still go straight without undue steering corrections.


20-25mph winds and gusts really shouldn't be all that scary if things are right, and neither should the push-pull of a passing truck. We have single rear wheels, so it is easier to reduce understeer than it is with duals, and we have done everything we can to reduce understeer. We have come across Wyoming, Montana, Colorado, and other wide open areas in 40-50mph winds and were able to drive over 70mph through it and around trucks. If the van responds well to the steering because of no or little understeer, the inputs are much smaller and easier, so the entire driving experience gets easier. We barely feel the push-pull of passing trucks. On one trip we literally saw a nearly new class C that had the roof blown off and a fiver that had a window blow out, it was so windy 50+gusts in the valleys. The good was that we got 36mpg for about 10 miles while we going with the wind, off the Scangauge. We had a hard time finding a campground along the freeway because all the RVs and trailers had stopped early due to the wind and filled them up.


Knowing the symptoms of handling issues and addressing them properly can definitely make the driving a lot more enjoyable. I hope yours turns out well, once you get out into the good testing situations.

Thanks...I appreciate your comments...

You know.. I might have been wrong about the wind speeds...even so...it was quite unsettling.. and a little stressful..

Interesting that you mentioned that single wheels were "easier to reduce understeer than with dual wheels"... don't really know why that is...do you??? I was definitely interested in getting the dual wheels for

1. Stability
2. More weight capacity..


Just seemed like a good idea...less chance of a roll over... But, everyone said you need an enchanced sway bar....

The shocks issue kind of surprised me by the low mileage.. but, it's a constant weight and Mercedes Benz probably didn't know it was going to converted to an RV..

I don't know.. I'm not sure I would drive in 40 -50 MPH winds... find a nice place to stay..
I'll know this fall when we take the rig across country again....

[booster]

Understeer really just means that the front tires have less grip than the rears do. With understeer the front is actually not getting the best traction, so you need a bigger steering input to overcome the poor traction condition when trying to keep the van going straight.



I think that the biggest contributor to understeer in duals is that you have twice as much tire and usually more rear axle weight than you have with single rear wheels. Bigger tires in the rear in single rear wheel vans will increase understeer, and so will more weight in the rear, so it makes sense. Many times the front tires are also smaller than they are on the single rear wheel vans so that will also increase understeer. When starting with those disadvantages, it is harder to reduce the understeer as to as low a level. MB figured this out and started putting wind assist on the van to combat the situation, and by all accounts it seems to work pretty well.


The duals will probably be trying to move the van in a straight line, but will also resist a steering input when the wind or road push it offline.



Every van comes from the factory setup so that they will not oversteer when empty. Oversteer is when the rear wheels have less traction than the front, and is defined well by the term "swapping ends" or spinning out. Oversteer is much more dangerous than understeer, so they setup to never oversteer on normal surfaces. Once you load up the van, it understeers even more, and you get the issues that class b vans have. Since the weight is always in the van, you don't have to worry about oversteering when empty and can work to reduce the understeer. It is highly unlikely that you could ever get a class b to oversteer on pavement, so also not likely you would ever get a hazard with the changes.

[BBQ]

Originally Posted by Roadtrek Adventuous RS1

Thanks...I appreciate your comments...

You know.. I might have been wrong about the wind speeds...even so...it was quite unsettling.. and a little stressful..

....

Look at the big picture... you have over 8,000 lbs sitting on dual wheels. You RV is not going anywhere except the direction you pointed your steering wheel.

The drum effect can amplify any road noise and wind noise to artificial frightening levels. It's not just the RV; any van will have that effect.

[Roadtrek Adventuous RS1]

Originally Posted by BBQ

Look at the big picture... you have over 8,000 lbs sitting on dual wheels. You RV is not going anywhere except the direction you pointed your steering wheel.

The drum effect can amplify any road noise and wind noise to artificial frightening levels. It's not just the RV; any van will have that effect.

Sorry, could you please explain what you mean by this...

Thanks...

The drum effect can amplify any road noise and wind noise to artificial frightening levels. It's not just the RV; any van will have that effect.[/QUOTE]

[Mat Mobile]

To the OP, not sure why you are offended by some of the comments. You did ask a very open ended question: "Have any of you considered making upgrades like this or are you sticking with the original equipment?"

For each issue, there are different levels of improvements that can be made. From replacing worn out components ($) to installing a whole new suspension system ($$$). Depending on your needs, you can figure out what suits you.

The ones you made will definately help you out. The trac bar should definately help you out for passing and following big rigs. It basically removes the play in the rear suspension that is emphasized by the wind pushing at the top of your vehicle (by cross winds and the vortex caused by big rigs). The large flat surfaces on each side of these vehicle almost acts like "sails" and can put a lot of force to the sides of the vehicle. It's made even worse by the fact that the top of the vehicle can act as "leverage" to the winds. Not sure if my explanation is comprehensible.

The only thing all these modifications don't address is this issue: "and traveling over any uneven surfaces makes the cabinets in the rear shake like an earthquake. Not to mention any passengers who sits in the rear bench seat...they bob up and down...." from your original post.

That can only be corrected by the the spring rate. That's the main reason why the air spring upgrade is mentionned.

I have a completely different vehicle (Roadtrek Versatile 200 on a Chevy van) that had the exact same issue. It aggravated me enough that I was happy to replace the spring pack with a new set of leaf springs calibrated for the weight of the vehicle (more thinner leaves). It was about 1,300$ + maybe 2 hours labor. Of course, there's more to it than just that (you need to read the thread in my signature), but that's what I did to address that issue.

A lot of the members on this forum join right after they purchased their RV and have already committed to upgrades suggested by local shops. But this forum has lots of very knowledgeable and experienced members who have tried various upgrades with varying results. I found that a lot of the upgrades I have made have been tweaked by information I have found on this forum. Keeping an open mind goes a long way.

That being said, I'm doing things my way, even if they are a little over the top for most members here! But hey, "breakthroughs" only happen by pushing the envelop from time to time.

[BBQ]

Originally Posted by Mat Mobile

To the OP, not sure why you are offended by some of the comments. You did ask a very open ended question: "Have any of you considered making upgrades like this or are you sticking with the original equipment?"

....

That's correct.

This is the internet, you get all kinds of answers.
(good, bad, good natured but wrong, stupid, ignorant, trolls, good answer but wrong application, too much detail, not enough detail, jokes, sly remarks, offensive, belittling, condescending, not condescending but words appear that way on internet, OT to politics/religion... as you can see there are more negative descriptions than good ones. )

As always, you take what you like and ignore/discard what you don't like.
You have no obligation to respond to all the replies.
Life is good.

[BBQ]

Originally Posted by Roadtrek Adventuous RS1

Sorry, could you please explain what you mean by this...

Thanks...

The drum effect can amplify any road noise and wind noise to artificial frightening levels. It's not just the RV; any van will have that effect.

[/QUOTE]

The hollow cavity inside the RV/van will create a drum effect, making many sounds more dramatic than they really are.

[Roadtrek Adventuous RS1]

Originally Posted by BBQ

That's correct.

This is the internet, you get all kinds of answers.
(good, bad, good natured but wrong, stupid, ignorant, trolls, good answer but wrong application, too much detail, not enough detail, jokes, sly remarks, offensive, belittling, condescending, not condescending but words appear that way on internet, OT to politics/religion... as you can see there are more negative descriptions than good ones. )

As always, you take what you like and ignore/discard what you don't like.
You have no obligation to respond to all the replies.
All is good.

Thanks... yes, I know other people have very different opinions...

Did you see my question about this... what did you mean when you said.....



The drum effect can amplify any road noise and wind noise to artificial frightening levels. It's not just the RV; any van will have that effect

[Roadtrek Adventuous RS1]

Originally Posted by Mat Mobile

To the OP, not sure why you are offended by some of the comments. You did ask a very open ended question: "Have any of you considered making upgrades like this or are you sticking with the original equipment?"

For each issue, there are different levels of improvements that can be made. From replacing worn out components ($) to installing a whole new suspension system ($$$). Depending on your needs, you can figure out what suits you.

The ones you made will definately help you out. The trac bar should definately help you out for passing and following big rigs. It basically removes the play in the rear suspension that is emphasized by the wind pushing at the top of your vehicle (by cross winds and the vortex caused by big rigs). The large flat surfaces on each side of these vehicle almost acts like "sails" and can put a lot of force to the sides of the vehicle. It's made even worse by the fact that the top of the vehicle can act as "leverage" to the winds. Not sure if my explanation is comprehensible.

The only thing all these modifications don't address is this issue: "and traveling over any uneven surfaces makes the cabinets in the rear shake like an earthquake. Not to mention any passengers who sits in the rear bench seat...they bob up and down...." from your original post.

That can only be corrected by the the spring rate. That's the main reason why the air spring upgrade is mentionned.

I have a completely different vehicle (Roadtrek Versatile 200 on a Chevy van) that had the exact same issue. It aggravated me enough that I was happy to replace the spring pack with a new set of leaf springs calibrated for the weight of the vehicle (more thinner leaves). It was about 1,300$ + maybe 2 hours labor. Of course, there's more to it than just that (you need to read the thread in my signature), but that's what I did to address that issue.

A lot of the members on this forum join right after they purchased their RV and have already committed to upgrades suggested by local shops. But this forum has lots of very knowledgeable and experienced members who have tried various upgrades with varying results. I found that a lot of the upgrades I have made have been tweaked by information I have found on this forum. Keeping an open mind goes a long way.

That being said, I'm doing things my way, even if they are a little over the top for most members here! But hey, "breakthroughs" only happen by pushing the envelop from time to time.

Thanks for this explanation.... with the big rigs...I would say it's fairly accurate..


The ones you made will definately help you out. The trac bar should definately help you out for passing and following big rigs. It basically removes the play in the rear suspension that is emphasized by the wind pushing at the top of your vehicle (by cross winds and the vortex caused by big rigs). The large flat surfaces on each side of these vehicle almost acts like "sails" and can put a lot of force to the sides of the vehicle. It's made even worse by the fact that the top of the vehicle can act as "leverage" to the winds. Not sure if my explanation is comprehensible.

AS for the cabinets... shaking...it's much less.....I used to get this over any bumps.. driveways, etc... that's ALL gone. The vehicle is much more controlled..

People bobbing in the rear seat... they do to a certain extent... but. I generally don't have passengers back there... AND, I don't think or have any confirmation that it would be "totally eliminated" even if I had spent the money on air suspension...

In fact..the people who did the work for me said.. NO... there still would be some vibrations back there ..it's just unavoidable with the way the van is designed.

I think I'm done with tweaking this for a while....

[Mat Mobile]

Originally Posted by Roadtrek Adventuous RS1

I think I'm done with tweaking this for a while....

Agreed. You don't have to do it all at once. And you will most likely be satisfied for a long time.

Actually, it's cool that you posted about the Trac Bar. I think it made a lot of people learn something new. Mself included so thanks!

Don't forget to post back later on with a more in depth review.

[Roadtrek Adventuous RS1]

The hollow cavity inside the RV/van will create a drum effect, making many sounds more dramatic than they really are.[/QUOTE]

OK.. thanks...yes, it is cavernous...I guess that's what my sound system is for to mask out...

[booster]

Re the track bar. I did a little reading and very similar discussions are happening in quite a few places, with no real life application testing that I saw yet.


One place mentioned something that is very true for track arm of this type, and that is the fact that is should be as long as possible to reduce the arc it travels in. The shorter the bar is the more lateral movement it causes during up and down motion from bumps, thus creating the problem it is supposed to be fixing. From the pic we saw earlier, it appears the bar of discussion is quite short.


It would be a very interesting test to see how much the axle moves laterally when the van is jacked up with axle hanging loose. I have done that test on my big old Buick Roadmaster wagon that uses coil springs, trailing arms, and a track bar. The rear axle in it moves about 3/8", so substantial.


I also think that the benefit from the track bar may turn out to be very dependent on the spring shape and location for individual vans. The closer the centerline of the axle is to the line between the leaf spring mounts, the less able the axle will able to exert the force needed to move over. The springs are not going to bend sideways, and neither will the front eye, so only the shackle might be moving over a bit. If the van has very high arch springs, or a block lift, on it, the axle centerline could be considerably below the line between the spring mounts. The leverage will put a big twisting force on the rubber bushing in the mounts and also likely be able to twist the springs. This could allow the axle to move a lot more than it would if nearer the connecting line. In this case the track bar would likely be of much more benefit. Of interest is that on our Chevy, the rear shackles are aimed up, not down like we all used to see in the leaf spring cars, and this places the axle centerline closer to the connecting line between the mounts.

[Roadtrek Adventuous RS1]

Originally Posted by Mat Mobile

Agreed. You don't have to do it all at once. And you will most likely be satisfied for a long time.

Actually, it's cool that you posted about the Trac Bar. I think it made a lot of people learn something new. Mself included so thanks!

Don't forget to post back later on with a more in depth review.

You're welcome...this is my first RV...and first time owning a van....I've driven them in the past.. but, not my own...

It's a new experience for me...

These guys at Super Steer in Grants Pass, since 1961... have been doing research and development for a pretty long time... they developed this unique Trac Bar themselves designed just for the Mercedes Benz Sprinter... It's not a typical off the shelf kind of product or something from Roadmaster...

You can't get this Trac Bar anywhere else.. Sure, it was expensive to to all these things..hell, if I listened to some people.. they would think my efforts was just a "waste of money" and I should have just spent the estimated $10,000 on the "air suspension".....

It was only after I had a long conversation with the Super Steer folks and my RV shop..
I was actually on the fence about the trac bar and sway bar..... BUT, I figured that this "recipe" they advised was actually going to give me the results I was looking for...

I'm taking the RV back across the USA this fall... And I'll send you a PM on how it worked out in high winds... funny how many high winds you get in the plains states... Kansas.. etc.. even in the deserts..

Didn't want to roam that far without the upgrade...

I'm done for a while.. and will just enjoy my RV ... can't worry about everything...

I'm in my late 60s... and don't expect that I'll be doing the RV thing 15 years from now...so, I just have to enjoy it right now... we'll see how that works later...