Rougher ride than expected

[jsalbre]

Ok towing and suspension gurus, I need your help.

Unloaded my truck rides exceptionally well for an HD truck.

We’ve upgraded our trailer to a Brinkley Z Air 297, and the ride in the truck is beating us up unless the road is glass-smooth. Obviously it’s an HD truck, and I’m aware it’s going to be a bit rougher with a lot of weight, but this borders on unbearable.

It’s 35’ long and my scale weights are as follows:
Truck only, but fully loaded:
Steer: 4580
Drive: 3760

Hooked up, no WDH:
Steer: 4040
Drive: 5780
Trailer: 10680

I’m not going to bother posting my with WDH numbers as they’re wrong, because I had the WDH set up poorly and way over-adjusted when I ran across the scale. I’ve since corrected it by measuring tape, but haven’t re-scaled.

I’m running a B&W Continuum hitch, so adjustments are extremely easy to do.

All in we’re at 20500 lbs going down the road. FWIW, the Hemi is handling this just fine. I’ve had no issue with power or engine braking through the mountain passes. Fuel economy is only about .5 mpg less than it was with my previous 7k lbs trailer.

I’m running Thuren suspension front and rear with Fox 2.5” with DSC, so the shocks are adjustable. Our first tow I didn’t have airbags in yet, so the squat was terrible. I ran with the shocks relatively stiff to improve stability. I figured this would be the problem.

I’ve since installed Airlift LoadLifter 5000 Ultimate (internal bump stops) kit, with Daystar cradles. With the airbags at 35 PSI (giving about 3/4” of squat w/o WDH) it sits exactly as I want it, and feels very stable, but still beat us up terribly, even with the shocks set almost all the way soft.

Loaded up I’m running 40PSI in the front tires and 50 in the rear.

I’ve ridden in U-Haul trucks that were smoother.

Help me solve this before my spine and kidneys revolt.

 

[Deleted member 47449]

It might be the trailer. On our 2023 ORV Backcountry Series one of the axles was damaged during manufacturing. I found it just prior to the 1 year warranty expired when I removed a tire. The axle assembly was entirely replaced.

 

[johnmyster]

That is a heavy, and long trailer...giving it large rotational inertia. Sounds like, it's throwing the truck around. Our rig is similar in that regard. It's one thing to add mass. It's another to add mass on a big long lever to the truck, especially when you've also made the tires more squishy, suspension more squishy, etc.

The spring rate on your long travel rear coils isn't enough to control the movement. Airbags should help offset this, but you might consider swapping back to factory rear coils. Truck tire air pressures also sound a little low, but the big thing...

Your shocks. Full soft is the wrong direction. You need more dampening. Lots more. You need firmer shocks (especially on the rear) to control movement. You've added mass (trailer) and spring rate (airbags) to the system, so now you need more dampening to control oscillation. From whatever your happy settings are unloaded, add a few clicks on the front and even more on the rear. Back off from there to taste. If those fancypants shocks have separate rebound and compression adjustment, don't be afraid of compression dampening. Low speed dampening. All the low speed dampening.

The WDH means the front axle helps resist trailer movement too, so the additional dampening there is helpful. That said, don't overdo WDH tensioning. The truck needs to be able to move.

On the camper - revisit tire pressure there too. Try to add more tongue weight (heavy gear in front.) 12% tongue is a little light for that much rig. (Ours is 17%.) Consider adding shocks if the camper doesn't already have them. They're cheap and it won't hurt, but honestly I didn't notice much improvement when I added them.

On second thought, I thought you discussed your suspension mods a few months ago, but I don't remember the target travel trailer being quite that big/heavy.

Thread 'Talk me out of my suspension plans'

Apr 1, 2025

I’m getting ready to do suspension, wheels, and tires on my ‘23 Rebel Hemi.

After long calls with all the big suspension companies and a few shops I’ve decided to go Thuren for the suspension, and I’m going to go with their 2” front lift coils, the .5” long travel rear coil kit, and the front and rear track bars.

I’m strongly leaning towards the Fox 2.5 DSC shocks, but I’m struggling to not get the Fox 2.0 (RR front, IFP rear), because those are almost $2400 cheaper. I know the DSC is going to be better, but is it enough for the cost difference? Talk me out of the 2.5s and into the 2.0s...

• jsalbre
• Replies: 19
• Forum: Suspension

I think consensus was that the off-road suspension would be a compromise for towing. Atleast, that's what it looks like I said.

View attachment 87989

Wow. What a waste of an AI guess. It was wrong about...everything.

 

[jsalbre]

Thanks for the replies. I appreciate the input. Some additional info to clarify, and maybe help a bit more:

The “Model Z Air” is not on air suspension, it’s just that the “Model Z” is their 5th wheel line, and the “Z Air” is similarly built travel trailers. It’s all leaf springs, on 7k# Curt axles.

The trailer does have shocks on both ends of both axles, and also have RoadArmor shock absorbing equalizers and wet bolts.

I do run the shocks about mid level when driving around unloaded and tightened up a couple clicks when towing. I just happened to have it set soft when I finished up the airbags as I’d just been testing some new settings and had to love in a rush. It was a short move with no highway so I wasn’t too concerned with handling. I was just surprised that it felt just as bad with them soft as it did with them set where I thought they should be.

The airbags add significant stability and lean resistance since they’re outboard of the existing coils.

I’m running tire pressures based on the Falken Load Inflation chart. https://www.falkentire.com/load-inflation
The tires are rated at 2625# per tire at 40PSI and 3000# per tire at 50PSI, so I’m actually running a bit higher than required for the load. That could account for some of the roughness, since by load I should be closer to 35/45 F/R.

Agreed that the suspension is a compromise for towing, but the airbags should be making up for any added softness in the rear. The front is sitting at nearly the same weight (less than 100# difference) it was with my last trailer, as that trailer was very nose heavy.

The feeling isn’t like we’re bouncing around too long after a bump, like I’d expect if it was un/underdamped (we don’t look like an old Cadillac going down the road), but more like it’s all too “hard”. Maybe I’m interpreting the feeling wrong though?

 

[wrvond]

So, you are adding 2000 pounds to the hitch so you should be using 2000 pound bars on your hitch. What is your process? I recommend hooking up then inflating the air bags to get back to the level you want. Then adjust the WDH. You want to be sure the bars aren't too tight - this can lead to damage of the trailer frame.
Have you tried towing the camper with the bags inflated without the WDH bars installed? In the past, when I felt the ride was too rough, loosening tension on the bars invariably resulted in a much smoother ride.

 

[jsalbre]

So, you are adding 2000 pounds to the hitch so you should be using 2000 pound bars on your hitch. What is your process? I recommend hooking up then inflating the air bags to get back to the level you want. Then adjust the WDH. You want to be sure the bars aren't too tight - this can lead to damage of the trailer frame.
Have you tried towing the camper with the bags inflated without the WDH bars installed? In the past, when I felt the ride was too rough, loosening tension on the bars invariably resulted in a much smoother ride.

The hitch is a Continuum, there’s no bars per-se, just a carbon fiber spring and a hydraulic ram to adjust tension.

My adjustment method has always been to take front ride height measurements unhooked, and hooked up, and then use the WDH to get 50% load restoration, as described in the manual.

When I towed with the airbags on (it’s only been one tow like that so far, and only for about 20 miles), I aired the bags up to get the rear ride height about an inch below unloaded, then adjusted the WDH.

 

[jsalbre]

I’m going to have to do some re-weighing. If that 2000# tongue weight is accurate then I have a problem, as I’ve just checked and the towing chart says the hitch is rated to a max of 1800#.

It’s obviously lower than that with WDH engaged, but I’m thinking it should be under that before it’s engaged as well.

@wrvond’s post plus my late-night-brain had me worried, but I went over the numbers again and the tongue weight is 1480#, not 2000#.

4040+5780=9,820 (hitched up)
4580+3760=8,340 (truck alone)
9820-8340=1,480.

 

[johnmyster]

I know I jumped to the conclusion that the trailer is throwing the truck around, but I just can't imagine how the ride became unbearably harsh. Maybe I'm wrong on all fronts.

1) Overtensioned WD can make the ride poor, but undertensioned can make handling squirrelly. I've heard other Continuum users complain about ride too harsh, solved by reduced tension.
2) More low speed dampening, especially on the back axle, is what controls see-saw motion of that long/heavy trailer.
3) 1500# tongue weight is probably happy, but per my experience I wouldn't be afraid of more.
4) I'm guessing you still have plenty of travel remaining on the rear before jounce bumper contact?
5) It doesn't sound like you're overdoing airbags but I wonder if they are too progressive.
6) It sounds like you are trying to run load inflation minimum for ride, but keep in mind that's a minimum. More will reduce sidewall squirm and keep the trailer from throwing the truck around. Your rear axle is nearly 6000 pounds, don't be afraid of some air.

Are those fancy fox shocks position sensitive? If so, might need to allow more rear suspension compression to get/keep them in the high dampening region. (Less airbag.)

 

[AH64ID]

@wrvond’s post plus my late-night-brain had me worried, but I went over the numbers again and the tongue weight is 1480#, not 2000#.

4040+5780=9,820 (hitched up)
4580+3760=8,340 (truck alone)
9820-8340=1,480.

Are those hitches numbers with the WDH hooked up?



As far as the airbags your situation with otter springs is a little different than most, but you want to make sure that the airbags aren’t reducing the effectiveness of the WDH. It doesn’t sound like they are in your case, but definitely something to watch for.

 

[wrvond]

I’m going to have to do some re-weighing. If that 2000# tongue weight is accurate then I have a problem, as I’ve just checked and the towing chart says the hitch is rated to a max of 1800#.

It’s obviously lower than that with WDH engaged, but I’m thinking it should be under that before it’s engaged as well.

@wrvond’s post plus my late-night-brain had me worried, but I went over the numbers again and the tongue weight is 1480#, not 2000#.

4040+5780=9,820 (hitched up)
4580+3760=8,340 (truck alone)
9820-8340=1,480.

Sorry about that. Clearly some of that 2000 pounds is weight shifted rearward from the front axle and is not all on the hitch.

 

[jsalbre]

I know I jumped to the conclusion that the trailer is throwing the truck around, but I just can't imagine how the ride became unbearably harsh. Maybe I'm wrong on all fronts.

1) Overtensioned WD can make the ride poor, but undertensioned can make handling squirrelly. I've heard other Continuum users complain about ride too harsh, solved by reduced tension.
2) More low speed dampening, especially on the back axle, is what controls see-saw motion of that long/heavy trailer.
3) 1500# tongue weight is probably happy, but per my experience I wouldn't be afraid of more.
4) I'm guessing you still have plenty of travel remaining on the rear before jounce bumper contact?
5) It doesn't sound like you're overdoing airbags but I wonder if they are too progressive.
6) It sounds like you are trying to run load inflation minimum for ride, but keep in mind that's a minimum. More will reduce sidewall squirm and keep the trailer from throwing the truck around. Your rear axle is nearly 6000 pounds, don't be afraid of some air.

Are those fancy fox shocks position sensitive? If so, might need to allow more rear suspension compression to get/keep them in the high dampening region. (Less airbag.)

1) I definitely had it overtensioned on my first tow (pre-airbags), and it was squirrelly. Here’s the number from that scale session that I said I wasn’t going to bother providing above, but I guess it’s useful info anyway:
Steer: 4440
Drive: 5220
Trailer: 10840
As mentioned, I changed the adjustment the next morning when my brain was functioning again, and have not re-scaled since then.
2) Maybe I need to crank that up some. It didn’t “feel” like see-sawing and I couldn’t see any from the driver’s seat, but that doesn’t mean it wasn’t there.
3) I’d like to get it higher, and it will go up some when I get my batteries and solar installed, but I’m trying to be careful to keep it under the 1600# limit for the hitch.
4) Before airbags I had about 1/2” before hitting the bump stops, so I’m sure I was touching them over bumps, and that contributed to some harshness. With the airbags I was at nearly stock distance with them inflated and WDH engaged.
5) Maybe?
6) I try to keep it a bit above minimum. Like I said, by weight alone I could handle it with 5PSI less front and rear. I was concerned going too high would make the ride even harsher.

I don’t believe the shocks are position sensitive, but I can’t find anything definitive either way. Fox calls out that some of their other lines are, so I’d assume these are not since it isn’t mentioned.

Fox says that the “factory setting” for these shocks is both low and high speed compression set to 3 clicks, which is slightly stiffer than stock from what I’ve read. I’ve been mostly driving around on road with front at 6 low and 2 high, and rear at 4 low and 2 high. Towing I’ve had it both front and rear at 7 low and 3 high. They can be set at up to 10 clicks of low speed adjustment and up to 12 of high speed, so I have more room to play with. Maybe I need to crank them up more? I suppose since these are Thuren-tuned I could give them a call.

Are those hitches numbers with the WDH hooked up?



As far as the airbags your situation with otter springs is a little different than most, but you want to make sure that the airbags aren’t reducing the effectiveness of the WDH. It doesn’t sound like they are in your case, but definitely something to watch for.

The numbers in my original post are without WDH engaged. I posted the with WDH numbers in this reply above, but they’re not accurate post-airbag installation as I set it up differently once I crunched the numbers.

I think I’m doing it right with the airbags, but maybe I have too much air in them.

 

[jsalbre]

Some updates: turning the shock damping up definitely helped with some of the roughness, but there’s still a pretty extreme lack of ride quality on anything that isn’t pretty smooth once we get up to highway speeds. At this point I’m wondering if there’s someone I can pay to help me figure this out. It’s absolutely killing my wife’s back.

On the plus side, the Hemi has no concerns powering this thing up hills at 65mph in 100°+ heat. It does drink the gas like there’s no tomorrow though.

 

[Lonestar]

Depending on the amount of air in the bags it can make the ride much more harsh

 

[jsalbre]

Depending on the amount of air in the bags it can make the ride much more harsh

Yes, this is a given, and discussed above. Having them at 30-35 (unloaded) seems to improve ride quality over empty, and brings the rear of the truck to about an inch below empty ride height. I haven’t tried any more air as that would have the airbags holding almost all the weight with the actual springs doing very little.

 

[johnmyster]

This guy is a novice expert YouTuber, not a suspension engineer, but has tested and reviewed lots of hitches with medium TTs behind HD trucks. (Your TT is heavier than what he typically has.) He initially had a bad experience with the continuum. B&W helped him correct his setup. He later did another video when they got a larger camper and was very critical again.

 

[AH64ID]

Some updates: turning the shock damping up definitely helped with some of the roughness, but there’s still a pretty extreme lack of ride quality on anything that isn’t pretty smooth once we get up to highway speeds. At this point I’m wondering if there’s someone I can pay to help me figure this out. It’s absolutely killing my wife’s back.

On the plus side, the Hemi has no concerns powering this thing up hills at 65mph in 100°+ heat. It does drink the gas like there’s no tomorrow though.

I have to wonder if it's expectation management or actually something wrong. I wouldn't classify the stock 2500 ride as hard while towing even on rough roads and that's what you wanted to improve, right?

Yes, this is a given, and discussed above. Having them at 30-35 (unloaded) seems to improve ride quality over empty, and brings the rear of the truck to about an inch below empty ride height. I haven’t tried any more air as that would have the airbags holding almost all the weight with the actual springs doing very little.

What is the pressure loaded? 30-35 empty will be a bit more air when loaded.

 

[johnmyster]

I have to wonder if it's expectation management

Even more challenging is spousal expectation management after all the money spent on suspension goodies and an exceptionally nice camper.

 

[jsalbre]

This guy is a novice expert YouTuber, not a suspension engineer, but has tested and reviewed lots of hitches with medium TTs behind HD trucks. (Your TT is heavier than what he typically has.) He initially had a bad experience with the continuum. B&W helped him correct his setup. He later did another video when they got a larger camper and was very critical again.

I’ll definitely give that a watch when I have a few minutes. I ordered an Equalizer that delivered today and I’m going to swap that out. It’s mostly because the Continuum has almost no resistance to sway and basically feels like towing straight on the ball (aside from the WD itself of course), while all of our previous Equalizers have eliminated all “wiggle”.

 

[jsalbre]

I have to wonder if it's expectation management or actually something wrong. I wouldn't classify the stock 2500 ride as hard while towing even on rough roads and that's what you wanted to improve, right?



What is the pressure loaded? 30-35 empty will be a bit more air when loaded.

The stock 2500 ride is pretty good on most roads, better once the front sway bar came off, and excellent once the Thuren/Fox suspension went on. When I say it’s rough towing this trailer I mean that on I-86 and I-84 the other day I was struggling to keep my coffee down on road surfaces that I barely noticed with our last trailer.

Loaded the airbags are sitting around 50-55ish pounds.

 

[jsalbre]

Even more challenging is spousal expectation management after all the money spent on suspension goodies and an exceptionally nice camper.

She definitely has high expectations, but she’s not unfamiliar with the way an HD truck rides, and doesn’t expect perfection, just not pain. It’s hurting me to drive too, and I’m a mountain biker so I willingly subject myself to abuse all the time.