Center point suspension

redwoodin with remy · 10-30-2014, 03:10 AM

Would like to get input on the Center point airbag system. Getting a unusal amount of porpoising on my 39 mb on a 14 F 350 with 5000 pound airbags and joust bumpers.

atom ant · 10-30-2014, 04:56 AM

Boy, put your money towards the Trailair Tri-glide pin-box instead! (which I assume you don't have based on your signature pic) I get nothing - no porpoise, no chucking, just a pleasure ride! Maybe an occasional "whoop-de-do" on the frost heaves, but that's the end of it. Most pleasurable tow I have ever had. I have the same truck and airbags you do.

Not just boasting about something I paid a lot of money for either, because I didn't and I didn't even know much about it when I checked the box on the order sheet. It was just a nice surprise.

On a side note - you might check your axle weight and pin weight. Porpoising could be as sign of a light nose which could be fixed with a little reconfiguration of the cargo...

redwoodin with remy · 10-30-2014, 05:23 AM

Got a Rota-Flex on now. Had a FifthAirborne on a 2006 Jayco Talon 36 v (TRI AXLE TOYHAULER), wasn't completely sold. Also I was pulling with a 08 F 450. So....I don't know if I am missing the tri-axle or the 450. The talon also had six shocks....why don't Redwoods have them. Has anyone tried them.
Thanks atom for the comeback. Been watching your post for a while, keep up the good work!!!!

redwoodin with remy · 10-30-2014, 05:39 AM

Oh....on the light nose, these things come off the line at 14076 and only 2270 on the pin, do you have the ratio formula? As soon as the corn guys get caught up, I am going to do a scale run as I like to know where my stuff is. As a 33 year vet in some type of rv, we pack very minimal, but I am gulty of having five or so gallons of water in the black tank (and the 39 mb has two) and I carry two lights on the monitor of fresh water as we like to Sam Walton camp.

rob_fla · 10-30-2014, 11:53 AM

We still have not got the Tri Glide Pin Box ride down quite yet.
Ours rides great most of the time but on a bridge or significant bump at highway speeds, it sends us for a quite ride to the point of I have to put on brakes to calm it down.
We made several cross country trips with our previous 5th Wheel (Jayco Pinnacle) with a MorRyde Pin Box, it had a much better rough road ride than our Redwood does. The Pinnacle had a pin weight of 3,700 lbs. with a loaded weight of 15,800 lbs.
I think a lot of our problem with our 38FL is not enough Pin Weight and in some cases we are coming off the trucks overload springs and back down on them pretty hard.
We will be at our home base for about 2 month for Thanksgiving and Christmas, will look at options to improve rough ride before hitting the road again in January.

**Dave&Ginny** · 10-30-2014, 01:04 PM

I was reading on another forum that some of the folks were only running about 20 psi in their air bags. This could cause the proposing as well. I have a heavy pin weight but I get the best results in running 85-95 psi in my bags.

rob_fla · 10-30-2014, 01:08 PM

I run about 70 psi in my Air Bag, at 70 psi the shock absorber is just about fully extended when sitting still.
If I run the pressure much lower, the Air Bag / Hitch will bottom out pretty easily.

**Dave&Ginny** · 10-30-2014, 02:58 PM

Sorry...I'm referring to the "air bags" on the truck not the hitch.

0nTheRoad · 10-30-2014, 02:59 PM

The Op was about Center Point but the discussion has focused on the PinBox, two different things that could potentially have different impact on towing.

The TrailAir pin box is a huge help on smoothing out the ride in the truck by absorbing the chucking caused by opposing forces between the truck and rig, especially at bumps or bridge expansions. Finding the sweet spot is a trial and error process, some choose to gauge it by Psi some use the arrow hep box as a guide, I personally use the arrow and inflate so that the outside portion of the piston is at the lower edge of the arrow going [for the pressure geeks it is ~70PSi].

The Center Point is a replacement for the EquaFlex suspension system and uses an air bag system to reduce the shock and vibration and will smooth out the ride within the rig. Some of our forum members have opted for the Center Point, all I know of are happy with the upgrade. Others on the forum have opted for a the MorRyde IS, a total suspension replacement and those who have made this change also seem very happy with the change.

The porpoising that redwoodin with remy spoke of would most likely be be a factor of pin weight so if one of the two mods were to be chosen to address this I would think it would be the PinBox and/or getting more weight on the pin which could easily be accomplished by carrying more fresh water.

atom ant · 10-30-2014, 03:24 PM

Brian,

I'm running 4,320 lbs on the pin with water and gear, (about 3,480 without water or gear). 12,900 on the axles.

That's a 25% ratio with water, 21% without. May be a little on the heavy side, but that is kind of how Redwood designed the 36RL.

We had the 5th airborne before also - and it did well, but not as well as this Trailair.

Upgrade to the suspension - shocks or otherwise, is probably not going to impact chucking or porpoising, at least not directly.

0nTheRoad · 10-30-2014, 04:10 PM

Brian,

Just noticed you have the 39MB... my previous post saying that adding water would add weight to the pin is not going to work for you.iIf I recall correctly the MB has a different tank configuration because it has two black tanks and the fresh water tank is actually behind the axles. Assuming this is correct, adding water will actually lighten the pin weight???

rob_fla · 10-30-2014, 09:21 PM

Has anybody installed the MorRyde SRE 4000 suspension on a Redwood?
I installed it on our last 5th Wheel, made a great improvement in ride and no air bags to keep up with.
http://www.morryde.com/aftermarket/s...system-38.html

usaf1949 · 10-30-2014, 10:22 PM

I installed the Center Pint on my 36 RE and have noted a big difference in the ride with no roller coaster rides or chucking. It was well worth the investment. Had it done at Camping World in Nashville. They did excellent work and all for less than
$ 900.00. Good luck with whatever you do!

redwoodin with remy · 10-30-2014, 10:49 PM

Ahhhhhh....i get it, if the water tank is behind the axles, makes perfect sense I've had my worst problem while boondocking and carrying more water

I have been running between 50 and 65 pounds in my truck air bags if I go above 65 it seems to have a ski boat feel in the lake, truck wants to tip back and forth

I would be all over the airride pinbox if I was having a chugging problem, but it is almost non-existent.

I seen this center point system on USAF1949 RIG, it looks like a good improvement, mabye not as good as a mor ride....but price point 916.00 installed out the door. He seemed convinced and who am I to argue with a retired fly boy

Seems like I got a lot of trial and regret to do....keep firing the comments and opinions, I really appreciate all the help. Kinda like having a Redneck Camper engineering team at my side.

**Dave&Ginny** · 10-30-2014, 10:56 PM

Quote:

Originally Posted by 0nTheRoad

Brian,

Just noticed you have the 39MB... my previous post saying that adding water would add weight to the pin is not going to work for you.iIf I recall correctly the MB has a different tank configuration because it has two black tanks and the fresh water tank is actually behind the axles. Assuming this is correct, adding water will actually lighten the pin weight???

We have considered the MB as a replacement for my RL but after hearing where the water tank is......I'm not so sure. This would be a great setup for a srw truck but I enjoy the heavy pin weight that the RL has.

There have been many times where we travel with the water tank either full or close to full.

redwoodin with remy · 10-31-2014, 02:22 AM

Gonna check into the tank placement. This will actually be good as I would like to stack a pair of 8D AGM batterys in place of those "BATTERYS" that came from the factory. I installed a Zantrex 2500 inverter and I need more amps.

More water + more amps = MORE BOONDOCKING

BUT...respect to gross vehicle weight

All of yall are awesome...keep digging and THANKS!!!!

TerLar · 10-31-2014, 10:38 PM

Quote:

Originally Posted by atom ant

Boy, put your money towards the Trailair Tri-glide pin-box instead! (which I assume you don't have based on your signature pic) I get nothing - no porpoise, no chucking, just a pleasure ride! Maybe an occasional "whoop-de-do" on the frost heaves, but that's the end of it. Most pleasurable tow I have ever had. I have the same truck and airbags you do.

Not just boasting about something I paid a lot of money for either, because I didn't and I didn't even know much about it when I checked the box on the order sheet. It was just a nice surprise.

On a side note - you might check your axle weight and pin weight. Porpoising could be as sign of a light nose which could be fixed with a little reconfiguration of the cargo...

Atom Ant,you always have great input on the Forum,thanks a lot.What is the best way to determine pin weight,weigh the camper alone then hook up and just weigh the camper axels?? Larry

atom ant · 10-31-2014, 11:35 PM

Thanks Larry,
No benefit weighing the camper alone - but the truck yes. Here is what I do and I inserted my numbers so it might make a little more sense:

Weigh the whole rig so that you are seeing a weight on the trailer axles, on your drive truck axle, and your steer truck axle. (have to maneuver a bit because our trucks are a little shorter than a semi).

Weigh #1
Steer Axle 5,380 lb
Drive Axle 8,080 lb
Trailer Axle 12,900 lb
Gross Weight 26,360 lb

Pull off the scale, drop the trailer in the parking lot, then go back and weigh the truck by itself (Gross 9,140, trailer 0, drive axle 3,980, steer axle 5,160) .

Weigh #2
Steer Axle 5,160 lb
Drive Axle 3,980 lb
Trailer Axle 0 lb
Gross Weight 9,140 lb

Subtract the truck weight from the first weight with the whole rig. That sum, minus the weight originally shown on the trailer axles, is the pin weight. (Gross combined 26,360 - truck gross 9,140 - trailer axles 12,900 = pin weight 4,320)

If you can, weight your truck full of gas, expected gear, and expected passengers and then you can use that as a typical baseline for future weighs and you won't have to weigh the truck again. Key weight to look for is what is on the trailer axles and truck axle when the trailer is connected. There are maximum weights for those in both axle ratings and tire ratings.

If you simply subtract the gross truck weight from the first weight, you'll come up with the total weight of your trailer. (Gross combined 26,230 - truck gross 9,140 = trailer weight 17,090)

**piper guy** · 11-01-2014, 09:17 PM

Brad - your Dually weighs the same as mine to the pound ....

**piper guy** · 11-01-2014, 09:19 PM

I'm at 25,745. But that's with no gen. Generator going in over the winter. May need to contact you with some suggestions as I'm going to do myself. Coach does have the prep.

You may also like: