Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: dans96u295ft on April 28, 2021, 12:57:02 pm

Title: New airbags great ride quality
Post by: dans96u295ft on April 28, 2021, 12:57:02 pm
Drove the FT over to Utah with the new airbags installed. Rides so mush better, Even the shocks work better now. The originals must have been very hard. Continentals seem great
Title: Re: New airbags great ride quality
Post by: Pierce & Gaylie Stewart on April 28, 2021, 01:05:59 pm
Unless you had one air bag that had a leak, the ride should be dependent only on the volume of air in the bag and if all bags have the same volume, the ride should be the same. The rubber bag itself should have no effect on the ride. You can check this with new bags on the ground. Stick a knee on one and it's only the restricted air opening that keeps it from instantly collapsing. The half dozen or so brands for our coaches are all designed to have the same amount of air capacity.

Now, if you had a bad bag with a leak in one corner of the coach, that could give a funky ride that would be fixed with a new bag(s).

Pierce
Title: Re: New airbags great ride quality
Post by: wolfe10 on April 28, 2021, 01:10:40 pm
OR if you properly set RIDE HEIGHT after installing the new bags and it was not to spec with the old ones.
Title: Re: New airbags great ride quality
Post by: oldmattb on April 28, 2021, 01:49:56 pm
Or...

Someone put tire leak sealer in them!
Title: Re: New airbags great ride quality
Post by: dsd on April 28, 2021, 04:11:23 pm
Colorado air has different effect on bags, it's thinner. Everyone knows that. Glad to hear your pleased with your ride. That's all that matters 😉
Scott
Title: Re: New airbags great ride quality
Post by: wolfe10 on April 28, 2021, 04:16:13 pm
Colorado air has different effect on bags, it's thinner. Everyone knows that.
Scott

Rocky Mountain HIGH??
Title: Re: New airbags great ride quality
Post by: gracerace on April 28, 2021, 04:23:28 pm
Yup, just like a washed car, runs so much better...LOL

Glad you are happy.Money well spent.

Chris
Title: Re: New airbags great ride quality
Post by: Travelin' Man (RIP) on April 28, 2021, 05:14:28 pm

Was there ever any doubt?
Title: Re: New airbags great ride quality
Post by: Michelle on April 28, 2021, 06:10:50 pm
Unless you had one air bag that had a leak, the ride should be dependent only on the volume of air in the bag and if all bags have the same volume, the ride should be the same. The rubber bag itself should have no effect on the ride.


You'd think, but we had the same experience when we replaced our coach's airbags.
Title: Re: New airbags great ride quality
Post by: Doug W. on April 28, 2021, 06:57:45 pm
You'd think, but we had the same experience when we replaced our coach's airbags.
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Here is a post after replacing airbags 8 months ago.... 


"Just replaced my original 24 yr. old Firestone air bags with these, no downside to which I can see. My old ones still looked pretty good considering there age, I'm sure they would have lasted a few more years. The ride with the new Contitech bags is great,  seems a bit tighter.  Glad I did it and hope they give good service like the Originals."
Title: Re: New airbags great ride quality
Post by: Pierce & Gaylie Stewart on April 28, 2021, 07:12:29 pm
A little "tighter" ride could be more volume in the bags themselves. Might be fun to flatten each one and then introduce a measured amount of air in each one and see if there was any difference. Seems as if that could be the only possible difference.

Pierce
Title: Re: New airbags great ride quality
Post by: fourdayoff on April 28, 2021, 08:08:03 pm
I'm with Brett on this one.  8)
Title: Re: New airbags great ride quality
Post by: bbeane on April 28, 2021, 08:35:12 pm
Changed mine 7 years ago, couldn't tell the difference, but I used Florida air 😎🍺
Title: Re: New airbags great ride quality
Post by: Dub on April 28, 2021, 09:39:00 pm
Afraid it's imagination but if you feel better about it that's all that matters. Happiness happens in ones mind. Don't let us be a drag. Happy Happy.
Title: Re: New airbags great ride quality
Post by: Dub on April 28, 2021, 09:42:53 pm
 
A little "tighter" ride could be more volume in the bags themselves. Might be fun to flatten each one and then introduce a measured amount of air in each one and see if there was any difference. Seems as if that could be the only possible difference.

Pierce
The mans at a happy spot now I don't believe I would go to that much trouble to up root my happiness P.
Title: Re: New airbags great ride quality
Post by: dans96u295ft on April 28, 2021, 10:39:52 pm
I made the same drive as always, but if you think it's phony, go ahead. I knows what I knows and I feel what I feels!!! It's better and I'm sticking to it
Title: Re: New airbags great ride quality
Post by: Elliott on April 28, 2021, 10:56:46 pm
I made the same drive as always, but if you think it's phony, go ahead. I knows what I knows and I feel what I feels!!! It's better and I'm sticking to it
It sounds like a exceptional value from your time and money spent then and that's all that matters  ^.^d
Title: Re: New airbags great ride quality
Post by: Michelle on April 29, 2021, 09:57:42 am
A little "tighter" ride could be more volume in the bags themselves. Might be fun to flatten each one and then introduce a measured amount of air in each one and see if there was any difference. Seems as if that could be the only possible difference.

Ozone, heat, repeated mechanical stresses...

A Guide to Rubber Degradation & Rubber Deterioration Causes (https://www.martins-rubber.co.uk/blog/what-causes-rubber-to-deteriorate/#:~:text=Most%20elastomers%20undergo%20rubber%20degradation,oxygen%20)(ozone)%20and%20heat.&text=Hardening%20is%20more%20common%20because,the%20flexibility%20of%20the%20rubber.

Degradation of Rubber (http://polymerdatabase.com/polymer%20chemistry/Thermal%20Degradation%20Elastomers.html)

Care of Objects Made from Rubber and Plastic – Canadian Conservation... (https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/canadian-conservation-institute-notes/care-rubber-plastic.html)

You see this in virtually any rubber product.  True, the inside of the airbag is more protected than a tire, but its materials still age out and experience plastic deformation.  Consider the lowly rubber band and how a 10 year old one becomes brittle and "dried out".
Title: Re: New airbags great ride quality
Post by: DavidS on April 29, 2021, 10:07:31 am
The new bags didnt have the movement when parked as the old ones... Old ones allowed a lot of movement when inside the coach when parked... THey were a little stiff at first.. Its all plush now.. ^.^d
Title: Re: New airbags great ride quality
Post by: Pierce & Gaylie Stewart on April 29, 2021, 10:18:01 am
Six of our eight air bags are OEM and 29 years old. Both air bags that developed leaks didn't have any rubber on the part facing the tires. Probably more flexible without the rubber on the outside. The inside looked like new on the bad bags. Road spray takes the rubber off the bottom of the bags at the big fold where they sit when there is no air.

Wondering if sitting in a compressed state makes them any less/more stiff than a new bag. Or is it the endorphins from the Saturday wash and vacuum? :D

Pierce
Title: Re: New airbags great ride quality
Post by: dsd on April 29, 2021, 10:49:02 am
Ozone, heat, repeated mechanical stresses...

You see this in virtually any rubber product.  True, the inside of the airbag is more protected than a tire, but its materials still age out and experience plastic deformation.  Consider the lowly rubber band and how a 10 year old one becomes brittle and "dried out".
But airbags don't function the same as tires. The airbag doesn't stretch and relax by design. They contain the air and without expansion/stretching change length  by load change controlled by ride height valves and rolling inside themselves. They would fail much sooner if they were stretching and relaxing during use like a tire. Think of them as a steel cylinder with a piston pushing in and out. They do the same function without a seal at the piston leaking. Yes the pressure inside changes on demand but the chamber size stays relatively the same. "If" the bags stretch during life the area would increase making the ratio change and they would be softer. New would be smaller and run higher pressures and be stiffer. You never hear about airbags getting oversized before failure? They get pin holes leaks from a end of life failure.
Scott
Title: Re: New airbags great ride quality
Post by: Pierce & Gaylie Stewart on April 29, 2021, 12:17:56 pm
No, they can't increase in diameter or the tires would hit them and the cords inside keep them from stretching as well as expanding. The pressure chamber volume does change a bit as the folds in the side disappear as pressure increases to level the coach on the low side but not much. I expect the biggest difference in ride and bag pressure would be from operator loading. A full timer with lots of parts, canned goods plus full water tank, diesel, propane is going to be a bit stiffer than a light coach.  Here is a photo of an old air bag. Still hanging in there but you can see the cords. Dense cords are the reason the new will be the same diameter as the old. Reminds me of my tires when I was a kid.

Pierce
Title: Re: New airbags great ride quality
Post by: gracerace on April 29, 2021, 12:36:14 pm
No, they can't increase in diameter or the tires would hit them and the cords inside keep them from stretching as well as expanding. The pressure chamber volume does change a bit as the folds in the side disappear as pressure increases to level the coach on the low side but not much. I expect the biggest difference in ride and bag pressure would be from operator loading. A full timer with lots of parts, canned goods plus full water tank, diesel, propane is going to be a bit stiffer than a light coach.  Here is a photo of an old air bag. Still hanging in there but you can see the cords. Dense cords are the reason the new will be the same diameter as the old. Reminds me of my tires when I was a kid.

Pierce
YIKES!

Our 24 yr old bags, still alive and well.

Protectant 303 is your friend. That and keeping the pads clean and painted.

The wet stuff you see is Blaster, was getting ready to change fronts.

Don't plan to change backs, I carry a. spare, an all the tools and hardware to change.

Chris
Title: Re: New airbags great ride quality
Post by: Pierce & Gaylie Stewart on April 29, 2021, 01:18:22 pm
Chris, looks as if you also have a pretty rust free coach. Sure makes working on them a lot easier and less often.

I've sprayed ours but think our dirt and gravel roads have taken their toll. I've just replaced all the tires except for one Firestone. It's looks absolutely like new unlike the Coopers that cracked like crazy. Bridgestone-Firestone sure make great casings.

This bag is a rear bag that gets all the spray from the tires. The others look pretty good and not planning to replace any unless they start leaking. I do have two spares and the tools to change them plus tubeless tire plugs. But I won't do the green slime and call it a day. :))

Next year is our Pearl anniversary for the coach ('93 but made in '92) and planning on a big party. Hope all the air bags can make it.

Pierce