19.5 Tire Discussion

[Regcabguy]

OK here we go. Installing hellwig overload springs tomorrow and testing them out. We will see if they work better than torklift stableloads. Call me crazy but I just dont want a long bed dully when I camp mostly in the summer months and need my truck to get me to work in the winter months. I also am about to order the heavy haulaer 19.5 rims and toyo M655 tires not so much to control sway although many have reported much better driving on commercial tires with this weight but to also have my weakest point covered for weight capacity and hopefully flat tolerance.

I just installed Timbren's on my '07 with 2200# camper on the back. The truck finally handles well changing lanes,in stiff winds and turning. I already had Carli airbags and a 1 1/8" Hellwig swaybar. I'm very pleased.

 

[brillmtb1]

Helwig overloads installed. I have some adjustability I can add but ride is better. I was trying the stableloads as well and I think the overload springs work better to reduce sway that I thought a sway bar might handle but alas, it didnt. So I have added large hellwig sway bar and overloads. I already had airbags but when I put in air to level I really think it makes the ride worse. So heres my next move and please tell me what you think. I am going to REMOVE my 2 inch lift blocks up front so the rear can sit into the springs better and be closer to level. I am also ditching my old shocks and going with adjustable all the way around. I hope this will dial in my ride to closer to what I am looking for short of getting a dually. Doesnt the dually have the same springs as the SRW. I would assume that the sway left to right would be just as bad although the load carrying would be greater due to the dual tires.

I think with my heavy artic fox 811 that going back to original stock design will be better, perhaps safer. I also will be adding 19.5s when camping.

 

[AH64ID]

That is why I asked about a level kit a while back. You absolutely don’t want a level kit with a high RAW and CG. Ditching that should have been your first step and you would have saved a lot of time and money in this process. Airbags will react very different when level is 2” lower and more weight is on the OE springs.

 

[brillmtb1]

I dont doubt this will be better but my TC is sinking my current springs down 2-3 inches with the overload springs. My rationale for removing the front is to lower COG a little, return geometry to stock and perhaps that will take some stress off the front, and to better align the headlights. My stock rear leafs probably would never control this weight and probably a dually doesnt have that much more spring rating. I have heard that it may be exactly the same and that the axles in both rated the same. The tires are different with respect to load but I will correct that with the 19.5 and 4900lbs commercial tires rated for all locations and then throw on some centramatics. The sway bar is probably helping a little but it cant do more than the overloads are doing and new shocks that are adjustable will probably reduce or retard porpoising and rebound. Then its just drive like any sane experienced camper would.

I dont expect that even with a dually I would get back to the kind of lateral stability unless perhaps I did a custom 4500 flatbed kind of approach. I cant imagine that a long bed without modifications would be that dramatically different as well. Just a heavy camper. The solution to that is pull a TT or go minimalistic on the TC.

So the only extra time spent and money may be the stableloads which I left in stalled right now. If I find I dont need them will just sell at a good price, they are even the SS models.

 

[brillmtb1]

Hey, another question for you AH64ID or anyone. So the airbags when they level the truck make the experience less than optimal as you really feel the side to side sway more since the airbags are now doing more even with less air lets say. So how does the auto level on the new trucks work. Do you get the same airbag feeling. I am wondering with my experience trying different things if the standard spring pack would be better with a TC then the air levelling option.

Airbags worked great with a fifth wheel as the trailer didnt add side to side rocking like a TC does so perhaps the airlevel option would be better for fifth wheels that are heavy vs TC if it doesnt have some additional way to control sway that firestone airbags dont.

Does that make sense?

 

[lpennock]

My 2018 drw with factory air had more sway than my 06 srw until I added a roadmaster sway bar. Now my 06 did have the upper stable loads which brought in the upper overload springs earlier. The upper stable loads made as much difference with sway on the 06 as the roadmaster bar did on the 18.

I doubt the lower stable loads would work as well as the uppers did on the 06. The upper overloads are much higher spring rate than the lowers.

 

[brillmtb1]

Makes sense Lpennock. I think this is the conclusion I am coming to. I wonder how timbrens in the rear would work to assist in sway control vs air bags which I find not as good for TC as riding on air feels unstable side to side even aired down. Wonder if the timbrens would feel the same just bouncing on rubber rather than air.

 

[lpennock]

Timbren should be a little better than bags with a common filling line and about the same as bags using independent filling lines. The problem with bump stop replacement units is they are too far inboard to provide sway control. My 06 originally had something similar to Timbren and had sway. The upper stable loads cured it because they are outboard of the frame.

Similar with the 18, the bags do great for load but needed a heavy sway bar for sway control. The 2500s have a sway bar because springs or bags are inboard of the frame and don't provide sway control.

It is simple moment arm physics. Short moment arm needs more pressure to provide same counteracting force.

 

[brillmtb1]

How is your current rig set up. And yes f my tc wasn't 4000lbs and tall physics would be in my side. I am just trying to minimize the downside of getting a plush well made camper. .

 

[lpennock]

With the Roadmaster Sway bar (Item #1129-144 Rear sway bar 1 3/8 diameter (4WD) will fit both gas and diesel applications. Dually models only.) The truck can easily take turns at 10mph over the recommended speed. Wet weight of camper is right at 4klb. Feels no sway from cross winds or when passing semi's.

 

[brillmtb1]

Is yours a dually. I wonder why with my 3500-4000 k feels like it has more sway then yours. Having outboard wheels should not change sway if springs the same

 

[lpennock]

My 18 has training wheels. My 06 did not. I used the Eagle Cap 950 (Previous camper about 4K wet). The 18 has also carried the Nothern-lite. The 06 had a bit more sway do the taller sidewalls due to running 295/70-18 vs the 235/86-17 but nothing to make it feel unstable.

I really think the roadmaster sway bar is a better design than the Bigwig (unless it changed from when I looked at it). The roadmaster mounts to the shock mounts rather than clamping just outside the diff which would give it about on additional foot of moment arm on each side for control of sway.

 

[brillmtb1]

So my helwig attaches to the axle then to the frame in the same way the pics show on the roadmaster site?

 

[brillmtb1]

Nevermind my exact fitment does go to shocks. Why is that a better location

 

[lpennock]

Nevermind my exact fitment does go to shocks. Why is that a better location

Think of it this way. Grab a pencil in the middle and then press on the end. It will provide almost no resistance to twisting. Now move your grip to two location that are separated by some distance. As you press on one end the two locations try to counter the force. As you spread your grip apart the amount of force at the end required to get the pencil to rotate increases. Same thing with a sway bar as the mounting points get further apart the amount of restriction to rotation (sway) increases.

 

[brillmtb1]

It seems that the mounting points dont provide the leverage bit rater the other end of the bar and bar flex. If the roadmaster is a larger diameter that may explain the difference. I am going to give them a call. Seems helwig would have figured this out if the outbaod points were that import

 

[lpennock]

I'm not sure how much actual difference there is between the helwig mount and the roadmaster mount, I just consider the roadmaster a better design. The 1/16" additional thickness was another reason I went with the roadmaster.

One thing you may be fighting is the construction of the AF vs the Eagle Cap and Northern-Lite I had. Looking at the spec for the AF it is 10' with AC where as the NL is 9' and the EC was slightly shorter then the NL. So just the additional height is going to result in more sway.

 

[NIsaacs]

That is why I asked about a level kit a while back. You absolutely don’t want a level kit with a high RAW and CG. Ditching that should have been your first step and you would have saved a lot of time and money in this process. Airbags will react very different when level is 2” lower and more weight is on the OE springs.

I dont doubt this will be better but my TC is sinking my current springs down 2-3 inches with the overload springs.

Thats why you don't want a front end level kit. If the truck starts out level and you add weight, now the rear is sagging and you are adding air to the air bags to bring it back level. Now the springs have the same weight on them as an empty truck, all the weight is on the bags.

With the stock front to back rake, adding weight now levels the truck. The three inch drop on the rear is now making the truck level and the springs are carrying the weight, not the air bags. If the truck is slightly low, now you add air to bring it level.

The long bed truck will handle the same weight better because of the longer wheel base. It will have about 18" more front end leverage against the rear overhang you are experiencing.

 

[AH64ID]

Hey, another question for you AH64ID or anyone. So the airbags when they level the truck make the experience less than optimal as you really feel the side to side sway more since the airbags are now doing more even with less air lets say. So how does the auto level on the new trucks work. Do you get the same airbag feeling. I am wondering with my experience trying different things if the standard spring pack would be better with a TC then the air levelling option.

Airbags worked great with a fifth wheel as the trailer didnt add side to side rocking like a TC does so perhaps the airlevel option would be better for fifth wheels that are heavy vs TC if it doesnt have some additional way to control sway that firestone airbags dont.

Does that make sense?

Are the airbags plumed together or separately?

The factory auto-level did better with 2 ATV's above the bedrails than my 05 stock or with just airbags. I put the smaller Hellwig swaybar on the 05 and it was super stable with that setup. When I had a 2" level on the 05 it took too much air in the airbags and wasn't as stable as it was after dropping to a 1" level and being allowed
to put more weight on the OE springs the airbags took less air and the difference was huge. I had upper overloads but they were not ever engaged statically.

Dad's 06 had a 2" level and took too much air in the airbags to hold level with his Lance and the handling suffered, thou I couldn't ever get him to remove the level kit. That was a 2500 without upper overloads so just airbags and springs.

The added height from leveling with a 2" level make a bigger difference that people think, both in increased CG height as well as weigh being removed from the OE springs via airbags.

 

[brillmtb1]

thanks, all makes sense. Now I have to figure out if I take off the front level kit if my 295/65-20s will hit. Man, one thing or another still but I will get this dialed in.