SRW vs. DRW

[snoking]

Me thinks, that those of us who have never towed with a DRW TV maybe do not understand the difference in stability that training wheels add!!!!
Chris

[Chief409]

Me thinks, that those of us who have never towed with a DRW TV maybe do not understand the difference in stability that training wheels add!!!!
Chris

Something to think about. In the 1970's the trucking industry started using wide single rear wheels instead of duals on semi's. This ended after a few years because of stability issues. Now the only big rigs with single wheels on the rear in wide use are cement trucks, which don't go very far from home, or tow trailers.

[snoking]

Well, almost true. There is a new round of singles that have been out there for a few years. I see a rig on the road now and then with them. Michelin calls them wide base. 14" wide rim. 445/65R22.5, 12800/130lbs, dia 45.8. So 12800 x 2 = 25600 lb rating on a single axle.

Our local log trucks only made a few trips for Port Angeles to Forks, Wa in the 1970's before removing the wide singles.

Chris

[Mike Clay]

Ok now im confused , Yes Matt i am Lets take the NASCAR analogy what happens if they blow a front tire. Now I am speaking Chevy again but with all the new stabilitrak trailer sway control and such I really feel the technology has come a long way in just a few years
http://www.youtube.com/watch?v=fckqWn608SA Arguments can go both ways all day long its whatever floats your boat maybe I have been lucky but with this new truck towing the other day in 35 mph cross winds I had no issues at all.

[Don Wilson]

I don't know about the technical stuff you guys are talking about but can only go with my own experience.

Towing I have towed my 29 foot Cardinal with both a 3/4 ton single rear wheel and my 1 ton dually on the same roads like I-40 in New Mexico and Arizona with some major cross winds and I can tell you there is a major difference in stability with the dually over the SRW. Also the difference on rough roads in the stability of not feeling like the trailer might rock over with the dually. I am thinking about the road through Monticello Utah coming from Colorado the past few times I have gone through there. Mike knows what I am talking about .

Blowouts This past April I ran over a piece of metal and blew both rear tires on the drivers side and the control when that happened with the dually is better than what it was just having a flat on the 3/4 ton SRW.

Don

[bigbunkhouse]

Ok now we are in physics talk! Given all else equal, adding the "training wheels cannot actually increase stability, why you ask------the frame, springs, and center of mass are the factors acting on the stability of the truck. the Spring centers from the center of the truck is constant, assume 2.5 ft from the center of the frame, and assume a center of mass 2ft above the center of the axle. now assume a 2000# side load under cornering at the center of mass this creates a moment force or torque on the axle trying to push one side into the road and the other side lift up of 4000ftlb around the center of the axle(2000# times 2ft above the axle). Now 4000ftlb divided by 2.5 ft from the center of frame to the spring center gives an added 1600# force on the spring. This also adds 1600# of weight to the tires because even tho the tires are further away than the springs the springs are what takes the weight. The difference with the training wheels comes in with the tires themselves, the side load of 2000# tries to fold the tire over causing flex in the tire, but when the duals are added the "wiggle" of the tires is split between 2 tires, also the added 1600# of weight added to the tires will be split between 2 causing less deflection. This is a "simplified version, neglecting the effects of the swaybar and shocks, plus the fact that the dual wheels can actually cause more spring deflection because being wider the effective torque arm formed buy the distance from the center of the truck to the outside of the tires is longer on a dually, this has the same efffect as adding say another foot to your lever so in the above example assuming no deflection in the tires the dually would act 1600# x 3.75 ft (distance from truck center to outside of tire) or 6000ftlb back to the chassis while the single would only add 1600# x 3ft (distance from truck center to outside of tire) or 4800ftlb back to the chassis. This could cause more deflection in the suspension but since it is absorbed by the deflection in the tires it is almost neglegeable.

Anybody want a diagram with Force vectors ???

There I go again "the ramblin man"

[bigbunkhouse]

I am young and supposed to love this new technology bling but the electronic stability, traction control, etc worry me, because if that is what you rely onto save your rear then what happens when a fuse blows???

[Mike Clay]

Same thing that happens if you lose your brakes or break a drive line or on and on come on now any number of things can happen. The most important thing is you are not over weight for your tow rig the rest is creature comfort and preference.

[rwlouks]

I am young and supposed to love this new technology bling but the electronic stability, traction control, etc worry me, because if that is what you rely onto save your rear then what happens when a fuse blows???

The short answer is 'the truck won't start with a blown fuse so you don't have to worry about the rest'

The long answer is I think it will be just like all of the technology advances in vehicles like fuel injection, electronic ignition, engine control modules, anti-lock brakes, .... it's here to stay and hopefully it will keep more people from getting into those situations. (and this coming from someone who only switched to automatic transmissions when they wouldn't let me get a manual in my company cars anymore)

[bigbunkhouse]

Yor MECHANICAL parts are one thing, what I am talking about is the fact that people abuse the technology, for instance, last winter a woman in an AWD suv with traction control, stability control, toaster, etc who ran offthe road in a snow storm at 45 mph in a 25 zone and hit a house . She told my buddy, the officer at the scene " I dont understand why this happened, I have traction control! I think I'm gonna sue BMW, this thing should never loose traction!". Back in the days of rear wheel drive, people drove in the snow with caution, mostly, now how many of us have been passed by an awd something at twice the speed limit in a blizzard just to see them off the road 2 miles ahead? My wife works with the state troopers and they say that most accidents in bad weather or hazardous road conditions come from people thinking their vehicle will save them either thru anti-lock, trac control, stab control or air bags. I am affraid that the anti sway for the trailers will have many throwing caution to the wind and forgetting you still have to drive, then when they pass a major power line crossing on an interstate and a 60mph draft is screaming across the highway they will expect the truck to handle it.
Dont get me wrong, for the majority, all these things are blessings, for instance coil on plug ignition, you can loose a few coils and still get home where as if you have a distributor and a single coil and it goes bad your stuck. And for the situation that arises where the "electronic driver" is an honest life saver for that unexpected incident, I thank modern technology. I just think we are asking for trouble when we have cars that slow down automatically when we tailgate because of the poeple who say" my car will keep me out of trouble"

[bigbunkhouse]

sorry for rambling, it is the people who are the problem not the technology!!!

and they fire me up

[bop11]

That lady sounds like the guy who bought the new Winnebago. Got on the freeway, set the cruise and got up to go make a sandwich and crash
The guy sued and won. I've heard that there is now some mandated warning in motorhomes stating "leaving the drivers seat during travel will result in a crash" or something like that.

Bill

[campswithcritters]

Could not find a Freightliner M2 with SRW when I was looking, so bought the dually!

[Chief409]

A year or so ago I was at the Chevron station by the house and a KW 3 axle rig pulled in with a big 5er Toy Hauler, at least 40'. I talked to the owner, the KW is his on the road rig, he just added an RV plug to the KW to haul the Toy Hauler, said the trailer king pin works fine with the KW's hitch, but it needed a larger bearing plate, so he welded additional plates along the sides.

Now that is what I call a Tow Vehicle!

[campswithcritters]

A KW would be nice, but I love the looks of an old long nose Pete! One of these days!