Aug-22-2014 10:28 AM
Aug-27-2014 10:29 AM
Ron Gratz wrote:myredracer wrote:According to this ROT (rule of thumb), Suburbans (including 3/4 ton Suburbans) should not be used to tow trailers which are longer than 25'.
The rule of thumb below to minimize sway has been around for a number of years (from David's RV Tips). I've seen it elsewhere too. Doesn't seem to come up much. If the Armada wheelbase is 123", the max. TT would be 23', well under what the TT appears to be.
The First Guideline
(This guideline was first used by the RV Consumers Group rv.org)
For the first 110" of wheelbase, this allows you 20' of trailer.
For each additional 4" of wheelbase, this gets you 1' more of trailer.
Wheelbase / Trailer length
110" = 20'
114" = 21'
118" = 22'
and so on
No one seems to be able to provide any information about how the numbers were derived. And, IMO, no one has presented any convincing arguments as to how increased TT length should make a TV/TT combination less stable assuming that the TT length is the only thing that changes.
IMO, we have no clear understanding as to how TT length affects TV/TT yaw stability. However, IMO, it is pretty clear that there are four primary factors which do affect stability. These are:
- Tow Vehicle Weight
- Tow VehicleWheelbase
- Hitch Overhang (distance from TV rear axle to ball coupler)
- TT Weight
- Tongue Weight Percentage
The "guideline" attributed to RV.ORG ignores four of these five factors. My guess is that the "data" which were used to formulate the "guideline" might have contained some correlation between TV weight (which might be correlated to TV wheelbase) and TT weight (which might be correlated to TT length).
One could then take an "average" wheelbase for a range of TV weights and take an "average" length for a range of TT weights and come up with a wheelbase-length relationship for "safe" and "unsafe" TV/TT combinations. However, correlations that might have been appropriate for TV/TT combinations which existed in the 1950/60s (or whenever the unknown data were collected) might not be appropriate for combinations in use today.
IMO, staying within all the TV manufacturer's weight ratings is the primary consideration. If you do that, then the TT length probably will be acceptable also.
Perhaps someday we'll have a "guideline" which properly accounts for all of the primary factors.
Ron
Aug-27-2014 06:14 AM
myredracer wrote:According to this ROT (rule of thumb), Suburbans (including 3/4 ton Suburbans) should not be used to tow trailers which are longer than 25'.
The rule of thumb below to minimize sway has been around for a number of years (from David's RV Tips). I've seen it elsewhere too. Doesn't seem to come up much. If the Armada wheelbase is 123", the max. TT would be 23', well under what the TT appears to be.
The First Guideline
(This guideline was first used by the RV Consumers Group rv.org)
For the first 110" of wheelbase, this allows you 20' of trailer.
For each additional 4" of wheelbase, this gets you 1' more of trailer.
Wheelbase / Trailer length
110" = 20'
114" = 21'
118" = 22'
and so on
Aug-26-2014 08:59 PM
Aug-26-2014 07:13 PM
Aug-26-2014 05:03 PM
Aug-26-2014 12:01 PM
Aug-26-2014 08:17 AM
Aug-25-2014 07:36 PM
Aug-25-2014 06:53 AM
thomasmnile wrote:dspencer wrote:
I have to go now and buy a Freightliner to pull my 26ft Bunkhouse. :R
Are you sure that will be enough truck...........;)
Aug-24-2014 10:40 PM
Ron Gratz wrote:E&J push'n wind wrote:I think we should not imply that "hddecker" was seeing things.opnspaces wrote:I tow with a Hensley too, yeah.., I did catch that but let it go. No, it is not possible unless something is bending or the shear bolts have let go in which case you'll have a mess on your hands. I'd like to hear how that is possible.hddecker wrote:Did anybody catch this post by hddecker? Not picking on you at all hd, just caught the part that your Hensley let the trailer get out of shape. I thought that supposedly wasn't possible?
I let up on the throttle a bit next thing I see in the mirror, backend of the trailer about three feet to the left of center.
Trucks going straight, a little tap to the brake controller switch and the trailer gets back where it belongs.
Sure was happy I had the Hensley Hitch that day.
It's entirely possible -- especially in a low traction condition as might have happened if you're driving in Canada at Christmas time.
It the trailer tires lose their ability to generate lateral force, there is nothing to prevent the trailer from swinging to the side -- makes no difference whether towing with a HA/PP hitch or a conventional hitch.
When "hddecker" let up on the throttle, the 4-bar linkage might have produced a "bump" event which resulted in the trailer swinging to the side.
Even with no "bump", the trailer still can swing if the tire/pavement friction cannot generate sufficient lateral force.
Ron
Aug-24-2014 10:32 PM
opnspaces wrote:hddecker wrote:
I let up on the throttle a bit next thing I see in the mirror, backend of the trailer about three feet to the left of center.
Trucks going straight, a little tap to the brake controller switch and the trailer gets back where it belongs.
Sure was happy I had the Hensley Hitch that day.
Did anybody catch this post by hddecker? Not picking on you at all hd, just caught the part that your Hensley let the trailer get out of shape. I thought that supposedly wasn't possible?
Aug-24-2014 09:59 PM
Aug-24-2014 06:12 PM
Aug-24-2014 05:57 PM