If this question should be in towing, I apologize. I don't have a feel yet for what the spirit of forum distribution is here.My property has a branch off the main driveway that goes to the barns. Pretty tight area back there for turning around because of topography. For farm equipment, I usually just open a gate and turn around in the pasture so I can get the rig facing out the drive. Since my 5th wheel is going to be stored back there, I need to make provisions for turning it around that don't involve an off-road excursion or cow manure on the tires.I plan to build a loop in the drive which will involve moving fence and adding some gravel. My plan was to just turn the rig around a few times without going 90 degrees to see what a reasonable turn is. Then I'll mark the grass and make a road. I'm planning on a kind of offset teardrop so I can turn slowly at first when I'm near a building, then once the back end of the trailer clears I can turn faster.But what if I get a bigger trailer or different truck? I don't want to do it all over again. Any thoughts on how adding length from pin box to axle would affect "comfortable" turning radius? Or is there a rule of thumb that would guide me? I don't want to go crazy since the further I extend the loop, the deeper the gravel will need to be to keep the road level from side to side.

Can you calculate it - yes; but it would be so difficult that you don't want to. (it would involve turn radius of the truck, distance from wheels to hitch, distance from hitch to axles, etc.)Better to just go to a open parking lot and chalk mark it on the pavement and measure the diameter you need.

troubledwaters wrote:Can you calculate it - yes; but it would be so difficult that you don't want to. (it would involve turn radius of the truck, distance from wheels to hitch, distance from hitch to axles, etc.)Better to just go to a open parking lot and chalk mark it on the pavement and measure the diameter you need.Add to that how acute an angle you can get with the truck and trailer and keep the front cap from hitting the back of the truck (variables: front cap design, position of pin box to front cap, position of hitch in truck bed, itch-to-cab distance, etc.). Every truck/trailer/hitch combo is different. Rob

Build scale models of differing dimensions.

Do a google search for turning templates for trucks. You should be able to find something similar to the length you are working with.

I would say measure from the pinbox to the rear of the trailer plus the width of the truck, but if you have the room add another 10'. I have turned mine past 90 degrees in tight areas.

Turning Radius -- Can it be calculated/estimated?

troubledwaters
Explorer III
Jul 13, 2017
Can you calculate it - yes; but it would be so difficult that you don't want to. (it would involve turn radius of the truck, distance from wheels to hitch, distance from hitch to axles, etc.)
Better to just go to a open parking lot and chalk mark it on the pavement and measure the diameter you need.
Second_Chance
Explorer II
Jul 13, 2017
troubledwaters wrote:
Can you calculate it - yes; but it would be so difficult that you don't want to. (it would involve turn radius of the truck, distance from wheels to hitch, distance from hitch to axles, etc.)
Better to just go to a open parking lot and chalk mark it on the pavement and measure the diameter you need.

Add to that how acute an angle you can get with the truck and trailer and keep the front cap from hitting the back of the truck (variables: front cap design, position of pin box to front cap, position of hitch in truck bed, itch-to-cab distance, etc.). Every truck/trailer/hitch combo is different.

Rob
2oldman
Explorer II
Jul 13, 2017
Build scale models of differing dimensions.
schlep1967
Nomad
Jul 13, 2017
Do a google search for turning templates for trucks. You should be able to find something similar to the length you are working with.
corvettekent
Explorer
Jul 13, 2017
I would say measure from the pinbox to the rear of the trailer plus the width of the truck, but if you have the room add another 10'. I have turned mine past 90 degrees in tight areas.
stickdog
Explorer
Jul 13, 2017
Just hook her up and drive it through the loop you want to make. Then stake out a little wider than the tire marks in the grass. BAM your set. I hate to over think things.
korbe
Explorer
Jul 13, 2017
troubledwaters wrote:
Can you calculate it - yes; but it would be so difficult that you don't want to. (it would involve turn radius of the truck, distance from wheels to hitch, distance from hitch to axles, etc.)
Better to just go to a open parking lot and chalk mark it on the pavement and measure the diameter you need.

I agree, no math needed. Just go to an open parking lot, mark the outside edge of your truck on the ground, start a sharp slow turn, watching the nose of your rig, and once you've done a 180, measure the diameter. whah-lah, done.
IdaD
Explorer
Jul 13, 2017
You can measure distances on Google maps. I used that to figure out the best way to turn around at the back of my property down by my shop. For me it was helpful to have that overhead shot and then figuring out the distances between my outbuildings - for me the choke point was between a shop and storage shed. It is awesome to be able to pull in forward and turn around so I can pull it back out forward also.
laknox
Nomad
Jul 13, 2017
What's wrong with manure on your tires? It's a =truck=! :B

Lyle
CarnationSailor
Nomad
Jul 13, 2017
Going to a parking lot with a piece of chalk is all you need to do. And you can leave the 5th wheel at home. Since the 5th wheel's tires turn inside the arc of the truck's tires, it is the turning radius of the truck that defines the minimum diameter you need.