Turning circles

[Belbein]

I'm looking at various options for upgrading our AS situation, and one factor that seems to keep coming up is how tight a turning circle I need to plan on. Does anyone know if this is published anywhere? I know that part of it has to do with the length of the tow vehicle, but it seems like somewhere or other there has to be a formula. (This will tie into the issues of: do we build a circular drive? do we have to cut down a tree next to our driveway? do we have room to move up from a 22 to a 25 or 27...) Appreciate any thoughts.

[SteveSueMac]

I don’t have the math - but I tow a 27’ with an extended cab short bed pickup and a ProPride (which adds some length) and total rig is 50-some feet long. I can turn it around in a cul-de-sac so long as there aren’t cars parked on more than one side of it. Don’t know if that’s helpful to you...

[Mollysdad]

There's too many factors to publish a number. Even the length of your shank plays a part.
However, I've always find I can turn tighter than I think. Let's say I'm exiting a gas station and have to clear a parked car. Before I think about crunching the tank cover, I stop, put the truck in reverse so the back-up camera comes on and look at the available angle.
There have been times....I wanted to make a U-turn on a 4 lane divided highway. I got into the turn lane, started, then realized there was no intersection, just the turnout. Cars were coming so I had to go for it. It didn't hit. Phew!

I think about going to an empty parking lot, and trying circles. Maybe put some cones out. Reverse while watching the back up camera. When it's as close as I'd feel comfortable with, pull forward without changing the steering.

[joshjack]

Without knowing what you’re looking at I would say it’s not been a big deal for us. Between our RAM 2500 MegaCab and the 30’ AS we’re well over 50’ and we haven’t run into any turning issues. I’ve had to back out of some hairy spots before, but I’m not sure a tighter turning radius would have helped unless were talking about a tracked, zero turn radius tow vehicle.

We have a narrow, tree lined, and winding driveway and I just back the AS in from the street to its parking spot next to the garage. Just takes practice.

[LilPeanut]

There is a formula but I believe one of the biggest factors will be the turning radius of your TV alone. Different trucks and cars have different turning abilities. That is the first factor.

The second is the distance between the pivot point and the center line of the axles. This is easier to imagine when you think about tail swing (it is the reverse of tail swing when you picture it). Tail swing, if you are pivoting 45degrees is one half the distance between the rear bumper and the center of the axles plus one quarter of the width of the trailer. If you want to visualize this, think of only your TV and imaginary front wheels turned 90 degrees. The rear would still swing out as the TV pivots on the axles in a circle without moving forward or backwards.

The tighter your TV will turn will determine how tight your turning radius is. That said, the turning radius of the TV transfers to the hitch at the ball. The tighter you turn the TV wheel, the tighter the trailer turn will be. If you turn the TV wheel 10deg and hold it constant, there will be a constant angle at the ball, all determined by the degrees of turn in the TV. I will have to think about it but I believe it is also 10deg but pivoting along a new centerline, which makes it feel like it is ‘inside’ the circle of the TV turn. It is, but it is not turning tighter, it is just a different vehicle with different geometry turning at the same angle.

Ignoring your limitations placed on a turn by the hitch, chains, propane cover (I use a Hensley so I have greater clearance with those, which is the real value of the HAHA), the TV can make a big difference.

[LilPeanut]

Also, think of if you have ever towed a boat. They always have a good turning radius. That is because the wheels on a boat trailer are way at the back, so the boat trailer is following way ‘inside’ the turn of the TV. If the wheel of a trailer were way at the front of a long trailer, they will follow very closely the circumference of the TV but you would trade more tail swing.

On RVs the axles are just behind a mid point. It makes people visualize that the turn is wider but it is not. It is the TV radius plus tail swing (again ignoring hitch limitations). There is almost no tail swing on a boat trailer. But there would be giant tail swing on an imaginary 30’ trailer with axles way at the front.