Been having a constant problem with my trailers wandering all over the road this trip. At first I put it down to the strong winds we have experienced in the last couple of days. Then I was checking all my tyres with a pressure gauge (after I used a gimpie on them – see previous post) and I even put some extra grease on the fixed turntables. Nothing helped.
Then I realised all three trailers where traveling nose high and tail low. Now, I got to say that each trip I will have different trailers and different dollies and that slowly creeping (down) ride height adjustments on the fleet of trailers doesn’t seem to feature on the workshops “tick n flick”.
So, based on previous experience with saggy arsed trailers, I crawled under each in turn and adjusted the airbag ride height valve until they where sitting as close to level as I could make them by eye. And it worked.
Instead of shambling down the road looking like a train wreck that was at the “waiting for the dust to settle” stage of a truly spectacular event, they now tag along obediently and I’m not getting the cramps in my hands you get when nothing you do with the steering wheel up front can possibly explain why you can read ALL of the signwriting on the sides of all three trailers, first in one mirror – then in the other.
Leveling up the trailers didn’t just affect each individual trailers handling, it also had two separate flow-on effects on Dolly No.1 and to a greater degree on Dolly No.2 due to the “whip like” effect generated during the white knuckle moments.
How To Create Your Own White Knuckle Experience.
You will need :
3 x Saggy Arse Trailers
2 x Old Single Point Dollies (A-Frames must be high and slope down towards Saggy Arse Ringfeder when engaged)
Quote : “Remember : Trailers are long, dollies are the short ones.”
(Wise old transport manager)
Note : The values assigned to the measurement of Inches and Degrees are intended only to indicate greater and lesser values-they are not true values.
If the rear of a trailer sways 6 inches out of line with the front of that trailer and the direction of travel it might be, say, 3 degrees off that “straight down the middle” path of least resistance or drag. Now the dolly, being attached to the trailer, is also dragged out of line but it is at , say, 6 degrees out of line because it has to turn sharper to move over 6 inches due to it’s drastically shorter length. Ok, generally speaking, when objects like these move out of line they will quite often move back toward that center line and even swing out the other side of that line like a pendulum. If this doesn’t happen then you will more than likely be able to see in your mirror an impressive cloud of dust rising into the air and a lot of stuff getting very bent and twisted. Now don’t forget that something out of line by 6 deg is going to have a more violent return swing than the trailer that was only a little out at 3 deg.
Also, we have to start looking at the 2nd trailer which is hooked up to the dolly and has just been shoved further than 6 inches out of line due to the more aggressive turns the dolly was forced through and the higher inertia forces. Let’s say the dolly and 2nd trailer were forced 8 inches out of line at the furtherest point our of line on the first swing away.
What does this mean :
A) the angle the 2nd trailer will be at?
B) the distance the rear of the 2nd trailer will be from the center line?
C) the angle the 2nd dolly will have to turn at to follow the rear of the 2nd trailer and the effects of inertia on this equipment at this step in the process?
D) the 3rd trailer, hooked to the 2nd dolly, will be doing what?
Answers :
A) the 2nd trailer will be at a greater angle due to being forced further out of line than the 1st trailer but at a lesser angle than the 1st dolly because of it’s greater length. Let’s say 4 deg.
B) the greater angle of the 2nd trailer means more inertia but it’s length should still enable it to be less than or equal to the the 1st dolly and the front of the 2nd trailer. =< 8 inches.
C) the angle of the 2nd dolly will be 8 deg to keep up with the increased angle of the 2nd trailer over the 1st trailer. Inertia increasing forcing 2nd dolly and front of 3rd trailer out to 9 inches.
D) the 3rd trailer will be going bloody spastic! It's the cracker at the end of the whip – swing it hard enough and all that velocity and inertia will do something loud or bad or both.
Quote : "Always have an excuse ready. If possible, have more than one"
(From a screwup I used to know)
Dude, I have no idea which deep, dark recesses of my mind I pulled that from! It started out as a normal post and warped into this.
Mike.