I'm modifying a lawn tractor to pull single axle trailers in a woodland environment. They are rear wheel drive, have enough power, but traction is our biggest issue even when using tractor/ATV tyres.
My question is - what height (in relation to the rear axle) should the tow hitch be at and why?
I have looked at tractor pulling for comparisons and
they seem to go as high as they can within the rules but I understand this is due to benefits of lifting the front of the sled off the ground.
they extend the hitch to influence front wheel lift - I guess this is to put more weight on the back axle.
Front wheels lifting on woodland slopes isn't ideal so I have always opted to go low (below axle line) as this pulls the front down and I don't see how it could reduce the weight on the back wheels.
But a physics explanation would be really helpful.
EDIT: I also found these two links which undertake a complex analysis of sled pulling with trucks under the title 'Physics of a truck pull, using a 2WD pickup truck'.
- Part I - A simplified physical model captured by a single equation
- Part II - Enhancements to the dynamics of the simplified model