Preventing tractor back flip

[retiredmgn]

I was having a discussion with a friend.
Situation - a chain is attached from the bottom drawbar (several inches below the center of rotation) to an immovable object.
My contention is the front wheels are being driven into the ground. Hence, no wheelie. He says it will still wheelie the same as having the pull point several inches above the center of rotation.
Pull above the center of rotation is a no-brainer -you're going over.
Who's right?

 

[beppington]

It will still flip over

It will just be more of a sling-shot flipover

You're right, initially the front wheels will be driven into the ground, but then given enough rear wheel traction, something has to give. That something is the front end switching from being jammed into the ground to being sling shot (slung shot?) upward, & over.

 

[hosspuller]

As long as the attachment is below the "center of rotation" as you said... no wheelie !

The only way I can think to produce a wheelie is slack in the chain and popping the clutch. Then torque is greater than tractor's inertia and it rotates.... until the chain pulls the tractor back down

 

[hosspuller]

Prove it to yourself and buddy.

Draw a tractor on paper... graph the forces acting on the wheel and tractor drawbar.

 

[beppington]

I thought I could find a video example of an actual flip, but can't so far. However, check this tractor pull video out; Note that the tractor is pulling a wheelie the whole time. Certainly they pull from below the center of rotation, yet still get the front wheels off the ground: ‪NTPA Tractor Pull - Jefferson City, MO‬‏ - YouTube

 

[massey990]

Preventing tractor back flip

I have seen roller guides welded at strategic locations under tractors that allow the operator to pull from the front with the cable/chain/strap connected to the drawbar and run to the front of the tractor, so they pull using reverse.

 

[retiredmgn]

It will still flip over

It will just be more of a sling-shot flipover

You're right, initially the front wheels will be driven into the ground, but then given enough rear wheel traction, something has to give. That something is the front end switching from being jammed into the ground to being sling shot (slung shot?) upward, & over.

I can't get a visual of this in my head. Logically it just don't work.

 

[retiredmgn]

Prove it to yourself and buddy.

Draw a tractor on paper... graph the forces acting on the wheel and tractor drawbar.

That's what I did to try to convince him I was right. Draw a circle with a dot in the middle. An arrow on the circumference showing counter clockwise rotation. A line from below the dot heading right.
Seems obvious to me but he is a stubborn old coot and refused my logic.

 

[jonyyuma]

Logic or not, Try pulling hard..

 

[retiredmgn]

Logic or not, Try pulling hard..

Ok, only if I can use your tractor.