Preventing tractor back flip

[SPYDERLK]

Cant say Ive seen seen a cogent discussion of fixed drawbar length - altho FMJ and perhaps XTN mentioned it. The drawbar must be somewhat below the rear axle and its end must extend rearward out beyond the circle made by the tires. This will prevent a back tipover in all cases except [perhaps] a running start. Previous discussions:
http://www.tractorbynet.com/forums/safety/189672-what-causes-flip-overs.html

 

[Degolyerent]

Cant say Ive seen seen a cogent discussion of fixed drawbar length - altho FMJ and perhaps XTN mentioned it. The drawbar must be somewhat below the rear axle and its end must extend rearward out beyond the circle made by the tires. This will prevent a back tipover in all cases except [perhaps] a running start. Previous discussions:
http://www.tractorbynet.com/forums/safety/189672-what-causes-flip-overs.html

Not 'all' cases

 

[SPYDERLK]

Not 'all' cases

Please describe a situation that would cause a tractor to tip over backward when pulling from a fixed drawbar fastened below the axle and extending back far enuf that its end, and therefore the pull point, is outside the circle made by the tires.
larry

 

[JoeL4330]

Please describe a situation that would cause a tractor to tip over backward when pulling from a fixed drawbar fastened below the axle and extending back far enuf that its end, and therefore the pull point, is outside the circle made by the tires.
larry

is your point that the fixed draw bar becomes a "wheelie bar" ? ....and won't let the tractor complete the backflip?

 

[Don87]

Please describe a situation that would cause a tractor to tip over backward when pulling from a fixed drawbar fastened below the axle and extending back far enuf that its end, and therefore the pull point, is outside the circle made by the tires.
larry

Not trying to be argumentative or anything, just trying to provide info to tractor users.

But with that said, if the drawbar is attached to the tractor, isn't that the real hitch point?
I understand that the drawbar can be made 3 feet long, and below the axle, but the main problem seems to be that the tractor can gain traction, thus spinning the rear wheels on their axis............causing a flipover.
The only thing I can see is that a long drawbar..........may act as a 'wheelie bar' of sorts, and could prevent a backwards flip, but could in turn cause a sideways flip when the drawbar hits the ground............couldn't it?

 

[k0ua]

This is interesting, pulling a near immovable object from a standing start. instead of the usual easy to start, but hard to keep going type of tractor pull.


Tractor pull with David Allan Coe soundtrack - YouTube

James K0UA

 

[Degolyerent]

Well you said ' all' cases, but what if the tractor were on runners with no ground under it or even very soft ground, my point is never say' all' cases

 

[xtn]

Seems to me that any normally found drawbar length would stab in the ground and not act as a wheelie bar at all.

xtn

 

[Reg]

Maybe we should put it this way: Until there is absolute certain proof that there is some way to connect a to-be-pulled object to your tractor such that it can not flip over backwards ... everybody should assume it can happen :thumbsup:

...and THAT way is to ensure that the geometry is "right"

There needs to BE a draw bar.
It needs to be long enough to just about reach the ground before the tractor (with driver, ballast, etc) center of mass gets close to vertically above the rear axle center line.
I am NOT saying that it needs to serve the purpose of a wheelie bar, it just needs to ensure that a stable equilibrium is reached.

Idiots doing Garden tractor flips on You tube aside.
That shouldn't have passed entry inspection.
Gee, I wonder if there even was a safety inspection.

 

[Don87]

...and THAT way is to ensure that the geometry is "right"

There needs to BE a draw bar.
It needs to be long enough to just about reach the ground before the tractor (with driver, ballast, etc) center of mass gets close to vertically above the rear axle center line.
I am NOT saying that it needs to serve the purpose of a wheelie bar, it just needs to ensure that a stable equilibrium is reached.

Idiots doing Garden tractor flips on You tube aside.
That shouldn't have passed entry inspection.
Gee, I wonder if there even was a safety inspection.

The first link I posted was a tractor pulling contest.

Tractor pull gone wrong - YouTube

The second link was in fact 'idiots' that probably said "hold my beer and watch this".

The third link was also a tractor pulling contest. 100_0010.MOV - YouTube