Does the weight of the FEL give you more stability??

[PhilY]

I'm sorry guys but it looks like I can't convince you that the front tires do have equal force on them. Just put it to practice to verify what I have said. If the front axle can pivot while you are driving on a sidehill, then they are both experiencing equal forces. If it can pivot, the force must be "equal and opposite" on both wheels. In regards to stability, I also stand by claim that if the weight from the FEL COG is below the tractor's COG, then it can only help side roll. In regards to the rear sliding out. Depending on the weight of the FEL compared to your tractor the lightening of the rear end may have more of an affect for some then others, but I have not said that the rear end would not be lightened. Good luck!

 

[RaydaKub]

I'll try again. If you could put 100% of the weight on the rear wheels, the COG is going to be in between the rear wheels, certainly inside the tipping point of the outside rear wheel. As stable as you can get. If you could put 100% of the weight on the front wheels (or even a single front wheel), the COG is going to be downhill from the tipping point (that single wheel or the axle pivot). You can raise or lower the COG somewhat, but you can't shift it higher up the hill to balance the tractor. It is going to be on the downhill side of the tipping point. Period. If you tip far enough, then the tipping point becomes the outside of the downhill front wheel, just like on the rear, but you've probably already bailed off or tried to check your seatbelt. This is going to be true no matter if you have a FEL on it or not.

If you add the FEL to it, you will remove weight from the rear and put it on the front. You can add rear weights to compensate for this shift, but that goes beyond the scope of the question the OP asked. This isn't just about the COG or how much it weighs. It is about the COG in relation to the hinge point and the bracing against that hinge that you can manage. On the rear, you've got most of the tractor, but on the front, you've given away 1/2 the width automatically and the COG now is going to pull you over.

As I said several appends ago, the only way this gives you more stability is if you can lower the entire COG, not just the FEL, but of the whole tractor vertically below the pivot point. I haven't ever seen a tractor for which this is going to be true.

 

[PhilY]

Axlehub, just thought I would address your point. When you put the FEL on. It is put on equally on both sides of the tractor. If the arms are attached at an equal distance outward on each side of the tractor, then FEL cannot cause the COG to shift to one side or another. In your example adding shingles in the back of a truck does make the front light. This is analogous to what I said about adding the FEL to the front and how this makes the rear lighter, but only applies front to back not side to side . To use your example in relation to the side to side force, since 2 arms are added, it would be like adding shingles in equal amounts on the front and rear of the truck. So my point simply is that adding the FEL does not shift the COG to a side and if the carrying the FEL close to the ground lowers the tractors COG, and then it is more stable. ie. Corvette vs minivan. As for any object the COG will remain in the exact same position no matter which position it is in. ie. a cube has its COG dead center. If you tip it up one edge the COG appears to move horizontally closer to the edge that is supporting it, but the COG has not moved at all. If you add equal weight to opposite sides of the cube, the COG won't change because the weight on the low side is balanced out by the weight on the high side.

 

[RaydaKub]

I'm sorry guys but it looks like I can't convince you that the front tires do have equal force on them. Just put it to practice to verify what I have said. If the front axle can pivot while you are driving on a sidehill, then they are both experiencing equal forces. If it can pivot, the force must be "equal and opposite" on both wheels. In regards to stability, I also stand by claim that if the weight from the FEL COG is below the tractor's COG, then it can only help side roll. In regards to the rear sliding out. Depending on the weight of the FEL compared to your tractor the lightening of the rear end may have more of an affect for some then others, but I have not said that the rear end would not be lightened. Good luck!

I didn't argue that they had different force on them. But since it is a pivot point, that part doesn't matter. The point is, since this IS a pivot, it exerts NO force to prevent you from tipping over. The weight is immaterial. The COG is downhill from the pivot (until the stop is hit) and it will not prevent a roll over, in fact it helps the roll along. The rear end has the pivot point downhill from the COG and thus the COG helps you maintain clean shorts.

As I hinted at above, until the stop is hit, your front end may as well be a single wheel in terms of tipping. It cannot add any stability at all up to that point, so it would be foolish to rely on it doing so. And that's why transferring any weight to the front is not going to help. You can compensate (and you should), but you can't defeat the laws of physics.

Sliding out is a whole 'nother issue.

 

[PhilY]

the only way this gives you more stability is if you can lower the entire COG, not just the FEL, but of the whole tractor vertically below the pivot point. I haven't ever seen a tractor for which this is going to be true.

I agree with this completely and is what I have been saying. If the FEL is carried low enough it can shift the COG down. While this may be only 1/8" it is down rather than up. So per the point of the OP, it is more stable even if it is only by 0.1%.

You can raise or lower the COG somewhat, but you can't shift it higher up the hill to balance the tractor.

And as you said here, if you can't shift it uphill, you can't shift it down hill either.

 

[PhilY]

I didn't argue that they had different force on them. But since it is a pivot point, that part doesn't matter. The point is, since this IS a pivot, it exerts NO force to prevent you from tipping over. The weight is immaterial. The COG is downhill from the pivot (until the stop is hit) and it will not prevent a roll over, in fact it helps the roll along. The rear end has the pivot point downhill from the COG and thus the COG helps you maintain clean shorts.

As I hinted at above, until the stop is hit, your front end may as well be a single wheel in terms of tipping. It cannot add any stability at all up to that point, so it would be foolish to rely on it doing so. And that's why transferring any weight to the front is not going to help. You can compensate (and you should), but you can't defeat the laws of physics.

Sliding out is a whole 'nother issue.

Raydakub, I agree with what you have said that only the rear keeps you from rolling over as this is what I have been trying to say per post #22. Our tractors are like those old 3 wheelers with our front rocking axle. I understand that you weren't arguing the point that they had different forces on the front wheel, just wanted to make sure we all knew the physics of these things with how many people got hurt and I am sure no one can say that we all didn't put a lot of thought into this topic today!

 

[JoeBuyer]

I have two MF245s, one with a loader and one without a loader. The one without is much more stable.

 

[RaydaKub]

I agree with this completely and is what I have been saying. If the FEL is carried low enough it can shift the COG down. While this may be only 1/8" it is down rather than up. So per the point of the OP, it is more stable even if it is only by 0.1%.

And as you said here, if you can't shift it uphill, you can't shift it down hill either.

You don't shift the COG downhill, but you shifted the pivot point from the outside to the middle. Again, assume a hillside with uphill being on your right and you are looking at the tractor from the rear. The COG exerts a clockwise force on the outside of the left rear wheel. When you move the weight forward, the COG now exerts a force counterclockwise on the pivot point because the pivot moved to the middle of the tractor while the COG moved slightly to the left. And your front axle has no force to counter act this shift.

In an earlier post, you said you didn't think it would shift all that much weight. I don't recall the exact numbers, but I think my BX weighs 1200-1300lbs dry. The FEL adds 400lbs. A fair amount of that is up high, not good. But the weight shift forward is very significant. The COG may be lower by 0.1%. But it also moves the COG forward a long ways. You've already lost at least 10% because of where the force is exerted and from the pucker factor I've experienced, I'd guess it is a lot closer to 40%.

If your FEL is capable of lowering the COG at all, then I will assert that it also moves a heck of a lot of weight forward because it must be very heavy.

 

[Egon]

A force vector diagram might be interesting.

 

[RaydaKub]

I'm at work now and I'm certainly no artist, but I'll attempt to draw up something later.