Buying Advice Ballast Box vs Wheel Weights vs Filled Tires

[rjkobbeman]

Out of idle curiosity, since a tractor has no suspension, wouldn't the issue of sprung/unsprung weight be a moot point in dealing with weight distribution and stability?

Yes, that is what I was trying to say... then people took it personally. Earlier I said the whole tractor is unsprung weight.

 

[ovrszd]

Yes, that is what I was trying to say... then people took it personally. Earlier I said the whole tractor is unsprung weight.

This has gotten so petty. Technically correct. But petty.

So for the technical gurus, answer these two questions.

1. Describe the difference of weight added to the tractor on the tire/wheel combination versus weight added to the tractor on the chassis and it's effects on the tractor.

2. What do you call weight added to the tire/wheel combination if you can't accept calling it unsprung weight.


End result, the most effective weight is the weight added to the tire/wheel combination. Least effective weight is weight added to the 3pt.

My reasoning is the tire/wheel weight added is applying downward pressure at the most effective spot, the contact patch of the tire and the ground. The least effective is weight added anywhere else on the chassis because under certain conditions that weight can actually make the tractor more unstable. An example would be 500lbs of weight hanging on the 3pt in an extremely uphill situation with no load on the FEL. Or a 500lb brush cutter swinging on the 3pt in an extremely side slope situation with no load on the FEL.

In TripleR's case with his tractor that requires ballast beyond tire/wheel weight he has no choice but add 3pt ballast. I'm sure if the tractor would work without that weight he wouldn't add it. I'm also sure under certain circumstances that 3pt ballast becomes a hinderance rather than an aid. I'm fortunate that my tractor seems to handl the FEL rather well with only fluid in the rears.

So there ya go rjk, I gave you plenty to pick apart in this one.

 

[RoadHogg]

This has gotten so petty. Technically correct. But petty.

So for the technical gurus, answer these two questions.

1. Describe the difference of weight added to the tractor on the tire/wheel combination versus weight added to the tractor on the chassis and it's effects on the tractor.

2. What do you call weight added to the tire/wheel combination if you can't accept calling it unsprung weight.


End result, the most effective weight is the weight added to the tire/wheel combination. Least effective weight is weight added to the 3pt.

My reasoning is the tire/wheel weight added is applying downward pressure at the most effective spot, the contact patch of the tire and the ground. The least effective is weight added anywhere else on the chassis because under certain conditions that weight can actually make the tractor more unstable. An example would be 500lbs of weight hanging on the 3pt in an extremely uphill situation with no load on the FEL. Or a 500lb brush cutter swinging on the 3pt in an extremely side slope situation with no load on the FEL.

In TripleR's case with his tractor that requires ballast beyond tire/wheel weight he has no choice but add 3pt ballast. I'm sure if the tractor would work without that weight he wouldn't add it. I'm also sure under certain circumstances that 3pt ballast becomes a hinderance rather than an aid. I'm fortunate that my tractor seems to handl the FEL rather well with only fluid in the rears.

So there ya go rjk, I gave you plenty to pick apart in this one.

Ah! So this explains why I loose my balance so easily, most of my weight is sprung weight!

 

[ovrszd]

Out of idle curiosity, since a tractor has no suspension, wouldn't the issue of sprung/unsprung weight be a moot point in dealing with weight distribution and stability?

TripleR

I touched on this in my reply to rjk. But I'd like to reinforce the issue with you. You use 3pt ballast on one of your tractors because the weighted rears aren't enough ballast. Wouldn't you agree that during all aspects of operation the most effective added weight is the tire/wheel weight?? The less effective weight being the 3pt weight?? If you agree with this then you must agree that weight added to the tractor chassis in any manner other than tire/wheel weight is definitely a point because of it's inherint lack of effeciency in dealing with weight distribution and stability.

 

[ovrszd]

Ah! So this explains why I loose my balance so easily, most of my weight is sprung weight!

Exactly!!! And our center of gravity has most certainly shifted!!! :laughing:

 

[TripleR]

TripleR

I touched on this in my reply to rjk. But I'd like to reinforce the issue with you. You use 3pt ballast on one of your tractors because the weighted rears aren't enough ballast. Wouldn't you agree that during all aspects of operation the most effective added weight is the tire/wheel weight?? The less effective weight being the 3pt weight?? If you agree with this then you must agree that weight added to the tractor chassis in any manner other than tire/wheel weight is definitely a point because of it's inherint lack of effeciency in dealing with weight distribution and stability.

I don't have the technical expertise some if not most on here, so this is probably all over my head.

Like raising children, I am not sure there is an "always/never" answer to the question. I operate tractors on flat ground and hills and what works great going up hills with a load may not work so well backing out with a load. Weight hanging on a 3-point compromises stability going up or across hills which was aptly demonstrated when we went from a 3-point Woods 121 10' to a pull behind Woods DS1260. Even though the DS1260 is heavier, it affects the tractor far less as it attaches to the draw bar and is never raised. The 121 hanging from the three point tended to move the tractor around quite a bit more even when lowered.

On flat ground, the difference really is almost negligible.

My belief is that from a pure stability standpoint overall that weight in and on the wheels is preferable to weight on the three point. I can, however see why some prefer the ability to run lighter for some tasks and add weight when needed. If you have sufficient weight in and on your tires to handle loads in/on your FEL, you will be hauling that weight around all of the time and paying for fuel to do so as well as possibly having to add front weights when you remove your FEL. Whether this is worth it is up to the individual's needs.

From having owned and driven several different tractors, wheel base as well as weight play a part in the need for "counter balance".

We used our CX80 for 12 years and did not use any weight on the three point and still use an old 86 MF375 and never need anything on the three point. We use these tractors to pull all sorts of stuff including a 10' no till drill, so filled tires are a must and tailoring weight distribution was never an issue. Our renters use a John Deere 7000 Series with dual rear tires for FEl and mowing etc; never saw anything on the three point.

I own a tractor like rjkobbeman as well as L5030 HSTC and even with loaded tires, doing loader work without something on the three point is

Even though wheel weights would probably provide the needed stability, I don't want to haul all that weight around all the time on my L5030, so I put something on the three point.

On the M8540, I wanted the cast wheel disks as well as loaded tires, but couldn't wait the four to six weeks to get them. We are still in the learning curve on this tractor and until we get a real handle on it, we are going to make a ballast box and decide on wheel weights down the road.

I don't know if that made any sense.

 

[Recoveryhill]

Calling it Sprung/Unsprung weight uses the reference to a "spring" as a convenient dividing line between the kit above the axle and the wheel/tire combo as most all rolling stock has springs and it is a convenient way to refer to things, an arbitrary dividing line, that's all.

Springs are a device installed on rolling stock ever since the days of horse and carriage and are there for one reason and one reason only; they make the ride easier on the rear end of the passenger.

Their presence or absence has no bearing on the physics of a single, dual, three, four or eighteen plus wheeled vehicle. Tires and wheels are unspung weight and all that lies above the axle is sprung weight, whether it bounces or jars the rear end of the operator. Springs or lack thereof also have no relation to roll-over, except in the case of soft springs and excessive body roll which shifts the CG to the "downhill" side and makes a roll over more likely. Tractors, with no springs see no shift in CG, it stays put along the vertical axis to the ground but that weight is still sprung, even though it is fixed with relation to the axle.

I threw in the 3pt weight as a fifth wheel because it looked right but I'm willing to agree that it may not be unsprung if any of its weight is carried by the structure above the axle, which it is. It does lower CG, but that does not make it unsprung.

This is my last post on the subject, believe what you care to believe. There is a vast body of knowledge on the subject used by vehicle manufacturers and modifiers. Some applications attempt to reduce unsprung weight and others find an increase a benefit. In tractors, increased unsprung weight is a definite benefit and high CG sprung weight a definite liability.

 

[TripleR]

Calling it Sprung/Unsprung weight uses the reference to a "spring" as a convenient dividing line between the kit above the axle and the wheel/tire combo as most all rolling stock has springs and it is a convenient way to refer to things, an arbitrary dividing line, that's all.

Springs are a device installed on rolling stock ever since the days of horse and carriage and are there for one reason and one reason only; they make the ride easier on the rear end of the passenger.

Their presence or absence has no bearing on the physics of a single, dual, three, four or eighteen plus wheeled vehicle. Tires and wheels are unspung weight and all that lies above the axle is sprung weight, whether it bounces or jars the rear end of the operator. Springs or lack thereof also have no relation to roll-over, except in the case of soft springs and excessive body roll which shifts the CG to the "downhill" side and makes a roll over more likely. Tractors, with no springs see no shift in CG, it stays put along the vertical axis to the ground but that weight is still sprung, even though it is fixed with relation to the axle.

I threw in the 3pt weight as a fifth wheel because it looked right but I'm willing to agree that it may not be unsprung if any of its weight is carried by the structure above the axle, which it is. It does lower CG, but that does not make it unsprung.

This is my last post on the subject, believe what you care to believe. There is a vast body of knowledge on the subject used by vehicle manufacturers and modifiers. Some applications attempt to reduce unsprung weight and others find an increase a benefit. In tractors, increased unsprung weight is a definite benefit and high CG sprung weight a definite liability.

Interesting post, thanks.

 

[ovrszd]

Triple R,

Several years ago, maybe as much as twenty years ago for some manufacturers, tractors started being made with shorter wheelbase. I noticed this trend coming when in Europe in the early 80s, their tractors already were very short compared to ours. When I started seeing that design here I called it European. Not sure what the Manufacturers labeled it. Now almost all tractors are built in that fashion. Creates the situations you talk about with a couple of your tractors. The FEL lift capacity far exceeds the counter balance weight offered by such a short wheelbase. This creates that necessity of 3pt ballast. As you said, it's simply not efficient to add enough weight at the wheels to counteract that and have to haul that weight around every day.

I also agree with you that 3pt ballast has little negative effect on flat ground.

Also agree with Recovery in his descriptions, right on the mark.

 

[crazyal]

Just to get people going a little we should talk about center of gravity. With wheel weights and filled tires the center of gravity could be higher than with a ballast box. Wheel weights the center of grav is the axle. With filled tires it's a little below the axle (since the fluid doesn't go to the top of the tire). With a ballast box, depending on shape and how high it's raised could be lower than the other two. Just thought I would throw that out there because this thread hasn't gone on long enough, lol.