OK guys today was weight day to determine necessity for rear counterbalance

[JCByrd24]

I'm guessing some of you guys also recognize the benefits of not running in 4wd all the time. Seems I was one of the first to post that this was not a good idea in the thread "Full time 4wd"...you guys need to go over there and back me up.

I think it takes running a smaller tractor without power steering to really appreciate the benefits of rear counterweight. A tractor that'll lift the rear tires goes a long way as well. I'm guessing a lot of big tractors won't do this, with longer wheelbases and more weight out back, but the principles are the same and the front axle is always lighter and more complicated than the rear.

 

[Bluegill2]

I'm guessing some of you guys also recognize the benefits of not running in 4wd all the time. Seems I was one of the first to post that this was not a good idea in the thread "Full time 4wd"...you guys need to go over there and back me up.

I think it takes running a smaller tractor without power steering to really appreciate the benefits of rear counterweight. A tractor that'll lift the rear tires goes a long way as well. I'm guessing a lot of big tractors won't do this, with longer wheelbases and more weight out back, but the principles are the same and the front axle is always lighter and more complicated than the rear.

Absolutely. I only use 4wd when needed!

 

[Tx Jim]

I guess I'm dumber on physics than I thought. It still appears to me if I have a 1100+ rd bale on the FEL that the frt axle will be a fulcrum point if frt axle only is weighed. How about Y'aLL donate to a windshield wiper fluid fund then I'll install the fluid then I'll take tractor/loader/hay for a re-weigh.:cool2:

 

[k0ua]

I guess I'm dumber on physics than I thought. It still appears to me if I have a 1100+ rd bale on the FEL that the frt axle will be a fulcrum point if frt axle only is weighed.

Well I don't disagree with anything you just said here, but if you put 1 million pounds of wheel weights on the wheels or 1 million pounds of fluid in your tires, it wont take a single pound off of the front axle. The only way you are going to remove pressure on those front tires by adding weights is to put weight on the 3pt. hitch, as that weight is behind the rear axle, and will act as a lever arm to pry up the front of the tractor. If you put enough weight on the 3pt hitch you will pry the entire front end off of the ground. When you put 870 lbs on the 3pt, your removed 610 lbs of pressure from the front. But putting fluid in the tires, while a great idea, will NOT relieve pressure on your front axle or front tires. I think this is what we are debating at this time. Correct me if I a wrong.

James K0UA

 

[sdkubota]

I guess I'm dumber on physics than I thought. It still appears to me if I have a 1100+ rd bale on the FEL that the frt axle will be a fulcrum point if frt axle only is weighed. How about Y'aLL donate to a windshield wiper fluid fund then I'll install the fluid then I'll take tractor/loader/hay for a re-weigh.:cool2:

The loader doesn't rest on the front axle but rather the main supports that come down between the axle. The primary loads transferred at those points are vertical and a large moment which is what places the additional loads on the front axle. These loads may or may not represent the entire weight in the front bucket. You are correct the front axle is greatly affected by what you are lifting.

 

[RaydaKub]

I guess I'm dumber on physics than I thought. It still appears to me if I have a 1100+ rd bale on the FEL that the frt axle will be a fulcrum point if frt axle only is weighed. How about Y'aLL donate to a windshield wiper fluid fund then I'll install the fluid then I'll take tractor/loader/hay for a re-weigh.:cool2:

It remains the fulcrum right up to the point where the rear end becomes the fulcrum. It has nothing to do with which axle is being weighed. By that logic, you would only have a fulcrum while the tractor is being weighed. Once you drive off scale you no longer have a fulcrum? Doesn't work that way.
You continue to have 2 lever arms at work here. The front bale is on an arm balancing across the front axle. You hope the rear end is heavier so it stays on the ground. If that part is accomplished, then the second lever arm comes into play and is whatever is behind the rear axle. Once again, you hope that the front end is heavy enough that you aren't doing a wheelie. Hard to think of a tractor doing a wheelie with a 1000 lb bale on the fel, but in theory it could happen.

 

[k0ua]

What I have not addressed with my "absurd" weight scenario's is that the integrity of the tractor engine bell housing, transmission etc. have a finite amount of strength. At some point something is going to break.....crunch....

 

[FTG-05]

Load the rears and widen the stance some...View attachment 335293View attachment 335294

How do you widen the stance and I *assume* you're talking about the rears only?

Thanks,

 

[k0ua]

How do you widen the stance and I *assume* you're talking about the rears only?

Thanks,

Many wheels are adjustable so that you can change the "dish" of the wheel so that the track can be widened. I bet yours are adjustable. Look in your manual. Mine are not adjustable, and the only way to widen the stance would be to add wheel spacers.

James K0UA

 

[LD1]

There are two fulcrum points at play. The front axle and the rear. Which fulcrum you use in your calculations depends on what you are trying to find out.

The load of hay on the FEL spear is using the front axle as a fulcrum. All that weight hanging forward of the front axle is like a big lever trying to lift everything behind it.

A load on the 3PH bale spear uses the rear axle as the fulcrum, and tries to unload everything forward of that, as you demonstrated.

But all the weight in the world directly over the fulcrum does nothing fore and aft of the fulcrum. If the goal is to lighten everything forward of the rear axle (like the front axle), the weight HAS to be behind the fulcrum (rear axle).

Picture this simple lever. Like a teeter totter. The fulcrum (middle of the teeter totter) is the rear axle. The goal is to reduce weight on one side of the teeter totter. You can put 100lbs or 1000lbs directly over the pivot (rear axle) and it wont effect the weight on either side right??? The only way to effect one side is to add weight to the other. So adding 1000lbs of liquid tire ballast will only add 1000lbs to the rear and nothing else.

No need to load the tires to test. If you want to make a trip back to the scales, you dont even need any hay. Just take a couple of hefty buddies. When sitting with the front axle only on the scales, make note of the weight. Now have them buddies stand on the tires right in the middle and see that there is no change of front axle loading.

Now a bit sideracked, I mentioned in the L3400 thread, that up to a point, adding weight, even behind the rear axle, "can" add more weight to the front axle. Lets use your 7700# tractor as an example. Lets say you can only lift 1500# before the rear tires leave the ground. Now your front axle is carrying the entire 7700+1500lbs. Thats 9200lbs. Now you add a 600lb rear blade. And now you can lift 2000lbs up front but can still raise the rear tires. So now the entire 7700 tractor + 2000lb load + 600lb blade are ALL on the front axle. Thats 10,300lbs now.

The the key is to use enough ballast that the rear axle REMAINS the fulcrum point, cause when its in the air, it isnt the fulcrum. And all the weight you added in the tires OR behind it, is now all on the front axle.

Clear as mud right:thumbsup: