Weight distribution

bebster · Apr 6, 2004

One trick I've used recently when the FEL is a little full and heavy, is to extend the backhoe a little farther back. This helps shift the center of gravity to the rear and provide some temporary stability for that extra heavy load from time to time.

KiotiJohn · Apr 7, 2004

This is a quote from Firestone Tire Company on liquid ballasting of tubeless tires:

Step 2: Check for Proper Weight Distribution. If you find that the tractor is not properly ballasted, adjust it according to the manufacturer’s ballasting recommendations for weight split, total working weight and wheel slip.

Generally, the weight split will be 35 percent front, 65 percent rear. Once the tractor is properly ballasted, proceed to Step 3.

Poppa · Apr 7, 2004

( When I think about the older tractors I think about a great big lever. As much weight as possible was placed forward of the rear wheels to off set the weight and drag of any implement placed on the back of the tractor. If I am wrong then I apologize and ask for enlightenment.
Am I in Left field? /forums/images/graemlins/crazy.gif
Are we (well not me yet /forums/images/graemlins/frown.gif) overloading these CUTs
)

I don't know if it is Kosher to reply to yourself but I felt in this case I probably should.

The answer is no I am not in Left field, heck I never made it to the ball park. Knowing that I have never been the brightest bulb in the pack it just took me all day to realize why I am wrong.

For me to get a handle on this whole idea, I kept having to think of an old Ford N or JD B or something along that line. I kept thinking about keeping the tractor from doing an instant back flip whenever a plow hit the dirt. While that is important enough to help inspire the 3ph in the first place, I missed two huge problems with my idea that most of the weight was originally placed forward of the rear wheels.

The first is traction, A topic often discussed here and ignored by my Post. If the weight isn't on the Drive wheels then they spin, pure and simple. The second problem is that if they had put that much weight over the skinny front wheels then the first time it was too muddy, the tractor would just bury the front end until the rear wheels lost traction.

The 60:40 or 65:35 ratio back to front does answer all three of my questions. The back wheels get traction, the front wheels aren't so overloaded they become trenching tools. But there is enough weight forward to help stop the back flip assuming reasonable use of a rear implement. Heck, forty percent of 5000 lbs is still a ton (literally /forums/images/graemlins/laugh.gif) of weight forward of the rear wheels.

So, even though I am still not sure whether these tractors are truly built to use a FEL to their full capacity I have definitely learned some good stuff.

Thanks and I apologize for my ignorance. At least At my age I have learned that whenever I start to think I am the smartest person in the room. A red flag goes up in my brain suggesting that I am wrong or the room is empty /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

Mike

gone · Apr 7, 2004

Hey, two diffrent weight bias suggestions off the internet sites tire manufactures, 33% fr-67% rear ,and 35fr-65% rear how can the guys that build these things differ in opinion? maybe theres more than one formula? no that can't be sience is sience right.

Henro · Apr 7, 2004

Hey, two diffrent weight bias suggestions off the internet sites tire manufactures, 33% fr-67% rear ,and 35fr-65% rear how can the guys that build these things differ in opinion? 

I think in the practical world ( where I don't live all the time... /forums/images/graemlins/grin.gif ) they are essentially the same numbers... /forums/images/graemlins/smile.gif

keeney · Apr 8, 2004

A machine that is purpose-built to use a loader would look a lot more like an articulated wheel loader with the engine in the back and big wheels in the front. Skid-steers also have the engine in the back. This configuration lets you use the engine weight also as ballast, puts the operator where they can see, and puts a heavy-duty axle and wheels under the fulcrum point of the loader.

Putting a loader on the traditional tractor configuration is a compromise design that lets you get multi-purpose use of a machine that's orginal design intent was to pull ground-engaging implements like a plow.

Another issue is weight. The traditional tractor configuration (along with the 3-pt hitch configuration) is intended to maximize traction without becoming so heavy as to overly compact the field it is driving on.

So another big differences is overall weight. Even a small skid steer is typically upwards of 7500 lbs. Most CUT's discussed here are in the under 5000-lb class. It takes some pretty tricky engineering to build a machine that can lift more than its own weight cantilevered outside of its wheelbase.

So, to make the compromise work better, add ballast to the back.

- Rick

jmc · Apr 8, 2004

JCA,

If you're serious, I think you could measure the distribution as you loaded it on a two wheeled trailer. Someone tell me if this logic is wrong.

1) Hook up the empty trailer and measure the height of the hitch.

2) Make a chalk mark on the bed directly over the trailer axle.

3) Drive the tractor up on the trailer until the hitch height matches the empty height measured previously. The tractor is now balanced over the axle.

4) Make anothe chalk mark on the bed at the midpoint of the tractor's wheel base.

5) Divide the distance between the two chalk marks by the length of the tractor's wheel base. At .1, its 60%/40%. .2 =70/30. .3=80/20 .4= 90/10, and of course, 0 is 50/50.

John

LBrown59 · Dec 31, 2004

( One trick I've used recently when the FEL is a little full and heavy, is to extend the backhoe a little farther back. This helps shift the center of gravity to the rear and provide some temporary stability for that extra heavy load from time to time.

)

You could also add more weight by filling the hoe bucket with dirt or something.