Ballast Wheel weights or filled tires?

[ozzie tractor]

one of the reasons they quoted for the fuel consumption was that when the wheel turned the fluid stayed basically where it was in relation to the ground except for the fluid in contact with the tire and rim, it got dragged around inside the wheel and it was this drag effect which caused the extra load on the tractor.

 

[soxfan]

Thanks for the advice, Some good points! Those are some sweet tire mods Jerry G. I like the flexibility of being able to take them off if needed, something I would not be able to do with filled tires. I am also not too concerned with the fuel efficiency of filled tires. It seems I can go for a couple of days on 10 gallons What overpriced weights does Kubota sell and how do they attach? Thanks again guys this forum is Awesome. I don't post much but I read everyone elses posts and have learned a bunch. Thanks again.

 

[JerryG]

Why wouldn't they? The tires are not filled completely so the tires can still conform to the ground.
Something is still missing to explain the results.

Either Michelin or Firestone one explains the whys about the fluid not letting the tire conform to the soil. You can go there if you wait to get into more detail. The jest of it is that the tire is more solid and that prevents the conforming.

 

[Harvster]

What is the explanation for decreased work and poor fuel consumption from fluid filled tires?

I would say part of the difference is due to location of the weight. With filled tires the tractor has to move weight that is centered further away from the axle center. This takes more energy than moving the same weight but distributed more closely to the center of the axle. Kinda like figure skaters spinning with their arms out vs arms tucked in. It's faster/easier to spin with the weight being more inline with the rotational axis.

 

[guyrj33]

If you ever have to drive over soft ground, don't fill your tires.
Use wheel weights or a 3 pt weight box. Then you will have a choice to weight or not to weight.

 

[KeithInSpace]

My engineering perspective: If you FILL the tire (I mean full...like 90% or 95% full) with fluid, the net effect on the tractor from a center-of-gravity perspective would be identical to having equivalent wheel weights...half the fluid weight would be below the axle and half above. Straight physics, here. Advantage: None

I calculate that you could get over 2 cubic feet of fluid in each tire of a 2230/2350. At 62 lbs/cf you could get over 130 lbs of ballast in each tire versus about 70 or 80 lbs per each wheel weight. Advantage: Filling

It makes sense that non-compressible fluid filling would mean the tire would not 'conform' to the ground as well. It is this same principal that gets you stuck if you drive on a sandy beach with 40 psi in your tires versus 15 psi. Trust me...been there, done that. Advantage: Weights

Just my $0.02, but I've seen quite a few reasons why filling tires can be a pain in the butt and haven't seen where wheel weights are a pain. And when it matters to me, I probably have a box blade on the 3PH anyway.

I guess you could have a better net effect (from a COG/Physics perspective) with filling your tires and still have some ground-conformance capabilities if you only fill the tire, say, 50% or 60% with fluid. Then you'd hear your tractor "slosh" arond the yard. Funny thought.

I have wheel weights and see no reason to ever fill my tires.

 

[Harry c]

Another Engineering Perspective:
If you fill the tire to the top of the rim as recommended ( approximately 75% fill ) and pressurize with air to the recommended pressure (25 psi for my tractor) there is absolutely no difference in conformability to the ground except in extreme cases like running over a curb. 25 psi is 25 psi. The remaining air is compressible and acts exactly like air always does. The only difference is the smaller volume of air in the tire and the pressure rise will be greater with a significant deflection of the tire like the curb mentioned above. The pressure will be the same when you run over the curb but the tire will not have deflected as much due the increased rate of pressure rise because of the smaller volume of air available to compress. Normal running around on the ground: the tire will exert exactly as much pressure per square inch on the ground as the inflation pressure. 25 psi in the tire; 25 psi on the ground. The tire deforms to pressure equilibrium.

 

[N80]

Another Engineering Perspective:
If you fill the tire to the top of the rim as recommended ( approximately 75% fill ) and pressurize with air to the recommended pressure (25 psi for my tractor) there is absolutely no difference in conformability to the ground except in extreme cases like running over a curb. 25 psi is 25 psi.

Yes, that's the way I look at that too....but I'm no engineer. Plus, just from observation, my filled tires certainly do conform to ground conditions, particularly hard things like rocks.

I can understand the theory that moving the water around within the rim my cause a little wasted energy. In a tractor plowing hundreds of acres a day one might see a difference. I doubt there is any measurable difference in a typical CUT doing typical CUT type tasks.

Again, all things being equal, I like the idea of wheel weights. For me, it all comes down to price. Manhole covers might be an option for smaller tractors but on my L4400 I get 400 pounds per tire with fluid. A man hole cover can't get anywhere near that.

 

[MX5000]

I went back and fourth on putting liquid ballast in the rear tires of my 2005 Kubota MX5000 because of reading about a possible stiffer ride. I priced wheel weights from Kubota and was quoted $600.00. I put $100.00 worth of ballast and the rest was water to the nozzle in the 12:00 position in the wheel. I've got about 300lbs per wheel. I'm happy with the ride and doesn't seem any stiffer when driving fast on rough dirt roads or trails. Now the tractor doesn't bouce back and fourth (front to back) driving on steep trails with a full loader bucket. If needed, I can add wheel weights or ballast box (use the Woods BH900 Backhoe for rear ballast).

Howard