Why is Weight The Only Solution Being Offered To The Problem Of Traction?

[Jstpssng]

Maybe on a forum like this where most folks have small compact tractors with loaders. But look at any row crop tractor out in the field. Just about every single one of them will have weights hanging on the front of it. Imagine how much traction you need to pull a 60 ft planter across the field.

My first thought when reading the title was "Having the proper tractor is most important." Trying to pull a 9 foot disc with a riding mower isn't going to work... and not just because the mower is too light.

 

[airbiscuit]

Weight matters. So does having a taller diameter tire. The two usually go hand in hand. Consider a tug of war between a
Kubota BX 2680 - 24.8hp - 1521 lbs - 26x12x12 R4 rear
Kubota L2501 - 24.8hp - 2601 lbs - 15 -19.5 x(40) rear

Anybody wanna guess which one would win? I really like larger diameter tires. Size matters

 

[Cycledude]

Rest assured tractor manufacturers are constantly considering options but so far the Tweels are way to expensive that’s probably the main reason you don’t see them being used much.

 

[mo1]

For a "chore tractor" ,, not a field tractor,, IMHO,,
the number ONE thing a tractor can have to enhance traction is hydrostatic drive.

I think hydro drive even surpasses 4WD as far as traction improver,, especially with a novice operator.

I still remember the first time I plowed snow with a hydro Cub Cadet garden tractor,
instead of the previous gear drive Cub Cadet.

The tractors were identical except for gear versus hydro transmission,
(the gear was a 128 with a 14HP engine, the hydro was a 149 with a 14HP engine)

I could literally push 2X as much snow with the hydro.

Then I got an 855JD with a loader.
That tractor was amazing as to what it could do,, even in 2WD.

The 855 could do more in 2WD than my JD 650 in 4WD,,
and I believe it is due to the hydro transmission.

The only thing that a different transmission can do is to lessen the risk of the operator accidentally/unskillfully exceeding the amount of traction available when accelerating and turning the much higher coefficient of static friction into the much lower coefficient of dynamic friction when they spin the wheels while operating the unit. Assuming the hydrostatic transmission doesn't weigh a lot more than the gear transmission, there will be no change in actual traction as traction is determined by weight times coefficient of friction (which is determined by tires, inflation pressure, and the surface being driven over.)

A Deere 855 is noticeably heavier than a 650, so that is certainly a factor.

 

[Cahaba Valley Farm]

Rest assured tractor manufacturers are constantly considering options but so far the Tweels are way to expensive that’s probably the main reason you don’t see them being used much.

I think you're right.

 

[Cahaba Valley Farm]

Weight matters. So does having a taller diameter tire.

Please explain. What is the advantage of the large diameter tire over the smaller one?

 

[BnRidge]

Weight matters. So does having a taller diameter tire. The two usually go hand in hand.

A larger tire footprint would have more weight bearing capacity per given tire pressure. Larger diameter (or width) would provide that. (Tracks, even more.) Footprint size has no relationship to tractive force. It does allow flotation though so you don't sink out of site while trying to get that weight to the ground. If a comparison were done on hard surfaces, then diameter differences would have little effect.
Think of something like train wheels - very high weight, very high tractive force pulling a long train, relatively tiny footprint on very skinny but extremly hard tracks.

 

[Torvy]

Weight does more than just provide a boost to traction. It makes the tractor less tippy. Taller wheels may provide better pulling power, but they raise the center of gravity, making your tractor less stable. There are trade offs in many aspects of life. To me, a tweel has one advantage, it does not go flat.

 

[airbiscuit]

I'm not sure I can explain the physics of a taller tire. I can only say that I grew up on a farm and the tractors with small diameter tires were always spinny. I think it is more than ground footprint, but also the geometry/leverage of a taller diameter. Those old John Deere B's didn't have much power, but they had a ton of traction with those tall rear wheels.

 

[murphy1244]

I'm not sure I can explain the physics of a taller tire. I can only say that I grew up on a farm and the tractors with small diameter tires were always spinny. I think it is more than ground footprint, but also the geometry/leverage of a taller diameter. Those old John Deere B's didn't have much power, but they had a ton of traction with those tall rear wheels.

All about leverage. A taller tire is like a taller gear. Ie 4.10 verses 2.55.