Gear drive vs hydro

[MossRoad]

even if I found an HST, used it and loved it (and became a new convert to the cult) I could not afford it.

But at least you could then say the Red Green man's prayer....

I'm a man....
But I can change...
If I have to...
I guess.

 

[N80]

So why not compare a China tractor to a JD? Using your analogy, nobody with intelligence would ever buy a JD tractor. Or NH, Kubota, Mahindra, etc. It you are just looking at spec sheets, the machines from China beat every other machine out there with specs VS $$.

This is a totally specious argument and is nothing more than a distraction. By this argument I could get a shovel rather than a tractor with a loader. It boggles my mind why the even money issue cannot be grasped by some. We are talking about HST vs gear. That's all, so injecting brand and quality into the issue makes no sense at all.

But, many people do buy JD, Kubota, etc. Maybe it's not as simple as "even dollars" ? Maybe productivity, ergonomics, learning curve, reliability, desirability, etc are also important?

Yes, and those things have been discussed. The even money point relates to the HP that you can buy with the money you have among otherwise comparable machines. How hard is that to grasp.

N80 - you need to look up drawbar hp. From your replies it seems you don't understand the concept.

You may be right, I may not understand the methods or units precisely. (Of course you might not be right, but I fail to see how that changes the points I've made either way.)

And seriously, if you recognize from my posts that I don't understand the concept them it certainly indicates that you do. So, if you would be so kind, please enlighten me (I'm not being sarcastic, I love learning about this stuff) and in so doing, please show me how my points regarding hp and/or torque are wrong.

I'm signing out of this argument now.

Please don't. I really want to know how I've mistaken my assumptions about drawbar hp and you seem to have a good grasp of it. Please share.

Have to go polish the pink paint on my HST tractor, armorall the R4's, wax the rims and add a new feather boa to the ROPS. If there's time, I need to put new rainbow paint on the tire treads to co-ordinate the manly look. Then I have to do the same to the 50,000 pound HST dozer and the 4 yard HST payloader.

I find it ironic that we get these sorts of replies when supposedly it is the folks who like our geared tractors that are the ones who are being portrayed as so defensive and irrational. We can acknowledge virtually all of the claimed advantages of HST but when we point out a few perfectly rational and easily proven advantages of a geared machine then all of a sudden we're the nut jobs.

 

[N80]

I just spit pop out my nose.

I pretty much think the only real value I bring to TBN is himor at this point. I'm glad someone gets it!

Love Red Green's man prayer. Do not want my wife to see it.

 

[N80]

N80 - you need to look up drawbar hp. From your replies it seems you don't understand the concept.

John, I took your advice and did a little research. As it turns out, my concept of drawbar horsepower was not only correct, but perfectly applicable to the discussion at hand. Drawbar horsepower in agricultural terms is the power to pull an implement. And that is exactly what I was referring to.

If you meant to say that I did not understand the specifics of drawbar horsepower, you were correct. I have remedied that. But again, my concept of it and how I applied it to this discussion was precisely correct.

And I guess what tipped you off was this comment by Dynasim which confused me:

Torque(drawbar pull) doesn't equal hp.

I'm still confused by this because drawbar horsepower is, in fact, a unit of measurement: dbhp. It is not simply a measure of torque, but I was certainly not in a position to question that. I thought maybe he was referring to how it is tested, which I still do not understand. In other words, does the tractor pull against something like a winch or coil that would give data in terms of torque? I don't know. Maybe someone can tell us about how the Nebraska tests are done.

However, what I do know now is that dbhp = force (ftlbs) x speed (mph) divided by 375 (the constant for 1 hp).

What Dynasim was trying to say, I do not know, he has not ellaborated.

But again, if we're talking about the power to pull an implement, and that is precisely what we've been talking about in relation to using ground engaging implements, my concept of dbhp was exactly right.

 

[art]

To see what the difference has been just by a set of tires or the weights used a poorly set up gear drive tractor would have difficulty keeping up with a well set up hydro!

Seen it to many times in the field that a larger tractor had difficulty pulling what a smaller tractor could!

 

[N80]

To see what the difference has been just by a set of tires or the weights used a poorly set up gear drive tractor would have difficulty keeping up with a well set up hydro!

Clearly, but what is the significance of it? And wouldn't the opposite be true? I think we all understand that HP is only one factor, but to discuss the advantages of HP, one has to assume everything else being equal. Right?

 

[Soundguy]

Then I have to do the same to the 50,000 pound HST dozer and the 4 yard HST payloader.

Are they really variable displacement pumps with swash plates.. or are they torque converter driven machines.. like the yellow equipment parke din my shop yard?

An HST and an automatic trans with a torque converter ARE NOT the same thing.. not by a long shot...

soundguy

 

[john_bud]

N80,

Drawbar HP.

Ok, here's the easy version without the math stuff that doesn't add anything anyway. Imagine a magic engine that makes a million HP and has the same weight as my 34hp kubota engine. (Go with me on this). But it is in a tractor that has totally bald tires. I mean teflon coated slicks. Now we compare that tractor with 1 million hp to my 34 hp kubota. Which one will be able to pull a greater weight the longer distance in the shorter time? Obviously the 34hp tractor, as the other one is only able to spin the tires. So, the million hp tractor would have zero drawbar hp. Right?

Now, imagine that the million hp engine in put into a tractor with a 3pt hitch that is 100 ft in the air, but with good tires. (I do have a point, stick with it). Which tractor has more drawbar hp? Well, the million hp tractor is pulled over backwards due to the 3pt hitch being so high and again it results in zero drawbar hp.

Now imagine that you put the million hp engine into a normal tractor with good tires. But, you attach a helium blimp to it that removes all but 1 oz of weight. Again, zero drawbar hp and the 34 hp tractor wins.

My point (since you stuck with it), is that drawbar hp is only limited on the upper end by engine hp, then parasitic loss like ps pump, hydro pump, transmission etc. Most tractors will give the identical drawbar hp no matter what transmission they use. I did state that previously in a clear fashion. The choice of tires, tractor weight, balance and the design geometry of the 3pt coupled with the wheelbase etc make the biggest differences, (greater than the trans type).

 

[Soundguy]

N80,

Drawbar HP.

The choice of tires, tractor weight, balance and the design geometry of the 3pt coupled with the wheelbase etc make the biggest differences, (greater than the trans type).

All great till you get to a point where you can stall the trns, and not stall the engine.. and not have tire slippage. IE.. plenty of weight / friction for all the traction needed.

On a tractor.. i want tires to slip.. or clutch to slip.. or engine to stall or the tractor to move... I'm unhappy with a revved up engine.. and stuck tires.. and a trans in bypass..... IE.. move or break.... My hand on the throttle is what -I- want to be the relief valve... .. that's just me.

The casual weekend warrior is probably happier with something that controls his destiny without so much hands on involvement..

soundguy

 

[N80]

N80,

Drawbar HP.

Ok, here's the easy version without the math stuff that doesn't add anything anyway. Imagine a magic engine that makes a million HP and has the same weight as my 34hp kubota engine. (Go with me on this). But it is in a tractor that has totally bald tires. I mean teflon coated slicks. Now we compare that tractor with 1 million hp to my 34 hp kubota. Which one will be able to pull a greater weight the longer distance in the shorter time? Obviously the 34hp tractor, as the other one is only able to spin the tires. So, the million hp tractor would have zero drawbar hp. Right?

Got it. That makes perfect sense.

Now, imagine that the million hp engine in put into a tractor with a 3pt hitch that is 100 ft in the air, but with good tires. (I do have a point, stick with it). Which tractor has more drawbar hp? Well, the million hp tractor is pulled over backwards due to the 3pt hitch being so high and again it results in zero drawbar hp.

Okay.

Now imagine that you put the million hp engine into a normal tractor with good tires. But, you attach a helium blimp to it that removes all but 1 oz of weight. Again, zero drawbar hp and the 34 hp tractor wins.

Again, I get it.

My point (since you stuck with it), is that drawbar hp is only limited on the upper end by engine hp, then parasitic loss like ps pump, hydro pump, transmission etc.

John, I'm listening, and I understand, but I don't think you are listening to me. This is THE VERY REASON that when you want to make fair comparisons you have to limit the variables like tires, weight, set up. That's why we say all-other-things being equal. I understand that less HP can outpull more HP that is not applied properly. NO ONE is arguing that.

Most tractors will give the identical drawbar hp no matter what transmission they use.

I don't think that is correct and I don't think that you can prove it. It does not make sense. At the same time, I cannot prove it is wrong either since I don't have any hard data.

I did state that previously in a clear fashion. The choice of tires, tractor weight, balance and the design geometry of the 3pt coupled with the wheelbase etc make the biggest differences, (greater than the trans type).

Yes, we get that. That is why you compare apples to apples. That's why this argument, this comparison, comes in two flavors:

1) Same exact tractors. Same tires. Same set up, everything identical except trannies. Due to the losses you described in the pump, etc, it is probable that the HST will deliver less dbhp, but as has been mentioned it will be trivial and maybe even insignificant.

2) This is the important one. I stayed with you, so you stay with me. Now we are talking about what you can buy for 'x' amount of money with dbhp being the issue. Keep brand and tires and all that equal and the primary variable, the primary thing you get less of, is HP. But sure, you could start introducing variables like poorly made, less expensive tractors but that just sets the discussion into a death spiral by introducing red herrings that do not help resolve the issue and have no real practical application. Few of us is going to buy a Belarus over almost anything else, just for moer HP.

And so, the fact remains that for all practical matters and for 'x' amount of dollars you can buy more HP (where ever you want to measure it) with a geared tractor than with an HST.

Why is that so hard to understand? Or more to the heart of the matter, why is it so hard to admit?