What's With Tractor Wheel Sizes

[RobertN]

Re: What\'s With Tractor Wheel Sizes

Part of it is $$$$$ On my 2wd Farmall, those smaller skinny front tires are like ~$60/ea, compared to $250/ea for the bigger rear tires.

Also, even with power steering, it would be harder to steer big tires on the fron of a tractor.

Larger front tiers would stick out further when you turn, ppossibly knocking around crops.

RobertN in Shingle Springs Calif

 

[patton]

Re: What\'s With Tractor Wheel Sizes

In the field of ag tractors, 4WD refers to a tractor that is full time 4WD and typically requires 4WD to acheve it's rated drawbar pull. A 4WD tractor is ballisted to put almost half it's weight on the front axle. Articulation is needed because a) the tractor is so damn big and b) the tractor is always in 4WD. You will see the same design in large loaders/intergrated tool carriers, while smaller 4WD loader-backhoes use the smaller front tires and part time four wheel drive like an equiivent farm tractor.

Front wheel assist, MFWD, part time 4WD, etc are designed to only be used ocasionally in 4WD, and a loss of turning radius is acceptable. Besides which, the tractors are fairly small and have a good turning radius to begin with.

They are ballisted heavier than 2WD, but not as heavy as 4 WD.

Pat

 

[RobertN]

Re: What\'s With Tractor Wheel Sizes

Gosh, I speel terribly! I gots to watch my posts beeter!

RobertN in Shingle Springs Calif

 

[thebonepile]

Re: Cultivating

Yes you are quite right, however, back in the older days before chemicals and super growing corn it was necessary to cultivate corn that was quite tall. With a wide front tractor the corn had to be able to go under the front axle without breaking off - so, once corn gets about waist high it is getting too big to go under the axles. However, with a narrow front tractor the lowest thing the corn had to go under was the rear axle, and you could cultivate corn almost shoulder high and still have it not break off.

As far as loaders, a narrow front can turn much better, but not worth a crap in the mud, and balance isn't as good, plus MFWD is not an option on narrow fronts

 

[thebonepile]

Re: What\'s With Tractor Wheel Sizes

the crop cultivating and price of the tractor were probably the main reasons for narrow front tractors (as everyone else says here)

I can put my two cents in.......

the narrow front wheels are cambered a lot to help clean mud out - as the wheels turn if mud gets stuck at the bottom as it goes up the back and the gap gets wider it will spin out.....

they turn much better than wide fronts, back in the older days of mowing hay with a sickle mower you could make tight perfect corners without missing a bit on every corner, plus implements weren't as big so it was nicer to turn sharper on the ends and get back going the other way easier..

Enough on that, now for the back tires......
tire companies have researched and found that a taller tire will transmit better and more traction to the ground - therefore, if you compare 2 ag tractors like a Allis wd45 to a big new John Deere (they now come with upto 46" tires) even if the weight, horsepower, everything else was identical, the one with taller tires would have better traction and power transfer to the ground. But there is a tradeoff, just like others mentioned in the post, would u like tires 8' tall on an 8n? and what about visibility, etc......plus on many MFWDs now - they size the front tires so the drivetrain/axle is centered on the tire - saves a lot on mechanical parts (compare modern things to Belarus' of a couple years back)

that's all for now.....

 

[Bird]

Re: What\'s With Tractor Wheel Sizes

<font color=blue>the narrow front wheels are cambered a lot to help clean mud out - as the wheels turn if mud gets stuck at the bottom as it goes up the back and the gap gets wider it will spin out</font color=blue>

Bonepile, that sounds perfectly logical to me, but sometimes the reality is different. I have a neighbor with an old Farmall with the narrow front end, and in this black clay in my area, it will just build up some much mud that the wheels quit turning. So what he has to do when he uses it in wet weather is take one front tire and wheel off and drive it with just one front wheel.

Bird

 

[Thomas]

Re: What\'s With Tractor Wheel Sizes

I agree about the narrow front end in turning sharp corner plus getting rid of the mud.
Pulling load of bale hay going down on a side hill I would rather have a wide front end,also travel down the road.

At one time one could purchase tire scapers for the narrow front ends to help keep the tire clean of mud and snow...wonder if they still sell them.

The tall the tire I feel less chance of getting stuck but one does make deeper ruts,plus the tall the tire for winter use w/good set of chains on can go about anywhere.

The down side of tall tires when one tire spins in mud and w/no fenders...arrrr. /w3tcompact/icons/crazy.gif

Even been going thru a field in high hay and have a narrow front end hit a chuck hole. /w3tcompact/icons/shocked.gif/w3tcompact/icons/crazy.gif/w3tcompact/icons/frown.gif


Thomas..NH /w3tcompact/icons/wink.gif