Tires Why Small Front Tires?

[catvet]

I imagine this has been discussed in the past but I didn't come up with anything useful with the search terms I used.

Why do most tractors have small front tires? It would seem to me you could support more weight (FEL) and possibly get more traction in 4wd if the fronts more equaled the real tires. For instance if you look at the M-series from Kubota many have them have front tires which are more inline with the rear tires.

Does it help steering? Keeping the tractor level? Allow for impliments to be attached? Stability?

Inquiring minds want to know.

 

[jimmysisson]

Front wheels steer, need room to turn. Easier to see what you're doing with less tire in the way. Easier to configure the loader arms. Lighter steering gear with smaller footprint/leverage. Less expensive. Tighter turning radius possible. Easier access to engine and accessories. Historic design inertia. Probably more...
Jim

 

[N80]

 

[radman1]

Don't see those high crop tractors in my area. I bet the turning radius on those things are horrible but I suspect they could go through a major mudhole. I only see those units in brochures.

The opposite extreme are the orchard, vineyard tractors.

http://www.deere.com/en_GB/products/brochures/agriculture/tractors/yy0614116_5015FV.pdf

 

[catvet]

George,

Exactly my point. Is that Kubota's "Mudder"? I spend a lot of time in mud. Looking at that tractor makes me think with larger fronts I wouldn't get stuck as often

 

[LBrown59]

I imagine this has been discussed in the past but I didn't come up with anything useful with the search terms I used.

Rite you R
It has

 

[Robert_in_NY]

George,

Exactly my point. Is that Kubota's "Mudder"? I spend a lot of time in mud. Looking at that tractor makes me think with larger fronts I wouldn't get stuck as often

Yes, that is their vegetable/mud tractor. But just look at it and if you ever saw one up close or operated on one you would realize how terrible the design is for every day use. It is a specialty machine designed for where you need high ground clearance. It has poor visibility, no loader option, poor turn radius, poor access to just about everything but they are great for working in vegetables.

 

[Egon]

Most Loader specific equipment is articulated and has the same size tires all around.

 

[plowking]

A neighboring town has a JCB Loader backhoe, it looks like a conventional TLB ,except it has same size tires and four wheel steering. plowking

 

[Robert_in_NY]

Most Loader specific equipment is articulated and has the same size tires all around.

That is true, except an ag tractor isn't loader specific. And adding an articulation joint into a tractor just so you can have equal size tires or re designing the rear axle so it can steer will add a lot of money to the price of the tractor for what gain? Better in the mud? How often does everyone get stuck in the mud with R-1's on a FWA tractor? Usually if you do it is because you have an implement that gets hung up in the mud (transport disc is what does me in), having 4 equal size tires won't do much good except dig deeper holes unless you have 3pt equipment that lifts high enough to clear the mud.

 

[Robert_in_NY]

A neighboring town has a JCB Loader backhoe, it looks like a conventional TLB ,except it has same size tires and four wheel steering. plowking

New Holland has one also (at least they use to), they are designed for jobsites where there is a lot of mud. But they are considerably more expensive.

 

[daTeacha]

I see quite a few high wheel spray rigs designed for spraying row crops after they are 2 ro 3 feet tall. High wheels and tires all around -- the things look like they could just drive over a car without touching it, clearing both sides and the roof with ease. They maneuver pretty well, but again, it's a dedicated single purpose machine.

 

[Eagleview]

This is the New Holland LB115 backhoe i traded when i bought my New Holland TL100A tractor . It had equal sized wheels all round , it was a real pain trying to see the bucket because all you could see were the tyres .

 

[flusher]

I imagine this has been discussed in the past but I didn't come up with anything useful with the search terms I used.

Why do most tractors have small front tires? It would seem to me you could support more weight (FEL) and possibly get more traction in 4wd if the fronts more equaled the real tires. For instance if you look at the M-series from Kubota many have them have front tires which are more inline with the rear tires.

Does it help steering? Keeping the tractor level? Allow for impliments to be attached? Stability?

Inquiring minds want to know.

Small front tires? Steering ease, mostly. No need for large front tires on a 2WD tractor where all the traction comes from the rears.

True 4WD tractors like the venerable articulated Steigers have the same size tires front and back since all the wheels are involved nearly equally in providing traction.

MFWD tractors generally have larger front tires than 2WD tractors, but these fronts are still quite a bit smaller than the rears. These tractors are front-wheel assisted drive tractors with the rear wheels still providing most of the traction.

 

[pat32rf]

If you look at the size of the rear drive axle then think of how massive the drive gears would have to be in the front steering gear to transmit that torque you will realize why the fronts are smaller in a CUT. The larger tire puts a lot more leverage on the drive train. The rears don't need a steering knuckle and carry most of the load. (not to mention the visibility and turning radius factors)

 

[catvet]

Thanks for all the feedback. I keep trying to understand why things are the way they are. I can see that smaller front tires make sense in the tractor world.

 

[Robert_in_NY]

Here are some better pics of the Kubota mudder

http://i23.ebayimg.com/07/i/000/fd/57/f3f0_1.JPG

 

[Robert_in_NY]

I was thinking of this thread and remembered the old Ford County tractors that had same size front and rear tires. Basically they were Ford tractors converted to 4wd. Here is a Super 4, it looks neat and would have great traction but unless you have 4 wheel steer, brake steering or an articulation joint it will take a lot of room to turn around.

 

[Rara Avis]