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

[npalen]

So then what you're saying is it's not just about contact area it's also about weight. A lot of contact area with not much weight is still not a perfect recipe for traction.

My college physics teacher posed this question to the class: If traction consists only of weight times friction coefficient and not contact area, why do racing slicks offer more traction? I don't recall anyone with an answer at the time but I think I know the answer after thinking about it for 50+ years now.

 

[Blue hood]

Old tractors used to have some kind of rims add-ons to help rear tires traction, besides the added weight it had an on/off manual spikes system. Who knows why this idea disappeared or has been replaced all together by other more heavy and expensive track systems.

Just thinking, if liquid filling it's not enough to improve traction, what about adding narrow solid rubber wheels without doubling the tractor's rear tires width.

 

[Blue hood]

Here is the old footage a was looking for. Brand name Dinabite

 

[Cahaba Valley Farm]

It's not a single reason really. Rather a number of factors.

Under most farming conditions....the rear tires do 90% of the tractive work....and carry more load (or capable of) than the front

So everything is made bigger.

And since they are fixed....clearance isn't a problem.

To have an equal sized front tire, the front axle would have to be considerably wider to clear the tire when turning ...so it doesn't come in contact with the engine or frame.

It would also be an obstacle to clear in front loader design

The other option is articulating machines.

But both larger/heavier front tires, axles, and steering setup as well as articulating would add significant cost for little gain for the average person.

They do make machines with equal size tires. Being the really large farm tractors. And some things like JCB TLBs. But if you look at the jcbs....they really didn't oversize the front tires to match the back. Rather comparing to an equivalent sized tractor....it looks as much like the rears we're downsized to match.

And back in the days of rowcrop farming and cultivating....smaller front tires was as much about visibility as anything

All that makes perfect sense.

 

[airbiscuit]

 

[airbiscuit]

 

[BnRidge]

IH634 and IH4166 had equal sized front and rear yet still able to steer and clear. It didn't seem to catch on though for some reason. The neighbors had an IH3588, which I always thought looked a little strange. But now that I see it again notice it was articulated and not mfwd. Seems like designs needed to evolve some.

 

[LouNY]

The IH 634 was very similar to the County series of tractors which were Ford based.
County 6;TractorData.com County Super 6 tractor information
They are a very clumsy tractor, not very maneuverable at all. Hard to get on unless the front wheels are turned.

 

[Cahaba Valley Farm]

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You know I totally forgot about fruit tractors. I have seen them before under specialty tractors but forget about that design so thanks for sharing.

When I look at your tractor picture in your avatar it seems to me that the design is replicating gears in a gear box thus creating a lever of force against the ground. The big wheels in the back moving and rotating against the small wheels in the front. Is this observation correct?

 

[LD1]

View attachment 732393

When you look at these pictures, it's easy to see some of the issues I referred to.

Can you see the issues trying to put a loader on that tractor? Or the visibility issues up front when trying to do roe crop work or something.

And the limited benefit that those higher tires give over smaller ones isn't significant enough to justify the cost, especially given the downsides that go with it.

If you need more traction ...it made more sense and was more cost effective to just move up a size or two to a bigger machine