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

[BnRidge]

For a long time racers stubbornly insisted narrow tires had the same traction as wider tires.

They also spin up the tires just prior to using them. Does that somehow make them more sticky? Maybe there is something else going on there. Tractor tires generally don't go through that.

 

[Lineman North Florida]

Duels have been around for a long time, just might need to widen some gates.

View attachment 731987

One of the best ways to add traction and weight for farming operations, back before 4 x 4 was as popular as it is today, duals on farm tractors were common, I can remember when I was a boy drying out wet fields with a 3 point lift harrow and a JD 4440 with duals , when you would just about bog down I would lift the 3 pt hitch a little throwing more weight on the back of the tractor to keep me moving instead of getting stuck.

 

[Torvy]

They also spin up the tires just prior to using them. Does that somehow make them more sticky? Maybe there is something else going on there. Tractor tires generally don't go through that.

Traction on pavement is a different animal than traction in dirt.

 

[LouNY]

As far as the diameter of a tractor tire relating to it's traction the
Post #43 and #46 have the correct answers.
A simple way to illustrate it would be to roll a pencil across some dirt it's not going to roll worth a dang.
Now try the same roll with a coffee can it will roll right across it.
The taller tire has several advantages over a shorter tire in dirt, usually a longer foot print on the ground.
As well as the ability to roll over obstructions easier and to climb out of dips or holes.
In most tractor applications the taller tire will work better. In some instances tall and wider works better but
not always. In many instances if tires are the same height a narrower one will work better if the material
being driven in is soft with a firm base. Then there is the current condition for many snow a wide tire is not your
friend in snow it will have to run it's self up on top of the snow constantly and then it will be packing it under to make
more ice were a narrower tire will let much more spill off to the sides letting the tires get down and get a bit.

 

[MossRoad]

They also spin up the tires just prior to using them. Does that somehow make them more sticky? ....

A burnout cleans the tires of any dirt/oils etc. that may have been driven on in the pits and on the way to the line. It also heats up the tire to create better traction.

 

[jigs_n_fixtures]

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

NO!!! You have it backwards. A taller a tire is like a 2.35 vs a 4.10. A taller tire moves more distance per revolution. Thus more work per revolution.

A tractor designed for taller tire will have a higher numeric axle to compensate For the added lever length of the tire radius.

The advantages of a taller tire:

Ii gets you more clearance, and typically a larger contact area.

The angle of incidence is smaller. Think of the part of the tire just in front of the contact patch. It is at a lower angle than with a shorter tire. Think of that angle in terms of a ramp. Steeper is harder to go up.

 

[Cahaba Valley Farm]

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

This video reiterates what Murphy said about a tire being compared to a gear:

 

[Brendanspapa]

They appear to be a wonderful innovation, especially for paved or smooth surfaces. I don't believe they'd have much gripping power in the dirt. Weight is not the only criteria for improving traction, the amount of tread on the tire or the addition of chains can be another factor. Weight is probably the simplest and least expensive way to improve tractor traction.

Adding weight also improves stability. This is critical when using a loader and operating on slopes.

 

[MHarryE]

In the 60's with introduction of the JD 4020 and IH 806, standard tire was 18.4 x 34. That was soon changed to 18.4 x 38. Tractor company and tire suppliers used images of tread footprint on concrete using pressure sensitive paper showing that one additional V of lugs was in ground contact giving added traction. It was with those tractors that duals also came into play - I was young enough then that installing duals for field work and removing for haying was not such a back breaking problem. Then along came radials - virtually all ag tractors are now equipped with radials for the improved traction and reduced compaction. Most important, however, was MFWD. My example is pulling into a field for tillage and forgetting to switch on FWD. Notice I am going too slow, check my GPS and find it reading 3.5 mph vs tractor saying 5.0 mph. Tap the FWD switch and my GPS bounces up to 4.8 - 4.9 and engine power readout drops from 100% to 90%. More acreage covered per hour with lower fuel cost per acre - win win. Weight? Yes, loaded rears and either front end weights to keep it down or loader. But MFWD more important to traction than weight - and wish that someday I could afford a Quad-Track.

 

[fishdrivel]

Gravity is everywhere.....

 

[stuckmotor]

Harry Ferguson addressed the traction with reduced weight issue a long time ago.

 

[lpakiz]

Give me tall narrow tires in snow every time. In soft dirt, not so much.
Also, the taller tire has less rolling resistance. That's partly why the early Volkswagen cars in 194x something had those tall narrow tires.
It may also relate to "bridging" potholes or other road imperfection.
I don't know if that thought transferred to the Ford 2Ns, 8Ns and 9Ns.
I like the analogy of either a pencil or a coffee can on carpet. Pretty easy to see the difference in rolling resistance.

 

[kpsp50]

If you look at some of the videos of the farm tractors you'll notice that quite a few of them have dual tires on the rear some have dual tires on the rear and on the front if you look out west at the big farm tractors they have triples front and rear and that is for traction in the dirt

 

[Gord Baker]

Buy Ag. tires, Liquid Filled and if needed weight box. Don't over complicate.

 

[Flad]

It's A case of what you are doing, most tyres have a maximum tyre inflation pressure, the tractor has a tyre plaque on it or in the manual for tyre size and max pressure most suited to the machine. often lowering the tyre pressure to it's minimum working pressure or some where in between can make all the difference with traction issues and ground damage, this is often overlooked as most tyres are kept inflated to near or on the max allowable tyre pressures.
lower tyre pressures might reduce stability on hard or hilly ground but that is the trade off, tyre pressures should be adjusted to seasonal changes and ground conditions in your local area for best and safest operation, adding weight has a similar effect by forcing a bigger contact area with the ground also effecting stability and increasing ground damage, added weight can be a double edged sword, diff locks are a wonderful invention, knowing how and when to use the split breaks also helps in gaining traction, snow and ice are another kettle of fish I am glad I don't have to contend with.

 

[Bob Rooks]

Friction is defined as the resistance to motion of two surfaces - friction force (motion), and normal force (weight) (Newton's third law applies). μ = F/N where F is the frictional force and N is the normal force, and μ is the coefficient. The contact area of F/N can be increased by the deflation of tires and the height of tire lugs. μ is dependent on surface type and condition. So one can conclude that by just adding more weight makes the tires bulge and sink into the ground, tearing up and compacting the soil. In contrast consider the grousers F on a bulldozer track shoe - modest ground penetration compared to N. μ is multiplied by the number of shoes in contact with the ground. It's all well and good until you turn.

 

[Bob Rooks]

Buy Ag. tires, Liquid Filled and if needed weight box. Don't over complicate.

Understand that ASABE engineers jump through all sorts of mathematical hoops just so some people can over-simplify.

 

[Fielding]

Why are NFL linebackers not 90lbs?

Its the Laws of Physics, not the theory of Physics.

If you want to move 10tons, Its a lot easier if you have that much mass or more built in to the equipment doing the moving. Proper machine size and ballasting works wonders.

Being very heavy but with enough ground contact surface area for floatation gives best of both worlds.

If just trying to get max traction without worrying about compaction, being heavy as practical on the smallest surface area will be your best bet.

Also added mass lets you maintain momentum easier while pushing or pulling. Adding small amounts of energy to maintain motion, after the static friction has been broken, because the mass helps conserve the motion.

Learn about how ballast and weight balance works, then you will finally get the most out of the physical limitations of your “trac(tion) (mo)tor”

 

[Jstpssng]

People use R1 Radial tires, here in Europe, to get more traction amongst several other benefits, because they are wider, not because they are taller and skinnier.

Radials on the left, Bias ply on the right.

View attachment 732191 View attachment 732192

I know that you've answered this before but will radials fit on the same rim as bias? If not, it seems like tire construction isn't the only difference.

Somehow this discussion has turned into rocket science now

And here I am, asking dumb questions about rim width.

 

[ptsg]

I know that you've answered this before but will radials fit on the same rim as bias? If not, it seems like tire construction isn't the only difference.

The radials being wider, will need a wider rim at least for the front, but that's about it. Just like R4's, I believe? Never really dug into those tires much. It's also common to have front adjustable rims with Radials, just like the rears, while with Bias, only the rear rims are adjustable.