craigsmith
Well-Known Member
[ QUOTE ]
This intrigues me. To follow the agricultural analogy, consider the shape of the tread on tractor tyres. In forward gear the tread pushes outwards like a plough, not inwards like a spade. There is a very good reason for this, as anyone who has tried reversing a tractor up a muddy slope will know.
[/ QUOTE ]It isn't really counter-intuitive. There's little analogy to anchoring.
The tire on a tractor must deal with soft mud in which it will never attain a good grip. The tread is designed to push that mud away and allow contact with more solid material underneath. Furthermore it isn't really a plough shape, most tractor tires I'm familiar with have alternating lines at opposite angles, not Vs:
As the tractor moves forward, the tread first meets the ground at the center of the tire, then moves outward as the tire rotates. The direction then alternates. In reverse, this tread would be pulling loose mud toward the center of the tire and causing obvious problems.
This is similar to car tires; many wet weather tires have an obvious V pattern, or side-to-rear design, that is intended to move water underneath the tire away to the sides as well as possible.
Another issue with reversing up a hill would be the transfer of weight onto the smaller front wheels, particularly a problem if the tractor is not 4WD.
Off topic?
Disclaimer: I am not a tractor or tire expert.
This intrigues me. To follow the agricultural analogy, consider the shape of the tread on tractor tyres. In forward gear the tread pushes outwards like a plough, not inwards like a spade. There is a very good reason for this, as anyone who has tried reversing a tractor up a muddy slope will know.
[/ QUOTE ]It isn't really counter-intuitive. There's little analogy to anchoring.
The tire on a tractor must deal with soft mud in which it will never attain a good grip. The tread is designed to push that mud away and allow contact with more solid material underneath. Furthermore it isn't really a plough shape, most tractor tires I'm familiar with have alternating lines at opposite angles, not Vs:
As the tractor moves forward, the tread first meets the ground at the center of the tire, then moves outward as the tire rotates. The direction then alternates. In reverse, this tread would be pulling loose mud toward the center of the tire and causing obvious problems.
This is similar to car tires; many wet weather tires have an obvious V pattern, or side-to-rear design, that is intended to move water underneath the tire away to the sides as well as possible.
Another issue with reversing up a hill would be the transfer of weight onto the smaller front wheels, particularly a problem if the tractor is not 4WD.
Off topic?
Disclaimer: I am not a tractor or tire expert.