When the Rubber Hits the Road

August 12-18, 2019

By one definition, farmers are in the transporting business. We move soil around to prepare the fields for the little seeds we sow. Vans, wagons, trailers, trucks, and tractors go hither and yon on a daily basis to harvest and tend to the crops. We haul hay and feed and then haul livestock to the butcher. In the busiest season, we deliver produce to customers in the form of a CSA or farmer’s market five days a week. Thanks, in part, to one piece of technology, all of these chores are possible: rubber tires. Everything we move around rides on them, and with all the work that tires do, they don’t get the respect they deserve.

The wheel was invented 3500 BC, but it wasn’t until 1839 AD that Charles Goodyear cooked sap down like sorghum, adding in sulfur and a few other ingredients to create the rubber tire.  Before that humans rode around on stiff steel or wooden wheels. It was only later in 1887 when an Irishman named Dunlop, in order to improve his son’s tricycle, invented a way to inflate rubber tubes with pressurized air.  At that time transportation became faster. Rocks, dips, and sticks no longer sent shock waves jolting up to the bed of the conveyance with this cushioning pneumatic system, and a rubber layer around the wheel greatly cushioned the impact and aided in transporting goods.

Today, tires are quite sophisticated, and we depend on all kinds of tires to keep our business rolling at the farm, with few being interchangeable. Trucks, wagons, carts, trailers, and some implements all use similar looking tires on metal rims, but the visual appearance is where the universality stops. First, the diameter of the spindle (the hole in the middle of the rim) must match the rim exactly, and the lug pattern (the bolts on the vehicle that the rim attaches) also needs to be identical to the rim. Lug patterns range from a four for lighter builds to a six or eight for newer trucks.

Now, it really begins to get complicated. When the tire bolts onto the hub, we must consider the diameter of the steel rim itself. Rims have gotten bigger over the years and are measured in inches across the diameter of the rim. In our collection of tires that we can reuse on wagons and trailer, we are in a quagmire of 15s and 16s, with a few 14s hanging in there, and a smattering of 13s down to 8s. Rubber is pliable, but you can’t stretch it.

The dimensions of the tire vary greatly as well.  A 275/75 R16 is a sixteen-inch radial tire with a tread width of 275cm and the height from rim to tread is 75% of 275cm, making it 206.25cm. We can use a 285/75R16 if a 275 is not readily available if it is on an independent axel, but if on the opposite side of a drive shaft, both tires have to be the same size because a 285 revolves a little slower than a 275 and drive shafts and transmissions can’t handle that. I told you that it could get complicated.

Tractor tires are unique in that they have solid rubber cleats molded into the tire for gripping power. This is especially important for a wheel pulling heavy implements up and down hills or when conditions are wet and muddy. In addition to their unique tread, tractor tires are often filled with calcified water rather than air. The water weight helps lower the center of gravity and increase the overall mass to handle big equipment, and the calcium keeps them from freezing.

With well over 200 tires on the ground, fixing flats is part of farming. The tricky occurrence is when a tire goes flat in the mud or on the side of a hill. All manner of blocks and chocks are gathered up to safely elevate the disabled equipment. Heavy loads can challenge an older tire’s ability to hold up, making a seemingly fine tire become useless. Sometimes our air tank will resurrect a tire with a slow leak in the valve stem or when it is not perfectly sealed. Other times we can ride on low tires, or air up the faulty tire enough to keep it from coming off the rim while moving the vehicle back to the barn.

With all the advances in tire technology, we can move crops, dirt and livestock around way faster than those who first cultivated this land. We can haul loads or people more quickly from place to place, and nowadays, we have dozens of different tires that keep us going. Rarely does a flat shut down operations, and roadworthy vehicles and trailers leave the farm in good shape, but unexpected things happen from time to time. Between spares, tubes and Teddy our tire guy, Elmwood Stock Farm keeps good food rolling from our fields to you, but dang, it’s not easy to keep all those tires aired up.   – Mac Stone

In Your Share

  • Cabbage
  • Garlic
  • Kale
  • Onions
  • New Potatoes
  • Rutabaga
  • Summer Squash
  • Surprise Me!
  • Salad Tomatoes
  • Slicing Tomatoes

Recipes

Check out our Pinterest board for this week’s recipes! https://www.pinterest.com/elmwoodstockfar/recipes-2019-summer-csa/

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