Get A Grip

Get A Grip

Besides traction, the right tire can cut costs and boost safety. Seven key areas to pay attention to when outfitting your fleet with snow tires.

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February 19, 2019

A good tire is a key tool for a snow professional. The right tire helps provide traction, improve fuel efficiency, and keep operators safer on the job. James Crouch, National Product Manager-Agriculture for Alliance Tire Americas, provides these details to look for when selecting a tire for a snow plowing or removal tractor:

Lug/void ratio
"The spaces between lugs -- the voids -- are as important as the lugs themselves when it comes to traction," Crouch says. "For maximum grip in the snow, you need aggressive lugs and enough voids between them to allow the lugs to dig in. Properly designed voids also allow the tire to eject packed snow to re-open the voids."

Biting edges
Look for lugs that have lots of edges that can bite into the snow. Irregular shapes might look odd, but they can provide more surfaces that claw their way to better traction.  Keep in mind that the amount of traction you’re able to achieve is directly related to the number of biting edges you put on the ground.  

Sipes
"These tiny slits in the lugs don't look like much, but as the tire flexes, they open up like little mouths to take a bite of the surface, adding a significant amount of traction," Crouch says. "That can be important not just in developing more pushing power, but also in helping you brake and steer more effectively."

Sharp shoulders
"Think of a sharp shoulder as a spade digging into the snow from the side," Crouch says. He adds that a sharp-shouldered tread helps ensure lateral stability when the tractor is operating at an angle on a road shoulder, hillside or snow pile.

Cold-weather compound
Ask your tire dealer about the rubber compound in your tires. "What we call 'rubber' in a tire is actually a very complex blend of natural and synthetic rubber and all sorts of other ingredients that are balanced to deliver specific performance traits," Crouch says. "Formulation engineers develop compounds specifically for cold weather, snow and ice. Those tires tend to be softer than the kind of tire you'd run on the road all summer. But that pliability delivers a lot more traction and better performance in freezing conditions, and it's backed up with other traits that ensure a long service life."

Flat footprint
A tire that lays flat rather than bowing up on the edges where it meets the road -- the contact patch -- is applying the force of your tractor more evenly on the driving surface, Crouch says. Bias-ply tires tend to form a crown, which leads to faster wear in the center of the tread, whereas radial tires tend to have a flatter footprint.

"You get better performance from a flatter contact patch because it develops traction across all the lugs and voids on the contact patch, and delivers your tractor's horsepower more effectively to the ground," he says. "You also get better fuel efficiency and more even wear on the tire, which go straight to your bottom line."

Crouch's tip -- If you can slide a credit card under the edge of a properly inflated tire where it should be in contact with the road, the contact patch isn't flat enough.

Steel belts
Steel radial belts under the tread help create a flat contact patch and effectively distribute the weight of the tractor evenly across the broadest possible surface. Woven steel belts combine durability with the strength to maintain the desired shape of the tread. Steel is also highly efficient at diffusing heat from the tire. That is often far from operators' minds on a snowy day, but driving home from a job over the road can create a significant amount of heat in a tire, which increases wear if it is not conducted out of the tire carcass.

Once you have found a tire with the tread pattern, compound and footprint you are looking for, be sure to operate it at the recommended inflation pressure, Couch says. Check load/inflation tables or consult with your tire dealer to determine the proper inflation pressure, taking into account the weight distribution on the tractor -- including a bucket full of snow or the weight of the snow blower or blade.

"That tire was designed to operate at a very specific inflation pressure," he says. "The profile of the tread, the flex of the sidewalls, the number of lugs in contact with the road surface all assume the proper inflation pressure. If you over inflate the tire, you can reduce the size of your contact patch and stiffen your sidewalls. If you under-inflate it, you can create distortion in the tread area that can actually lift the center of the footprint out of contact with the surface. Under inflation also makes your sidewalls too flexible, which can increase power hop or slip, decrease lateral stability, and lead to greater heat buildup when the tire is rolling.

"It takes 10 minutes of time and $5 investment in a tire gauge to get the most out of a set of tires, which is about a 500-percent return on investment," Crouch says.