The leading factor in roadside emergencies is tires. Tires can lose their footing long before they're worn out. Tests conducted by Consumer Reports show that tread can give up a significant amount of grip when it's still at the halfway point. Because of this, USRider reminds equestrians and others who travel with horses to check the tires on tow vehicles and trailers regularly.
"Tires are considered bald when one or more of their grooves reaches 2/32 of an inch deep, compared with about 10/32 of an inch for new tires," said Bill Riss, general manager for USRider, the national provider of roadside emergency assistance for equestrians.
Manufacturers have made bald tires easier to spot by placing a series of molded horizontal bars at the base of the grooves. The bars become flush with surrounding tread when wear reduces a groove's depth to 2/32 of an inch.
With diminished tread comes the increased risk for an accident. As a tire wears, its ability to perform in rain and snow is reduced. Hydroplaning is more prevalent due to water standing on highways from heavy downpours. With 2/32" of remaining tread depth, resistance to hydroplaning at highway speeds is significantly reduced.
USRider recommends that horse owners check tire tread at least once a month. Additionally, since tire issues are the No. 1 reason for disablements with a horse trailer, it is recommend that horse owners check the tire tread on both their tow vehicle and horse trailer prior to each trip. The best way to check the depth of tire tread is with a depth gauge; however, U.S.-issued coins can be substituted for a tire tread depth gauge as tires wear to the critical final few 32nds of an inch of their remaining tread depth. Follow these guidelines from Consumer Reports:
- Place a penny into several tread grooves across the tire. If part of Lincoln's head is always covered by the tread, you have more than 2/32" of tread depth remaining.
- Place a quarter into several tread grooves across the tire. If part of Washington's head is always covered by the tread, you have more than 4/32" of tread depth remaining.
- Place a penny into several tread grooves across the tire. If the top of the Lincoln Memorial is always covered by the tread, you have more than 6/32" of tread depth remaining.
- Once you have determined the approximate remaining tread depth in the first location, you can complete your measurement of each tire by placing the coin into additional locations at least 15 inches apart around the tire's central circumferential groove, as well as in its inner and outer grooves. This will help detect uneven wear caused by mechanical or service conditions.
While inspecting your tires' tread depth, be sure to check for dry rot and check tire pressure as well. Trailer tires typically deteriorate due to dry rot from age before they wear out and should be replaced every three to five years regardless of tread wear.
In addition, trailer tires are more prone to uneven wear due to underinflation. Upon inspection of the tire, the outer edges of tread would show more wear than the center. This condition also leads to blow-outs.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.