|
WEAR & REPLACEMENT
It's a rare trailer tire that wears out, tread-wise. Lack of cornering
loads and low annual mileage mean trailer tires generally wear out
first from the effects of sunlight and ozone and other environmental
factors. The tire industry advises five years as a tire's lifespan
due to rubber oxidation. Given low annual mileage, often around 2,000
miles, that means a typical trailer tire accumulates only 10,000 miles
in five years when its time is up, even though a considerable amount
of tread rubber remains.
Tire companies say time-related damage is difficult, if not impossible,
to see. Constant exposure to the pressurized oxygen inside the tire causes
rubber breakdown relatively deep in the tire carcass. Outside, ozone
accelerates the oxidation process, which is definitely more severe in
smoggy urban areas where ozone is prevalent. A stored tire deteriorates
faster from interior breakdown than a tire in use, because flexing the
sidewall tends to release beneficial lubricants from within the rubber
A stationary tire thus has a greater tendency to dry on the surface.
We've already pointed out low tire pressures as the prime heat source,
but environmental heat is also a player. Tires in the egg-frying desert
states often die early, especially when combined with long, high-speed
tows. Well-cared-for tires in cooler climates will likely exceed the
five-year limit, but they are on borrowed time. Remember that impact
damage from curbs, potholes and leveling boards is cumulative, and if
you want to avoid trouble, adhering to the time limit is wise. To avoid
leveling-block-- induced stress, make sure that the leveling blocks are
wider and longer than the tire contact patch, and use ramped blocks if
ascending more than a few inches. This distributes the tire load evenly.
Next - Visual
& Maintenance |
