Radial Versus Bias Performance

In order to choose the best tire for your application, we have summarized two common tire construction types that are commonly sold for off-road tires.

For the most part, the tire industry has dumped the bias tire for on-highway use, but bias type tires are still offered in the ATV and 4x4 off-road industry.

BIAS Constructed Tires:

For enthusiasts looking for ultimate in off-road performance (we are talking serious off-roading and deep mud), bias tires are still the best choice. For these applications, ride and wear characteristics on pavement are not a concern. Bias tires offer better cleaning characteristics for those extreme off-road situations. An application which has a high risk of sidewall damage would also greatly benefit from bias tire construction.  Their rubber compounds are typically softer which help grip rough and rocky terrain.

Bias tires typically have the ply cords that extend diagonally from bead to bead at a range of 30 to 40 degree angles.  Each successive ply is laid at an opposing angle, forming a criss-cross pattern.  The end result is a design that allows the entire tire body to flex, as the tread and sidewalls share the same casing plies.  The flex allows for better gripping, better clean out, and better conformity to terrain which allows for a smoother ride on rough surfaces.

This tire flex in the bias constructed tire is also its major disadvantage, depending upon the application.  Bias tires tend to wear out quicker and form flat spots compared to their counterparts.  The flexing also means increased rolling resistance, and less control and traction at higher speeds.  If you jump in a vehicle after a long cold night that has bias tires, you'll notice a "bounce" down the road accompanied by an obnoxious hum.  Typically the off-road bias tires will get 20-30K miles on them compared to the off-road radial tires that can achieve 40-50K miles.

Radial Tires:

It is advantageous to place a radial tire in an application where good traction is required on vehicles driven at high speeds, such as daily drivers and those that see both on and off-highway applications. They offer much better road handling and characteristics, than the bias tires.  If you want to drive your truck on a daily basis, or more than 40 miles on the highway in order to reach the trailhead, then it's pretty hard to beat the versatility of the radial tires.

Radial constructed tires utilize ply cords that extend from bead to bead at approximately right angles to the centerline of the tire.  They are parallel to each other, and are combined with stabilizer belts.  The result is a much stiffer carcass, longer tread life, better steering control and lower rolling resistance.

Summary:

	Advantages	Disadvantages
Bias	Strong sidewalls, tough casing Better sidewall puncture resistance Good lateral stability (hill side work) Good in rough terrain and off-road Self-Cleaning Easily repaired Lower purchase price	Poor life expectancy (50% of radial) Lack of flexibility in casing reduces foot print and traction Tread flexes more, generating more heat and rolling resistance. Profile of tire increases soil compaction and reduces traction
Radial	Good high speed capacity Longer lasting (Up to 50% longer) Wear resistant Low heat build-up Lower rolling resistance Better Fuel Economy Better floatation and larger contact area Less soil compaction Better stability and machine handling Smoother, more quiet ride Proliferation of tires in the last 10 years has mostly been in radial	More prone to puncturing More difficult to repair Higher purchase price

 

Notes: All radial tires have a designated "R" in the tire size. Example: 36x14.5R-15LT. If you don't see the R, its a bias type tire!