wheel And Tire Informational Guide - tire Repair Kit - Photo 29340833

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This tire-repair kit takes up little room and provides extra layers of defense against tire trouble. Extra valve stems, tire plugs, T-handle plug insertion tool, valve-core wrench, T-handle probe (for roughing up the hole's edges, improving plug adhesion), patches, and rubber cement round out the list. You should also carry tire irons (not shown).

Interco IROK: Bias Ply

BFGoodrich Krawler: Radial

This diagram shows a BFGoodrich Radial Mud-Terrain T/A KM2. Notice that the internal steel cords go side-to-side from one bead to the other. This cord orientation allows the tire casing to flex more easily. Radial construction doesn't "fight" itself as the tire flexes, so a radial tire runs cooler. Since a radial flexes more easily, it is more adept at absorbing small bumps and conforming to jagged off-road surfaces. Extra plies are added across the top (or "crown") of the tire to increase puncture resistance. The radial tire's internal construction costs more to produce than a bias ply, so a radial costs more at the counter.

"Bias ply" is actually a poor term. "Cross ply" would be a better description. In a bias-ply tire, the belts are arranged at crisscross angles, i.e. "on the bias." With a bias-ply tire, the sidewalls have the same construction as that of the crown. When a bias-ply tire flexes, the crossed plies "fight" each other. This internal struggle produces heat. The heat can break the tire down faster. Another byproduct of the cross-plies resistance is that the tire doesn't absorb small jolts as easily as a radial. What advantages do bias-ply tires have? Bias-ply tires are less expensive to produce, so they're easier on the wallet. Bias-ply tires tend to have tougher, thicker sidewalls compared to radials. Finally, the "dead" feeling of a bias-ply tire means that it won't bounce as much, which can be an advantage on steep climbs in the rocks.

The BFG Krawler was a breakthrough for radial tires in the rocks. BFGoodrich strengthened the sidewalls and chose a tread pattern and tread compound specifically for rock-crawling.

Pit Bull Tires offers both radial- and bias-ply models in its lineup. Shown is the Maddog LT Bias. Super-tough sidewalls and an aggressive shoulder tread pattern are two reasons this tire works great in the rocks.

Bias-ply tires don't flex as easily over jagged surfaces. Airing down further than you would a radial lets them conform to rough ridges. Super-low tire pressures almost always call for beadlocked wheels.

Spares at the ready in a Baja pit.

This tire-repair kit takes up little room and provides extra layers of defense against tire trouble. Extra valve stems, tire plugs, T-handle plug insertion tool, valve-core wrench, T-handle probe (for roughing up the hole's edges, improving plug adhesion), patches, and rubber cement round out the list. You should also carry tire irons (not shown).

You'll need an air source, too. The Powertank is a long-time favorite.

Adventure or disaster? The supplies and knowledge you carry make the difference.

Steel wheels have been around for eons. They're relatively inexpensive and easy to repair. Several styles are available, giving steel users choices when it comes to looks. Under stress, steel wheels will bend instead of breaking. They can be repaired in the field by pounding them back into shape with a hammer and a block of wood or a punch. This is cool: Black Rock Wheels makes its wheels in-house in the USA. We're taking a trip to the factory soon for an upcoming story.

Here's an aluminum Black Rock Viper wheel. Like almost all aluminum wheels today, the Viper is a cast wheel. Aluminum wheels won't rust, are lighter than steel, reduce rotating and unsprung weight, and come in seemingly endless styles. They're not as easy to repair as steel wheels, but we found out that it's still possible to repair an aluminum wheel. More on this later.

Backspacing describes the measurement between the wheel's inward-facing edge and the wheel-mounting surface.

Wheel width is measured on the inside from bead seat to bead seat.

Offset describes the relationship of the wheel-mounting surface relative to the central plane of the wheel. Negative offset means that the wheel-mounting surface is toward the vehicle. Positive offset means that the wheel-mounting surface is toward the street.

Here's a cross-section of a wheel with an OMF beadlock on the outside and an OMF weld-on reinforcement ring on the inside.

OMF Performance's Daraugh "Bones" Flynn demonstrated tire mounting for our lens. Trying to mount a tire this way, over the wheel's bell half won't work. That's because the distance between the lip of the wheel and the wheel's drop center is too great.

Here's the right way. Mount the tire over the wheel's nose half. Place one side of the bead into the wheel's drop center. With the bead in the drop center, you'll have enough wiggle room to ease the rest of the bead over the wheel's lip.

After the first bead is over the lip, repeat the procedure with the second. Although not shown here, lubricating the beads with soapy water makes the process easier.

Here's a pair of OMF aluminum reinforcing rings. The larger ring on the left welds to the outside, and the smaller one welds to the inside. You'll have to make sure there's enough caliper clearance for the inside ring. "A few years ago, we had a wheel company come to us," said OMF's Tim Orchard. "They needed their wheels to meet a 3,500-pound load standard test. Their test wheels were failing at 2,300 pounds. We added reinforcement rings to a wheel, and it more than passed. They stopped testing it at 4,500 pounds and it still hadn't failed."

OMF can add beadlocks to most aluminum wheels. Here's a Mickey Thompson Sidebiter wheel with an OMF beadlock installed.

Here's a cast-aluminum wheel with the center broken out. Cast wheels usually don't bend. They break instead. It took one monster-sized hit to destroy this wheel.

Same wheel, different angle. Cast wheels can be repaired, but it's often cheaper and easier to just buy a new wheel.

Instead of one hard hit, this wheel took 30 miles of off-road abuse while running wide open on a flat tire. Yes it's bent and mangled but no big chunks are missing. This wheel isn't cast, instead it's a spun wheel. Spinning is somewhat similar to forging in the sense that the wheel is shaped while in a solid state. By contrast, a cast wheel is made by pouring molten metal into a mold. The inner lip of this wheel was left stock and unreinforced.

Here's the other side of the same wheel. The beadlock kept the wheel's outside edge intact. The ultimate combo is to run a beadlock on the outer lip and a welded reinforcing ring on the inner.

We've raved before about the toughness of Walker Evans beadlock wheels, and here's photographic proof of their prowess. The wheel looks good as new even though the tire is completely mangled.

Yes, this wheel can be repaired. Note that the other side of the wheel has a beadlock welded on. A reinforcement ring might have saved the damage to the inner lip.

Here's another damaged aluminum wheel that can be repaired. "Potholes, curbs, and accidents in general are the main causes of wheel damage," said Carlos Orozco of U.S. Wheels Remanufacturing.

Here's a wheel with some light damage. Different types of damage require different tools and techniques to fix.

Carlos demonstrates a straightening technique that uses a specially-made prying wrench.

Polishing is another service offered by U.S. Wheels. This polishing machine is big and powerful, requiring caution and skill for safe operation.

Polished wheels, before and after. Huell Howser moment, anyone? "That's amaaazing!"