Split Rim Wheel Dangersby Phillip Woolgar
Split rim wheels use a locking ring on the outside bead that holds the tire in place. One-piece rims have a fixed bead. With a split ring wheel, an average driver can change his truck's tire with only a jack and hand tools. The style isn't very common in North America, but split rim wheels are widely used in rural areas of India, China, and Central and South America. The rims are dangerous when misused or badly maintained.
After pry bars loosen the ring, just a few pounds of pressure can launch your locking ring, turning it into a projectile. This is especially problematic because you need to edge the lock ring loose when you change a tire. Safety administration bodies and manufacturers suggest removing the valve completely before touching the ring.
Given a large truck's standard 60 psi inflation pressure, nearly 12 tons of force pushes on the locking ring on the rim all the time. That kind of weight can cause any small crack or defect in the ring to form a weak spot. If the ring cracks, the rim explodes, potentially killing or injuring anyone in the locking ring shrapnel's way.
Any time your tire drops to under 80 percent of the recommended inflation pressure, the tire must be completely deflated. The ring must then be reset before the tire is re-inflated. The ring can shift out of its groove if the tire is under-inflated. When the tire is inflated, the dislodged ring can fly off the rim with the new pressure. Therefore, the tire must be inflated to over 80 percent of the recommended inflation pressure at all times.
All the components used in your split rim wheel must match. If you use a lock ring designed for different wheels, you could cause the ring to crack, leading to a possible explosion.