You may have heard someone referencing the tire bead or tire bead gap and thought to yourself..."WTF is that?". No worries, we're here to help explain what a tire bead is, why tire bead gap on your wheel matters, and offer some suggestions on how to choose the correct wheel and tire combos.
The Basics
If you've never actually mounted a tire to a wheel (bike, car, utv, etc.), it's easy to assume you simply fill the tire with air and it magically inflates and stays on the wheel. What makes the magic actually happens is a combined effort between your favorite wheel and tire companies. There are a ton of safety measures both wheel and tire manufacturers take to ensure each product properly beads, has ample strength for side impact, and guarantees that the bead stays in place.
What you need to consider is that if you alter the recipe of this process (lowering air pressure below suggested psi, or going speeds not recommended for both wheel or tire), you're going to test the limits of these safety measures and you'll be putting you and your passengers in harms way.
Let's address each of the parts and pieces that make a successful tire and wheel combo.
Tire Bead
The tire bead is the term used for the edge of a tire where the rubber makes direct contact with the wheel. The tire bead is a super stiff loop of coated steel wires that are tightly wound to exert pressure on the outer lining of the tire. The function of a tire’s bead is to firmly adhere the tire to the outer surface of the wheel. It does this by using pressure from the wires to mold the rubber to the wheel’s frame. The bead forms an airtight seal against the wheel and allows for a more efficient transfer of forces as the vehicle moves. The rubber compound that surrounds the tire bead reduces the flexibility of the wires and deflects damaging forces, especially in harsh environments like rock crawling or hard turns under speed.
Wheel Tire Bead Gap
In the example below, you can see where the tire bead sits directly between the wheel and the beadlock ring.
