What Is a Tire Bead? Understanding Tire Beading

If you’ve shopped around for off-road wheels, you may have heard the term “beadlock” as an option. You may have even heard that beadlock wheels aren’t typically street-legal. We discuss beadlock tires at length in a separate article, but this probably got you thinking: What is a bead? What does a “tire bead” mean? How does it relate to a car's wheel? 

A tire’s bead is the specific part of the tire that contacts the rim of the wheel. This thicker, reinforced part of the tire slots into a small groove in a wheel. Setting this bead in the groove of a wheel is sometimes referred to as “beading a tire.” When the tire is inflated, a seal is formed as the tire’s bead is forced against the sidewall of the wheel. The tension ensures that the tire can maintain proper air pressure. 

The tire’s bead appears as a thick piece of rubber near the ends of a tire. If you sliced a tire and laid it end to end, the tire would be shaped like a long upside-down U. The tire beads would be the tips of the U. When a tire is properly mounted and inflated you can’t normally see its bead. In fact, if you can see your tire’s bead, that may be a sign that your tire is under or overinflated and the bead has slipped out of its housing. Alternatively, it could mean that there was some damage to your wheel or tire and you need to repair or replace it. 

(Illustration of tire layers from FAASafety.gov)

Can You Fix a Bad Tire Bead?

If your wheel has recently come into contact with a curb or something else has collided with the side of your car, it’s possible for your tire bead to be damaged. Although it’s difficult to damage a tire’s bead, it’s not impossible for it to happen when your wheel is deformed or your tire is scratched. It’s also possible for your tire bead to be damaged during installation if your installer didn’t use the proper tools.  

Whatever the reason, if the bead of a tire is torn, do not try to repair it or fix it on your own. It’s likely that you’ll have to replace the tire entirely. This is because the tire bead is directly tied to your tire maintaining proper air pressure. If there’s an issue with the tire bead, then your tire will leak air and you’ll lose air pressure over time. 

If you’ve recently hit a curb hard or are concerned there’s an issue with your tire bead, have it inspected by a professional. They will be able to verify whether or not your bead was torn or just was knocked loose. It may be the case that your tire just needs to be put reseated back into its housing. 

Doing this on your own is difficult and even dangerous without the proper tools. Professionals also use a lubricant to ensure that there isn’t too much stress on the tire during mounting. Remember that proper tire maintenance can also minimize any risk of your tire bead being damaged.

Photo 24099510 / Car | Zoransimin | Dreamstime.com