You're descending on rough gravel, hit a rock you didn't see, and a few seconds later you're pulled over on the side of the road, wondering whether it's going to be a five-minute fix or a long walk home. It's a situation almost every cyclist knows all too well: the infamous pinch flat.

A pinch flat — sometimes called a "snakebite" — happens when a hard impact compresses the tire casing hard enough against the rim edge to cut it. On a tubed setup, the tube is pinched between the tire and the rim, leaving the two signature holes side by side. On a tubeless setup, the same impact can cut the casing itself. Either way, you end up with a soft, unrideable tire, often at the worst possible moment.

What is a reinforced wide bead on a gravel rim?

Rim bead width refers to the width of the supporting surface at the rim's outer edge where the tire bead sits. Internal rim width, by comparison, measures the distance between the two bead seats. Bead width is a less visible part of rim design. Its importance becomes easier to understand when you consider what happens during a hard impact or under demanding riding conditions.

How brands approach rim-edge protection?

Roval associates its FlatStop bead with pinch-flat protection, describing the 5.38mm figure as the widest in the gravel market, and states that the design — carried over from its mountain bike wheels — requires about 91% more force to cause a flat than the previous Terra CLX II. (The lighter Terra CLX III uses a 4.86mm version of the same hooked profile.)

Reserve's hollow-hook design removes excess material inside the rim while reinforcing the critical wear zones, aiming to deliver pinch-flat protection without a weight penalty.

How can Wider Rim Edge Help Against Pinch Flats?

1.Spread the impact. A wider supporting surface gives the compressed tire casing a broader area to bear against. Depending on the rim's overall geometry and construction, this can help distribute loads and improve resistance to impact-related casing damage.
2.Protect the rim itself. The rim edge is exposed to direct impact during rough riding. Reinforcement around the bead area adds material and structural support where impacts may occur — particularly relevant on carbon rims.
3.Make lower pressures viable. Fewer pinch flats at a given pressure means riders can run the lower pressures that improve grip, comfort, and rolling efficiency on gravel.

What ORNAN's reinforced wide bead features?
The Pro-SA25 reinforced wide bead is a 700C carbon gravel rim built around a 5.5mm reinforced wide bead — at the wide end of the published range discussed above. The rim is hooked and tubeless-ready, with a 25mm internal width and a 36mm external width, a recommended tire range of 35C–70C, and four depth options: 35, 40, 45, and 50mm. Multiple carbon layup options are available.