Area or portability? The design philosophy behind the size and number of ribs in a folding umbrella.

August is a month of intense heat, and parasols have become the most common accessory for summer outings. Folding parasols that fit easily into bags are especially popular, but when it comes to choosing one, many people are unsure which one is best for them, as they come in a variety of lengths (50cm, 60cm) and numbers of ribs (5, 6, or 8).

In fact, it is the combination of the length and number of ribs that determines the comfort of a folding umbrella. In this article, we will explain the criteria for choosing the right size from a professional's perspective, assuming that you will also be using the umbrella in rainy weather.

Modern size based on a 55cm rib

The "x cm" number you see when labeling a parasol size refers to the length of the ribs that radiate from the center of the umbrella. In the past, a compact 50 cm rib was the standard for folding parasols, but with the recent heatwaves and changing needs for people wanting to be more securely covered even in rainy weather, it is now smart to think of 55 cm as the standard size.

• Approximately 50cm (compact) : Storage is the top priority. A maneuverable size that is easy to handle even in a crowd.

• 55cm (standard) : Excellent balance of coverage and portability.

• Around 60cm (large) : Protects your shoulders and backpack, providing exceptional peace of mind in rainy weather.

The length of the ribs directly affects the diameter when opened. If you want to thoroughly protect yourself from the sun or want to walk around without getting wet on rainy days, then the 60cm size is the right choice. On the other hand, if you want to keep it in a small bag at all times, then the lightness of the 50cm size is the better choice.

The role of "number of bones" in determining area and rigidity

Another thing to pay attention to, along with the size, is the number of ribs that support the folding structure. This determines the umbrella's shape and the effective coverage area.

Generally, even if the ribs are the same length, the more ribs there are, the closer the umbrella shape becomes to a perfect circle and the larger the area. Let's use an umbrella with 55cm ribs as an example to compare the difference in area (theoretical values) depending on the number of ribs.

• Five-rib structure : This structure is designed to be as lightweight as possible. Because it is close to a regular pentagon, the surface area is approximately 8.5% smaller than that of a six-rib structure.

• 6-rib : The mainstream folding umbrella. It has about 9% more surface area than a 5-rib umbrella, providing a good balance of portability and coverage.

• 8-rib : A structure closer to a perfect circle. Compared to 6-rib, the area is approximately 9% larger .

In other words, even if the dimensions are both "55cm," there is a difference of about 1.2 times (about 19%) in area between 5-rib and 8-rib tent. If you are looking for more shade and stability against wind, the 8-rib option is a very reasonable choice.

The best solution for your "summer movement patterns"

The ideal one is within your lifestyle.

If you travel mostly by train or bus, a lightweight 50cm or 5-rib model will be more considerate of those around you. If you spend a lot of time walking for work or commuting, a 60cm or 8-rib model will maximize shade and dramatically reduce fatigue.

Not just a sunshade, but a partner to help you get through the harsh summer. By understanding the intention behind the size and number of folding umbrellas, you will surely be able to find the "right answer" for you.