There are three bodies in Europe that test Paragliders and their stability in the gambit of categories. When the DHV, LTF or EN test a wing, they rate each glider with an “all up” weight range. What all up represents is the full payload that the wing will support during flight. This weight includes the weight of the wing, harness, clothing and all accessories you will fly with. The easiest way to figure your all up weight is to stand on a scale with all of your flying gear in you wing’s rucksack. A normal paraglider with full sized reserve and harness and other accessories will often weight about 45 lbs / 20 kilos. With the very light weight harnesses and wings that are now becoming available, the weight of gear can be reduced to about 25 lbs / 11 kilos. So, when sizing wings, it is important to know how much your all up weight is.
Some companies use the terms XS – XL to define the wing sizes. Others just use a number which relates to the size in some way. All companies do not size their wings the same. The weight range of a wing is stipulated by the manufacturer. The testing body will then run their tests with minimum and maximum weights from the specified range. One wing might be sent in that is 28 meters projected and 30 meters flat by one company and they might request it tested for 90 – 115 kilos, whereas another company could have a wing with the exact same size and it could be certified for 80 – 100 kilos.
Compare apples to apples
It is important to objectify the sizing of wings by using the sail area and aspect ratio of each paraglider. Some companies hedge the testing to help them pass at the lowest rating. This frequently leads to stipulating a lower weight range than is a true, “best fit” for the middle of the weight range.
The tests which are more difficult to pass (achieve the desired lower ratings) are often the ones with that include the use of the speed bar. Reactions to these “accelerated” tasks tend to increase with a heavier load. So, this is the reason that a lighter all up range might hedge a wing’s passing at the manufacturer’s desired level. If you are looking at more than one wing, you can get a better feel for their sizing to weight range by comparing a couple wings. This can be done with a great web site that has a wing comparison tool. The site is called para2000.org. The comparison tool will allow you to look up the wings and compare their specifications.
The measures used for weight ranges are done in Kilos. A kilo is very close to 2.2 pounds. The simplest way to convert Lbs to Kilos is the following:
Converting Kilos to Pounds:
(Kilos x 2) + 10% = Pounds
For example (85 Kilos x 2) = 170 + (.1 x 170= 17) = 187 Pounds
Remember, the all up weight includes all of the gear.
So, for a wing that is rated for 85 – 105 kilos, you could convert to pounds and come up with an all up range for that glider between 187 and 231 lbs. This wing is therefore rated for (assuming an avg. 45 lbs for gear included in the all up weight) a pilot 142 – 186 lbs.
The other way to do this is perhaps even easier. Just use your own naked weight, convert to kilos and add 21 kilos for gear (assuming you have a standard weight harness and reserve).
Converting Pounds to Kilos:
(Pounds – 10%)/2 = Kilos
For example (160 Pounds – 10%) = 144 / 2 = 72 Kilos
The weight of the gear must now be added. For this sample, we can use 20 kilos for the sum of (Wing, Harness, Clothing and Accessories). 72 + 20 kilos makes for 92 kilos flying weight. If you are looking at a lightweight wing and a light harness you would adjust the gear figure down accordingly.
Weight Range Differences:
Instructors often adjust the size of wing to have the pilots heavier in the weight range. With the stronger winds that are common in the Bay Area, having extra speed is a very important part of safety. Being light on a wing is not as good a trade off when compared to having the ability to fly a bit faster when the need is there.
Due to the aerodynamics, there are sizing rules that affect how sink rate and speed relate to the size of wing. The pilots that get the best sink rate performance and have the most limited top speeds are the small sized ones. Conversely, pilots in the larger weight ranges have the higher top speeds but will not have as good of a sink rate.
It is more important with smaller pilots to be in the upper end of a paraglider’s weight range. Larger pilots flying at the middle of the range will usually be faster than a small pilot flying at the top of the specified weight range. This is based on scaling of paragliders and the related increase in drag percentage when wing sizes are reduced for smaller pilots. On light lift days, the small pilots will gain the benefit of this trade off with better sink rate. They will soar higher and get up in ridge lift better in very light conditions. However, on stronger wind days, top speed and penetration will be much more of a safety concern..
Larger pilots (that will fly L or XL size wings) can fit wings from the middle to the upper end of the weight range. There is a bit more flex here because penetration is not nearly as limited if the pilot chooses to go in the middle of the weight range. A small pilot on a small or extra small wing flying in the middle of the weight range would have very low top speeds.
There are some general rules that relate to being heavy or small on a wing. When a wing is more lightly loaded, the reactions to collapses and flying events will happen slower and with less severity. With higher loading on the wings, there will be a higher pressurization of the wing, but more dramatic reactions. With heavier loading, collapses will happen less frequently, but when they do occur, the reaction will be stronger than on a lighter loaded wing.
The best approach for this is to learn how to compare the wing sizes and work with your instructor to match the characteristics you want from a wing. The above information should help you to understand some of the goals and reasons for careful sizing of your paraglider.