Paragliders: Comparing Performance
After reading the first part of the series you might have decided that you are interested in the XC Class. Comparing performance of three of the top contenders in the class, we see how different they are, and how much difference it makes.
Almost everyone wants to know about performance. Can these figures tell us anything?
Advance Iota 26
Nova Mentor 4 S
Skywalk Chili 3 S
Skywalk Chili 3 M
Flat area m2
Proj. area m2
Proj. span m
Line length m
If flown at
Looking at the specs (for a pilot of the same weight) I might expect the Iota to be slightly faster due to the higher wingloading, and the Chili 3 should have better glide due to projected aspect ratio. But the Mentor 4 and Iota have thinner lines so their glide might be just as good. Then there’s the profile shape, wingtip ‘toe angle’ (the angle of the wingtips relative to the whole span of the whole wing i.e. are the wingtips rotated forwards (‘toe-in’), rearwards (‘toe-out’), or straight (neither ‘toe-in’ or ‘toe-out’), relative to the whole span of the wing), line consumption, and even the stitching style and fabric billow that reduces the real area. You can do this kind of guesswork all day. There are too many factors that interact in the complex science of aerodynamics.
But we can test them in the air, right?
Here’s the big problem: you’re unlikely to fly far in still air, and in ‘moving air’ thermals make accurate results impossible. The video showed an Icepeak 6.23 vs an Icepeak 6.23 gliding beside each other. One lost 50m altitude in less than 20 seconds. It doesn’t need to be this dramatic to upset a glide angle comparison: it could be just 0.1m/s sink, which you wouldn’t be able to identify as an air current – you might confuse it for a lack of wing performance.
When comparing performance of the Icepeak 6 vs Mistral 7, gliding close, it looks like the lower class wing has more performance! The longer the glide the more averaging removes inequalities but it’s still possible to glide for 10km along a lifty line and make a worse glider appear to be the better one.
In the video I am 97kg on the Iota 26, Carlo is flying at 94.5 on the Mentor 4 S and John is 109 on Chili 3 L. John’s on a larger size wing, with higher efficiency. I am in a sit-up-and-beg harness, with more drag. Carlo has the lowest wing loading. Already we are not comparing apples with apples.
We are supported by a gas. It only needs to have a few swirls to disrupt the results. Nothing is measuring the unequal movements of the airmass we are gliding through. You’re also only seeing the performance of one unit of a particular make and model, which doesn’t allow for manufacturing variations.
Speeding up one minute of gliding, we can see the start and end position are very similar between that Chili3 and this Iota in that bit of air. No conclusions can be drawn, apart from the fact that that there is very little difference between all current wings within a class. So why the big fuss about performance?
Let’s look at this another way. What kind of difference are you looking for? I’d be interested in a 0.3 difference in glide ratio, so one wing on 10 and the other on 10.3. But in reality, this equates to 3m height gain or 30m ahead after 1km of undisturbed gliding. That’s hard to see when you are constantly moving.
For definitive data you’d need at least 10 glides of longer distance, but unless the air is calm you’ll have too much interference to get repeatable results. When you introduce moving air you cannot separate the disturbance from the performance. What you see is a single data point on a scatter graph of performance.
‘Climb rate tests’ are even more questionable. Minor changes in turn rate and style result in different climb rates. The lift distribution is unequal in most thermals and nothing is measuring the climb rate of the air the wing is being subjected to. The highest agility turn often wins the day, not the best climb rate and this depends on pilot intervention. The wings themselves are so close you’ll go blind trying to see the difference.
Cross country comparisons
On an XC flight, we mostly fly alone, we make thousands of choices and each diversion puts us on a different line. When we do pull up beside another pilot, we don’t know the wing size, wing loading, how much speedbar is being used or how old the wing is. The pilot will be in a difference harness, and he’ll do slightly different things to control his wing. We never get to verify our wing performance in a fair comparison. If you’re not aiming for first place in international competitions, don’t worry about the wing’s performance: if you’re on something current, it is about the same.
Handling is much more interesting, because it governs your ability to put the wing where you want it and to feel hints of where the best lift is.
Stability should concern you too, because it builds your confidence and saves you from your mistakes.
Luckily, these are things which good reviewers can identify fairly fast. At Flybubble we test all of our demo wings to learn about their characters.
The Iota is mostly about ‘handling’, the brakes feel medium and linear but give a quick change of direction. The feedback from the wing is smoothened yet gives you a feeling of being connected with the air. A small criticism we could make is that the Iota’s back risers pull the tip cascade as well, which makes strong wind control tricky unless you reach into the C lines.
The Mentor 4 is all about a ‘secure feel’. The brakes are medium to heavy, they grab at the air and the feedback from the wing is low and dampened. Pilots who prefer a more responsive and energetic wing might find themselves wanting. Out of the three, you’ll be bounced around the least on the Mentor if flying in rough air is your thing.
The Chili 3 has a ‘performance’ character: the brakes feel light and need a wrap because of long travel. The feedback from the wing is moderate, subtle and slightly disconnected, somewhere between the Iota and Mentor. The Chili 3 can get too lively for pilots with slow reactions, it likes to pitch and needs active piloting because it is spicy.
We could add much more. Little details add up to make a big difference in your progression.
If the salesman focuses on the performance of the wing he’s selling and not on you, there’s a good chance you’ll be getting the wrong wing.
The right wing depends so much on the pilot. We don’t produce lists of ‘best’ wings in each class, because they don’t exist until the pilot has been put into the equation. We need to speak to you so we can match the wing with your unique situation.
Don’t be misled by a video showing one data point on a scatter graph of performance. Talk to expert pilots with experience on the wings you’re considering. There’s more to wing comparisons than straight line gliding. There’s more to becoming a top pilot than buying a wing.
We hope this article and accompanying video (see below) help you understand comparing the performance of wings.
If you need good advice based on a broad range of brands, come on over to our website and see what we have to offer. We are expert at matching pilots with the right gear.
Check out the current range of wonderful wings we have to offer.
How to Choose the Right Paraglider Part Two: Comparing Performance video
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Paragliders: Weight Ranges & Wing Loading
The best glider in the world is no use to you if it isn’t the correct size for your flying weight! In this third article of our Choose The Right Paraglider series, we look at paraglider weight ranges and the effect that wing loading has on performance, stability and handling, and how to decide what’s best for you.
First, join us in an investigation. Stuff everything into your glider backpack, exactly as you would walk up the hill, with your extra jacket and flying boots. Then stand on the scale! More than you thought, huh?
> Your all-up / total flying weight includes *everything* you carry up the hill—everything that goes up into the air—including the wing, and you!
Your flying equipment and all the extras usually adds 14-20kg to your clothed weight (depending on the weight of your kit and how much other stuff you carry).
What does it matter? Well, they say that by loading a given wing with more weight you will increase all flying speeds, increase stability and get more responsive handling. But is it really true?
The effect of weight on speed
Top speed is a safety factor. But, as we shall see, you cannot change this much with either ballast or downsizing, and within a given class the speeds are very similar.
We tested the effect of adding 20kg to a pilot’s flying weight on an EN D wing with a weight range of 85-105kg, flying directly upwind and downwind and averaging the GPS speeds achieved.
> Big Bad Ballast. Don’t try this at home, kids!
Flying at 85kg: trim speed = 33.3km/h, full bar = 47.2km/h
Flying at 105kg: trim speed = 36.3km/h, full bar = 52.8km/h
Speeds also vary greatly depending on temperature, pressure and altitude. We have recorded 39km/h at trim and 59km/h on full bar many times, but the day of our tests was a ‘slow’ one – 15 degrees, 250m ASL, 1013hPa. As we are investigating relative changes it doesn’t matter.
Adding 20kg of ballast increased trim speed by 3km/h and top speed by 5.6km/h, or +10% speed for +20% weight. But 4kg is the practical limit of ballast – any more is cumbersome in your harness and upsets your balance. In these conditions, adding a big ballast bag of 4kg would increase trim speed by no more than 0.8km/h and top speed by no more than 1.3km/h or 3%.
> Simple speed test using GPS speeds.
(We’ve been generous here as it’s not entirely linear: as you add more weight you get less of a benefit in speed as the drag increases at the square of the change in velocity. On earlier tests on a tandem, adding 70kg (a passenger) increased trim speed by only 7km/h, not 10.5km/h).
If you think a 1km/h advantage is going to win you a competition, remember that there is a sink rate penalty when carrying ballast, which will slow you down as more thermaling will be needed. Being slightly behind but faster on glides might be a strategic advantage, but either way it’s an incredibly marginal benefit.
For most pilots, adding ballast is a waste of energy. It will not make a strong-wind day flyable and it makes your carry-up a nightmare.
What about moving down a size onto a smaller wing? This can increase your speed slightly more than 4kg of ballast, theoretically by +1.5km/h at trim and +2.5km/h flat out.
> What about moving down a size of wing?
Taking a 95kg pilot off (eg) a 27m wing (90-115kg) and putting him on a 25m (75-100kg) has the equivalent effect on wing loading of adding 7kg ballast.
It might seem that you are much higher up in the weight range, but wings are often designed with reduced wing loading as they get smaller. Small wings are usually less efficient than larger ones and the speed change is likely to be lower than expected, and the glide performance might be degraded too. We don’t recommend chasing top speed by downsizing. There are more important factors to consider.
Weight and safety
We’d recommend being well-loaded on your wing to reduce the frequency of collapses, increase control authority and increase flying speeds. A loaded wing becomes slightly more collapse-resistant, but it will have more energy if it does collapse and your height loss might be more severe. But as long as you’re within the quoted weight range, all collapses are roughly within the norms and you’ll be able to handle them regardless of your weight – if you’ve already chosen the right paraglider class. At full speed on bar the wing deformation is worse on a loaded wing due to the force of air striking the wing making it pucker. There is a limit to how fast these things can go!
> The safety of the wing is determined primarily by the wing design.
The safety of the wing is determined primarily by the wing design. What you can influence by changing the wing loading (within the certified weight range) will have little effect in comparison to the passive safety of the type of wing you choose.
Weight and performance
Optimum performance is found in a broad range. In the morning you need to be light; at peak thermal time you need to be heavy; then in the late afternoon light again for extended flying in weak conditions. So nobody is ever truly optimised.
There is a broad sweet spot for all wings, which is usually somewhere around 50-75% of the quoted weight range, although this varies depending on the manufacturer.
> Optimum performance is found in a broad range.
If you fly in strong conditions (wind, thermals, tricky launches) you’ll get a slight advantage by choosing a wing where you’ll be heavily loaded. If you fly in light conditions (soaring the coast, floating downwind on flatland XCs, easy launches) you’ll get a slight advantage by choosing a wing where you’re lightly loaded.
Weight and handling
An overloaded wing feels ‘hard’ and doesn’t turn well (banks too much, loses height, feels like it is ‘grinding’ around the turn). An underloaded wing feels wobbly, collapses more often in a soft, floppy kind of way and doesn’t turn that well either (sluggish handling, difficult to turn back in when thermals push you out).
> It’s best to choose a wing where you are well-placed in the weight range in the first place.
There is an optimum range or sweet spot for ‘best handling’, often around 50-80% of the certified weight range (this too varies from model to model, even size to size, and also depends on personal preference and other factors). If you’re outside of the weight range, the amount of ballast you’d need to carry before your wing handling changes significantly is impractical – and what you’ll feel most is the counterbalancing effect of a weight below your body, stabilising the harness and making turning less agile.
All in all, you must make an effort to choose a wing where you are well-placed in the weight range in the first place. If you’re outside the weight range altogether the wing will still fly. The manufacturer didn’t try to certify it at this weight because it is not an optimal loading to fly the wing at, and would probably result in a higher certification class (eg an EN B becoming an EN C). At this extreme point of low or high wing loading you will likely begin to notice a handling change.
Every designer has their own idea of the perfect wing loading, which changes depending on their objective for the wing. If they want their target group of pilots to be impressed with the climb rate they make it larger; if they want it to get a reputation as nimble and fast they make it smaller. As the aspect ratio of the wing increases, so does the ideal wing loading because the wing is more efficient. This makes it hard to know what your ideal wing loading should be.
> It can be hard to know what your ideal wing loading should be.
Manufacturers usually offer 20kg weight ranges, but the design/ manufacture/ testing/ refining/ certification process makes larger weight ranges and smaller overlaps more economical. And you might like a wing design but be in an uncomfortable place in the overlap between sizes.
As explained above, we don’t recommend ballast. We recommend getting the right wing. Be prepared to look at other brands to achieve this. This article is intended to guide pilots to choose the right wing at any time from any manufacturer’s range, which is why we’ve avoided using any model names.
When choosing your next paraglider, narrow it down to those that put you in the right place in the weight range to start with, and identify the ones that give you a wing loading that suits your flying environment. If you’re lucky you can get a trial flight on your size so you can feel the handling at its best.
Weight ranges explained
Some pilots may be confused by manufacturer’s quoted weight ranges, and these can sometimes be misleading. In short, almost all paragliders have an officially certified weight range (CWR) that accords with their certification. The glider has been tested at the extremes of this range and found to have acceptable characteristics for the EN/LTF certification level.
> In light conditions you’ll get a slight advantage by choosing a wing where you’re lightly loaded. But in strong conditions the advantage is with a pilot flying in the upper end of the weight range.
Some paraglider manufacturers also state a recommended weight range (RWR) within the boundaries of the CWR. This means the manufacturer knows the wing flies at its best within the recommended range, even if the certificated range is wider.
Some manufacturers also state an extended weight range (EWR), often certificated at a higher rating. For example a wing may be certificated at EN/LTF A wing within its CWR (and thus its RWR too), but be an EN/LTF B or C at the limits of the EWR.
Weight ranges tend to be narrower the smaller the wing. A 22m wing may have a CWR of 50-70kg (a 20kg range), while the 31m size of the same wing may have a CWR of 100-130kg (a 30kg range). In this case the recommended weight range (RWR) will also increase with glider size.
Weight ranges tend to be narrower as the performance (and certification class) of the wing rises. An EN/LTF A wing could have a tolerant CWR of 75-100kg, while an EN/LTF D wing may have a much narrower CWR of 85-97kg.
Some paragliders with EN/LTF certification are also certified at higher weights for paramotoring (DGAC certification). These are self-certified by the manufacturer; such testing as is involved does not include recoveries from extreme flight conditions, or tests repeated at various trimmer settings. The BHPA doesn’t regard a DGAC declaration as an acceptable independent verification of a wing’s safety.
Finally, some manufacturers have a tendency to get their wings certified for the largest possible range of weights to maximise the potential market. In reality their wings only fly well within a much smaller optimum weight range. A pilot can end up with a wing that is very much the wrong size for them despite being within the official certified weight range.
How to decide
When choosing your next paraglider, narrow it down to those that put you in the right place in the weight range to start with and identify the ones that give you a wing loading that suits your flying environment. If you’re lucky, you can get a trial flight on your size so you can feel the handling at its best.
> Nancy at Flybubble on the perfect size wing, giving ideal wing loading!
We hope this article and accompanying video (see below) help shed light on paraglider weight ranges and wing loading.
Flybubble offers a comprehensive range of wings. We’d be happy to help you make the right choice.
How to Choose the Right Paraglider Part Three: Weight Ranges video
We take a closer look at weight ranges in our related article Paraglider weight ranges: the numbers.
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Paraglider weight ranges: the numbers
The best glider in the world is no use to you if it isn’t the right size for you. We explain how to navigate the different manufacturers’ weight divisions.
In our Paragliders: Weight Ranges & Wing Loading article (part of our Choose The Right Paraglider series) we looked closely at how wing loading affected speed, safety, handling and performance. Now we delve into the numbers to help you choose the right size wing for your requirements.
A glider’s weight range is one of the most important considerations when choosing a wing. However, to be able to make a correct and well-informed choice there are many other factors to consider.
The object of the exercise is to get the best glider for you. Whilst brand loyalty is a laudable emotion, the way a manufacturer decides their sizes – and your own life changes – can put you in the wrong place in the weight ranges for your favourite brand.
> If you fly mainly from smaller hills, most manufacturers advise you to be in the middle third of the weight range.
Primary considerations include the wing’s passive safety, pilot demands in active air and the desired use: simple fly-downs, soaring, thermaling, XC, hike-and-fly or high wind soaring. Also, will you fly mostly in the mountains, hills or flatlands? More on topography and flying conditions later.
Other common aspects which may well affect a buyer’s decision include handling, feeling, performance, glider weight, durability and pack volume, to name but a few. Mostly it’s not just down to one factor or even a few; pilots often weigh up the main strengths and weaknesses of each wing to come up with its ‘sum value’ to them. The relative importance of each factor will vary significantly between individuals – everybody has their personal requirements and preferences!
The most popular gliders (mostly EN A and EN B) tend to have the largest number of sizes and the biggest overlaps in their weight ranges, allowing for a better size choice. As you go up the certification categories – with increasing pilot demands and decreasing sales – there tend to be fewer sizes, with less overlap between them.
Being in the right place of the weight range tends to be more critical the hotter the wing gets; this is why pilots flying hot ships tend to carry ballast and/or favour heavy competition harnesses. But even with less-demanding wings, it’s always important to be in a good place in the weight range of any paraglider.
> If you mainly fly in Alpine conditions you may find that nearer the top end of the weight range is best; the ability to turn hard into strong climbs outweigh the very small penalties from a slight loss of sink rate.
Given that you want to be in a certain area of the weight range, you should look at models from several different brands. This is one of the main reasons we offer several carefully selected top brands of wings, and one of the key aspects we cover during our Flybubble MATCH service, ensuring you end up with the best wing for you as an individual. This article is intended to give some insight into making a short list of ‘candidate’ wings which may work for you.
Looking at example paraglider weight ranges
What do we mean by this? Let’s look at the weight ranges (in kilograms) for each of the sizes of a theoretical paraglider model, based on typical actual weight ranges from the main brands.
XS 55-75kg, S 65-85kg, MS 75-95kg, ML 90-110kg, L 105-130kg.
You know that when you carry the minimum required, for shorter flights in weaker and milder conditions, or with more walking involved, you’re probably around 110kg all-up. For longer, more demanding flights and conditions, with more water, supplementary clothing and other paraphernalia, your all-up weight rises to around 112kg.If your all-up flying weight varies from 110 to 112 kg, you might feel that you’re not well-catered for by this particular model.
This means that for this particular model you have the choice of being either right at the very top of the certified weight range of the 90-110kg size, or even over this (112kg), or near the bottom of the weight range of the 105-130kg size.
As well as how this will affect the wing’s stability, handling, airspeed, sink rate etc (see our article Paragliders: Weight Ranges & Wing Loading also referenced above) if you fly a wing loaded outside the official certified weight range then the wing is no longer certified, and would likely fail it’s certification. In a competition weigh-in, you’d be disqualified.
For this reason, having first considered the various other primary factors e.g. safety, pilot demands, desired use, etc, you can further reduce your list of next wings to consider by looking at the weight ranges of the various candidate models.
To illustrate, let’s consider a few examples. In our example above, if your all-up weight varied from 110-112 kg then, depending on various factors, you might look for a model with a weight range of 95-115kg, or 100-120kg. If your all-up weight range varied around 95-96 kg, you might look for a model with an 80-100kg or 85-105kg size. If your all-up weight varied around 89-92kg, you might well look at the 75-95kg size of the example model tabled above.
Now, let’s look at the philosophy of where you want to be in the weight range. There is a lot of conflicting advice on the Internet. The best place to get advice on weight ranges and where to be in them is from the manufacturer since they have the ultimate interest in you being happy with your glider and becoming a repeat customer. However, there is an added dimension in that any advice needs to be tailored to you as an individual, taking into account how often you fly, your ability, experience and future aspirations.
As we go up the weight range, the trim (and other key speeds) increase, and the sink rate at those speeds gets worse. The glide angle in still air remains the same. The change in sink rate and speed is likely not as much as you might expect¹. To give an idea, the graph below shows three polar curves for the same wing (in this case a glider / sailplane) at different wing loadings: 28, 35 and 38 kg per m2 (much higher than a paraglider, usually).
As the wing loading increases, the glider will become more responsive and agile, but will also react more quickly to any incidents, and the reaction will be more serious. Quoting Advance Paragliders: “Higher wing loadings mean more demanding flight characteristics and handling.” These effects are usually not huge, but are noticeable and significant.
The table below provides an illustration of wing size loading against pilot demands (and recommended pilot level) for the Advance PI 3, as an example.
Another example, the table below illustrates wing size loading against wing dynamics and pilot demands for the Phi ALLEGRO:
So long as you stay within the given certified weight range, your glider remains within the EN category it has been allocated. This, and avoiding disqualification in fun competitions, where the only weight criterion is all up weight, is why you should remain within your glider’s certified weight range.
The differences between the top end of a smaller glider and bottom end of the next one up the size range are easily noticeable when you have a few hours under your belt, but the odd two or three kilograms will be difficult to detect for most pilots on most wings.
Topography & flying conditions
If you mainly fly in alpine conditions, or anywhere there are strong climbs, you may find that nearer or even at the top end of the weight range is best for you. Here, the ability to turn hard into strong climbs, and any other advantages from higher wing loading outweigh the very small penalties from a slight loss of sink rate. Some feel that the wing is more pressurised and resists deflation better.
Similarly if you mainly fly at breezy coastal sites, you will likely prefer to be top-loaded on your wing. Some pilots, often flying in windy conditions, even prefer to fly over the top of the wing’s given weight range. However this means they are flying the wing outside its design envelope. They should consider wings specifically designed with higher-wind soaring in mind like some mini wings, provided they have the skills for them.
If however you fly mainly from smaller hills, or in the flatlands, and wish to stay up in less strong conditions with decent height gains, most manufacturers advise to be in the middle third of the weight range. Here, thermals are not so powerful, and the ability to hang or climb in weak lift becomes more important. It’s the ability of the canopy to float along in very light lift that becomes more of an asset.
Whilst it’s important to consider the numbers, it’s also important not to dwell on them too much. Getting a glider that is well suited to your ability, experience, personal preferences and aspirations is the main point of the exercise. Wherever you fly in the weight range involves slight compromises, but it’s important to get these to work in your favour. It can’t be overemphasised that this is a very individual thing. Take care not to let others confuse you by projecting their personal preferences onto you.
Final short list?
All these points should help you narrow down the final list of the wings you’re interested in. Then you can approach your preferred dealer to make your final choice and, if appropriate, arrange test flights on their demos. For the inexperienced pilot, detailed advice may be more important than demos, but that needs to be decided as part of a detailed discussion with each individual pilot.
If you’d like expert advice on choosing your new wing, then it’s worth looking at our MATCH Service, which will give you a one-stop-shop for drawing up the list, based on all of your requirements and our wealth of knowledge and many years of experience, arranging demos as required, and ordering the wing you want to buy. We also offer generous part-exchange and package deals, if you’re looking to purchase more than one main item of kit.
¹ The trim speed will increase as the square root of the ratio of the weights. So, if the trim speed for a 100-120kg wing is 36km/h at 100kg, at 120kg it will have increased by the square root of 1.2, as 120 = 100 x 1.2 The square root of 1.2 is 1.1, so the difference between the bottom of the weight range and the top is 10%, so the actual figure is 39.4km/h
The sink rate will behave in much the same way, so if the best sink rate is 1.1m/s at 100kg, then at 120kg it will be 1.2m/s.
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