Unfortunately there is no hard and fast rule when choosing a wing, your choice needs to be based on collected knowledge and this is gained by asking questions of other pilots and the manufacturers. Don’t fall into the trap of talking to one trader who only sells one make of wing, they will always claim theirs is the best but it may not be the case. In addition there are many paraglider outlets selling wings having never flown them. They are simply middlemen passing on product and using the manufacturers write up as their basis to talk about the wings. I must stress this is not the case for all traders!
For this reason I will be putting up a Q & A page on this site. If you have a question just email the site and I will put up the info for others to read. For the time being here is a general overview of speedwings.
Risers
Two riser system: This is a skydiving setup and was the main style of riser when the sport began in the Alps 3-4 years ago. It is now found more on speedwings used for ski launching. The two riser system generally means the aerofoil section of the wing will be distorted when the trims are used resulting in broken airflow over the wing and hence poor glide performance. This is fine as that’s what is needed to following the contours of a mountain. Only having two risers also considerably simplifies the line layout on the wing.
Three riser system: Three risers allows the same range of trim adjustment as on a two riser system but over the whole range the shape of the aerofoil can be better controlled with less distortion. The benefit of this is that for a given wing loading and shape the same speed can be achieved but with improved glide angle. This allows a pilot to better mach the glide of the wing to the slope and allows them to flow shallower slopes that would be un-flyable on a lower performing two-riser wing. There are speedwings available that offer very good glide but this can sometimes be a bad thing. Some wings glide so well that the pilot will find himself flying out away from the hill, even when flying aggressively with steeply banked, linked turns.
Trimmers
Rear trims: Generally a three riser system will have trims on the rear only. When the trims are pulled on they reduce the angle of attack and the wing is on its slowest speed setting and best glide setting. Letting off the rear trim caused the rear riser to increase in length putting the wing in a more nose down attitude. This gives you more speed, more dive from turns and reduces your glide. The centre riser on the three riser system floats and its length adjust automatically depending on the trim setting.
Front and rear trims: These are found on a two-riser system. With this system the range of adjustment on the trim tabs is about half that of the three-riser trim but as there are front and rear trims the overall range is roughly the same.
No trims: This is more the case with adapted skydiving wings or purpose made speedflying wings from skydiving manufacturers. These wings are trimmed with a nose down attitude. The speed and glide angle is controlled with the brakes or rear risers.
Harness
Skydiver style harness with shoulder hangs points, or paraglider style harness with low hang points? This is a point of preference with no real right or wrong although there are differences.
Skydiver style harness, high hang points:
Good points-
Safer upright body position.
Feels natural for skydivers.
Reduced weight shift input, more stable in rough air.
Bad points-
Harnesses can be comparatively expensive.
Ground handling and launching in strong winds harder due to being pulled at shoulder level.
Separate rucksack needed to pack harness and wing into.
Paraglider style harness, low hang points:
Good points-
More comfortable seated positions with adjustment to move pilot upright.
Easier ground handling and launching.
More weight shift to influence wing aggressively (good for advanced pilots).
Usually reversible into good size rucksack.
More natural for PGer pilots.
Bad points-
Potential to be seated on landing if pilot is inexperienced.
Size
There is more to picking a wing than just its size. As with paragliders, two wings of the same size and loading can have totally different characteristics. One may be suitable for a beginner while the other for advanced pilots only. Currently there is no rating system so this is not as easy to work out as it should be. First of all you need to be clear about your ability and canopy experience. Secondly you need to be clear what you want the wing for. Low, fast flights following the terrain and dropping out of the sky on turns? Or something with better glide allowing you to fly shallower slopes.
You must be comfortable with your harness as you don’t want to be thinking about it at any phase of a run. There is no right or wrong only what is right for the individual.