Nylon shuttles are made of a synthetic material (nylon) and often being used by recreational players and people who are just starting the game. They are cheaper compared to feather shuttles and are a lot more durable, making them great for practicing skills and casual play. Feather shuttles are made of natural duck or goose feathers. Goose feathers have thicker bristles than duck feathers and will have better flight quality and durability. Feather shuttles are often used by players who play competitively due to the more natural flight characteristics of a feather shuttle compared to a nylon shuttle. However, many people choose to play with nylon shuttles due to the high cost of feather shuttles and their low durability. So it can depend how seriously you decide to take the game so one might be better for you than another. The structure of feather shuttles are more rigid compared to the soft skirt of the nylon shuttles. Due to this difference in rigidity, nylon shuttles will deform more compared to a feather shuttle when hit. As a result, feather shuttles will have a higher initial speed coming off the bed. Aside from greater initial shuttle speed, the feather shuttle will also decelerate faster due to the higher drag it experiences during its flight and therefore will travel less distance and fall at a steeper angle.
You can distinguish between duck and goose feathers by looking at the feather itself. In goose feathers, you will be able to see an arrangement of lines clearly on the bone of the feather. On the contrary, duck feathers will have less pronounced or nonexistent lines on the bone of the feather. Goose feathers will have a channel or groove in the bone of the feather. Duck feathers will have a shallower groove or none at all.
The shuttle speed is not how fast the shuttle will fly, but how far it will travel in the same amount of time when hit with the same amount of power. For example, a speed 78 shuttle and a speed 79 shuttle will travel different distances when hit with the same stroke.
The weight of the shuttle, feather type, balance point, and weight distribution all factor into the speed of a shuttle. But the most important factor are the type of feathers used in a shuttle. Feather types differ depending on the region of the wing it was taken from. You’ll come to find out the all-round feathers will be used in most top grade feather shuttles as they are superior in flight quality.
You can tell the speed of a shuttle by looking at the tube itself as there is often a number labelled on it. (77, 78, 79, etc..) This system is used by most brands of shuttles except for Yonex which has its own unique numbering system. (3, 4, 5, etc... which is equivalent to 77, 78, 79 respectively). The reason different speeds exist is because a change in the temperature of the environment will affect the distance traveled by the shuttle. As temperature decreases, the air will become more dense meaning you will require a faster shuttle. Many brands of shuttles will have a speed/temperature chart on the tube showing you which speed of shuttle to use for different temperatures. Hey... doesn't this mean that you will require different speeds of shuttles when playing in the winter versus the summer? Yes that is correct, but most people just stick with buying the same speed as most stores only stock a certain speed that is suitable for that location. To solve this problem, you can first test the shuttle by standing at the baseline of the court and hitting it towards the other side. Depending on where the shuttle lands, you can make adjustments to the shuttle to change its speed. This method is known to most as "tipping the shuttle". So there you have it, this should give the info you need to find the right shuttle for your style of play.