Why are feather shuttles often perceived as ‘heavy’ by players who are only used to nylon shuttles?

One of the most confusing things in initial trials of Bird2 was the huge difference in preferred and also perceived speed.  Trialling was initially done with county standard or feather club players and the speed was set to their preference. When we started to test in larger numbers with nylon clubs the early production was thought to be too fast.  Measuring ‘medium’ speed Yonex 370s and 300s and others they averaged slow to very slow in speed tests. The assumption is that nylon club players like a good rally and the slower shuttle gives a bit more control around the net where the standard nylon design is less controllable off the racket face.  Feather users expect to be able to clear from back to back without straining every sinew to do so, so feathers shuttles are very carefully measured and are offered in a bigger range of speeds but on the whole faster than nylons in terms of distance travelled.

However there are many different aspects to speed.  Speed is a function of shape, structure, spin and weight. The standard nylon design is inherently slower so they tend to be heavier than feathers as they move slower through the air. But, in reverse, when playing a tight net shot they travel faster, as they bleed air more readily and therefore travel further upwards before turning over. This leads to a higher bounce (less control) and slower ‘righting’. It also explains the odd description of ‘heavy’ from players who have not used feathers before. Feathers form an almost complete baffle and cup more air when in reverse and, along with some other unique characteristics of feathers, this means a slight hysteresis on contact and an increase in perceived weight. This means that they travel slower, bounce lower and right more quickly. Even with Bird2 shuttles of the same actual weight as standard nylons they were sometimes referred to as feeling heavy as they cup more air similar to feather shuttle. The new production tools will produce a slightly lighter shuttle but with the same ability to cup more air.