Does anyone know the difference between two yonex shuttlecock series Aerosensa 1,2,3,4,5 and 10,20,30,40,50? Somebody says that no.5 and no.50 are almost the same. Do you know some official explanation? By the way, how about the number at the cap of tube such as 2 or 3? Is it the speed? And what is the appropriate speed should I use? Thanks a lot for you help.
I can only refer to the 10, 20, 30, & 50 (I haven't heard of the others). The higher the number, the higher the quality and price. 10 and 20 use duck feathers; 30 and 50 use goose feathers. I use the 20 occasionally. They are fairly durable, but tend to be too fast.
The only ones I could get my hands on so far are the aerosensa 20. They really, seriously, really suck. They break WAY too easily. I've made a post about aero 20, and also a post about the cap numbers. They're speeds / temperatures. Try to search up the post, someone included a link to the definitions of the numbers.
By keeping them damp, I don't have that problem, but the additional moisture weight contributes to them being fast. They are the only feather birds I've seen sold in a regular sporting goods store--Sport Chalet--so sometimes I have to buy them because I run short of birds and I can't get any others in time for playing.