the mixer test is done when the bridles shortened after a while , it s used to put the kite back in shape by changing the bridles lenght. thus u can use a flysurfer kites for ages.
i guess you r an english speaker:http://www.flysurfer.ca/Files/File/Support/MixerTestEN.jpg
the walktrough, not complicated, just take your time, get a friend if you r small
it helps .
takes around 15/20mn, u do it when your kite has some strange behaviour (2ns hand kites, stable mixer, 30/35 scessions ), do it on both sides.
i shortened the B 3cm for my ride.
i don t like flysurfer kites much ( well, my speed²) but it s still the best at its job...if i can get rid of the bridles and the mixer test and get the same performance , i ll take it lol