i disagree... you should not change anything.
if yr flex is 48,then the speeds are calculated precisely to take off with yr weight. be it v1 vr or v2. it has been calculated for the flex thrust.
now if u mix them up... like johnny says...there will be a chance the v1 will be higher than v2.
remember the speeds are calculated via thrust input. and if u just use yr v1 from the flex,and vr v2 from the std speed cards... when u reach vr,u might not have enough speed for lift because remember...you are still on flex thrust.
it may be very complicating to you,but just sit back,have a ciggy,and think about it alright??
