thank you all, for the quick answer,
just today I tried to fix all the lines with a rope to a tree,
I gained a good result for the 9 bar,
I set the back lines at the last node in both pigtail,
then I pulled the backlines, now it seems the back are long like
the job for the 11 is not yet concluded, because I followed the same procedure,
last nodes in pigtail then i fixed all the lines at a big tree then I pulled, but not enought
to have the front same lenght as the back, the chicken loop did not enter perfectly in the
bar hole...it miss I think 4 cm more, I don't know if I could extent more the back...maybe could be
better to remove some cm from the front in some way?!?!?
I`d go extending back lines if I were you. Adding lenght to the bar pigtails looks much easier .