diff --git a/src/Solver/RubarBE.py b/src/Solver/RubarBE.py
index 26049dfa..6abf719c 100644
--- a/src/Solver/RubarBE.py
+++ b/src/Solver/RubarBE.py
@@ -395,25 +395,59 @@ class Rubar3(CommandLineSolver):
                 lm = len(reach) + 1
                 f.write(f"{lm:>6}\n")
 
-                def get_stricklers_from_rk(rk):
-                    return next(
-                        map(
-                            lambda s: (
-                                s.begin_strickler.medium if version == "2"
-                                else s.begin_strickler.minor
-                            ),
-                            filter(
-                                lambda f: rk in f,
-                                edge.frictions.lst
-                            )
+                lst = list(filter(
+                    lambda f: f.is_full_defined(),
+                    edge.frictions.frictions
+                ))
+
+                rk_min = 9999999.9
+                rk_max = -9999999.9
+                coeff_min = -1.0
+                coeff_max = -1.0
+                for s in lst:  # TODO optimise ?
+                    if s.begin_rk > rk_max:
+                        rk_max = s.begin_rk
+                        coeff_max = s.begin_strickler
+                    if s.begin_rk < rk_min:
+                        rk_min = s.begin_rk
+                        coeff_min = s.begin_strickler
+                    if s.end_rk > rk_max:
+                        rk_max = s.end_rk
+                        coeff_max = s.end_strickler
+                    if s.end_rk < rk_min:
+                        rk_min = s.end_rk
+                        coeff_min = s.end_strickler
+
+                def get_stricklers_from_rk(rk, lst):
+
+                    coeff = None
+                    if rk > rk_max:
+                        coeff = coeff_max
+                    elif rk < rk_min:
+                        coeff = coeff_min
+                    else:
+                        for s in lst:
+                            print(s.begin_rk, s.end_rk)
+                            if (rk >= s.begin_rk and rk <= s.end_rk or
+                                    rk <= s.begin_rk and rk >= s.end_rk):
+                                coeff = s.begin_strickler  # TODO: inerpolate
+                                break
+
+                    # TODO interpolation if rk is not in frictons
+
+                    if coeff is None:
+                        logger.error(
+                            "Study frictions are not fully defined"
                         )
-                    )
+                        return None
+
+                    return coeff.medium if version == "2" else coeff.minor
 
                 ind = 1
                 for mail in edge.reach.inter_profiles_rk():
-                    coef = get_stricklers_from_rk(mail)
-
-                    f.write(f"{ind:>6} {coef:>12.5f}")
+                    coef = get_stricklers_from_rk(mail, lst)
+                    if coeff is not None:
+                        f.write(f"{ind:>6} {coef:>12.5f}")
 
                     ind += 1
                     f.write("\n")