diff --git a/src/collision/collision_regime.f90 b/src/collision/collision_regime.f90
index 89fdeb269..94079e388 100644
--- a/src/collision/collision_regime.f90
+++ b/src/collision/collision_regime.f90
@@ -61,6 +61,8 @@ module subroutine collision_regime_impactors(self, system, param)
                                          x1_si(:), x2_si(:), v1_si(:), v2_si(:), density_si(jtarg), density_si(jproj), &
                                          min_mfrag_si, impactors%regime, mlr, mslr, impactors%Qloss)
 
+         if (allocated(impactors%mass_dist)) deallocate(impactors%mass_dist)
+         allocate(impactors%mass_dist(3))
          impactors%mass_dist(1) = min(max(mlr, 0.0_DP), mtot)
          impactors%mass_dist(2) = min(max(mslr, 0.0_DP), mtot)
          impactors%mass_dist(3) = min(max(mtot - mlr - mslr, 0.0_DP), mtot)
diff --git a/src/collision/collision_util.f90 b/src/collision/collision_util.f90
index 844bb8cca..68412cfc5 100644
--- a/src/collision/collision_util.f90
+++ b/src/collision/collision_util.f90
@@ -413,8 +413,8 @@ module subroutine collision_util_reset_system(self, param)
       self%pe(:) = 0.0_DP
       self%Etot(:) = 0.0_DP
 
-      call self%impactors%reset()
-      call self%fragments%setup(0, param)
+      if (allocated(self%impactors)) call self%impactors%reset()
+      if (allocated(self%fragments)) call self%fragments%setup(0, param)
 
       return
    end subroutine collision_util_reset_system
diff --git a/src/fraggle/fraggle_set.f90 b/src/fraggle/fraggle_set.f90
index 7c405db90..b0cfdf951 100644
--- a/src/fraggle/fraggle_set.f90
+++ b/src/fraggle/fraggle_set.f90
@@ -52,7 +52,7 @@ module subroutine fraggle_set_mass_dist(self, param)
       integer(I4B)              :: i, jproj, jtarg, nfrag, istart
       real(DP), dimension(2)    :: volume
       real(DP), dimension(NDIM) :: Ip_avg
-      real(DP) :: mfrag, mremaining, min_mfrag
+      real(DP) :: mfrag, mremaining, min_mfrag, mtot
       real(DP), parameter :: BETA = 2.85_DP
       integer(I4B), parameter :: NFRAGMAX = 100  !! Maximum number of fragments that can be generated
       integer(I4B), parameter :: NFRAGMIN = 7 !! Minimum number of fragments that can be generated (set by the fraggle_generate algorithm for constraining momentum and energy)
@@ -66,7 +66,9 @@ module subroutine fraggle_set_mass_dist(self, param)
       class is (fraggle_fragments)
          ! Get mass weighted mean of Ip and density
          volume(1:2) = 4._DP / 3._DP * PI * impactors%radius(1:2)**3
-         Ip_avg(:) = (impactors%mass(1) * impactors%Ip(:,1) + impactors%mass(2) * impactors%Ip(:,2)) / fragments%mtot
+         mtot = sum(impactors%mass(:))
+         Ip_avg(:) = (impactors%mass(1) * impactors%Ip(:,1) + impactors%mass(2) * impactors%Ip(:,2)) / mtot
+
          if (impactors%mass(1) > impactors%mass(2)) then
             jtarg = 1
             jproj = 2
@@ -88,7 +90,7 @@ module subroutine fraggle_set_mass_dist(self, param)
                ! The number of fragments we generate is bracked by the minimum required by fraggle_generate (7) and the 
                ! maximum set by the NFRAG_SIZE_MULTIPLIER which limits the total number of fragments to prevent the nbody
                ! code from getting an overwhelmingly large number of fragments
-               nfrag = ceiling(NFRAG_SIZE_MULTIPLIER  * log(fragments%mtot / min_mfrag))
+               nfrag = ceiling(NFRAG_SIZE_MULTIPLIER  * log(mtot / min_mfrag))
                nfrag = max(min(nfrag, NFRAGMAX), NFRAGMIN)
             class default
                min_mfrag = 0.0_DP
@@ -116,6 +118,7 @@ module subroutine fraggle_set_mass_dist(self, param)
          case default
             write(*,*) "fraggle_set_mass_dist_fragments error: Unrecognized regime code",impactors%regime
          end select
+         fragments%mtot = mtot
 
          ! Make the first two bins the same as the Mlr and Mslr values that came from collision_regime
          fragments%mass(1) = impactors%mass_dist(iMlr) 
diff --git a/src/fraggle/fraggle_setup.f90 b/src/fraggle/fraggle_setup.f90
index 63e2a2f5b..2e67f6c7d 100644
--- a/src/fraggle/fraggle_setup.f90
+++ b/src/fraggle/fraggle_setup.f90
@@ -48,6 +48,7 @@ module subroutine fraggle_setup_fragments(self, n, param)
       call collision_setup_fragments(self, n, param) 
       if (n < 0) return
 
+      if (allocated(self%rotmag)) deallocate(self%rotmag) 
       if (allocated(self%v_r_mag)) deallocate(self%v_r_mag) 
       if (allocated(self%v_t_mag)) deallocate(self%v_t_mag) 
       if (allocated(self%v_n_mag)) deallocate(self%v_t_mag)