Hey my friend, I'm searching exactly the same rear tire and size... It looks it's the Dunlop Elite 3 Bias... but it exists with 3 dimensions in 16" :
MT90B16-72H : width 5.24
MT90B16-74H : width 5.15
MU90B16-78H : width 5.57
I inspected all pictures and tried to find the information, but I...