It has two possibilities, front or back.
Theory 1/ Toss a coin.
Theory 2/ Don't do what Triumph (or BSA, or Royal Enfield, or Velocette take your pick) do
Theory 3/ Do what Triumph (or BSA, or Royal Enfield, or Velocette take your pick) do
Aren't there more important things to worry about?
cheers
wakeup