this tire question has been kicked around since forever. when i ran a 130/80 Tourance on the front, it was always with the rotation arrow, TKC the same.
when the question was asked of Metzler, here's what they had to say back in 2010...
From: Metzeler B2C Moto, US [firstname.lastname@example.org]
Sent: Fri 3/12/2010 8:17 AM
Subject: tourance tire - rear mounted on front
One should never run a tire backwards. The exception to this rule is if the tire is marked (at the sidewall arrow) as a dual rotation tire. This happens typically only with scooter tires but virtually never with a motorcycle tire.
Tire's have a tread pattern and tread cap (compound) orientation that is important to the safe handling of the application and by running the tire backwards one could help fester a future problem with the tire. Then one should note that the construction differences between a front and rear tire are radically different in material, shape, and compound so this too could have a negative effect on the handling of the bike. The last thing to look at is the possibility of uneven wear when the tire is used backwards. Thanks for the question and have a great day.
NA Metzeler Consumer Affairs
i really liked the 130/80 rear mounted up front, and wouldn't hesitate to do it again, especially for a long range trip where tire wear and wheel protection (an added benefit) are very important. i ran this setup for 16,000 miles, all weather and road conditions imaginable.
people have their opinions, but if you're going to take a hard stance in the discussion, at least have some first hand experience on the subject.