[Johngalt]

On the oem continental TC70 rear tire there’s an arrow “—REAR—>”. I understood this as “the rear of the bike this way” and mounted the tire with the arrow pointing to the rear of the bike.
The thread pattern on the tire looks like it it doesn’t matter wich way is front or back.
Question: is it a big deal if the rear tire is pointing the “opposite way”?

 

[KTMasean]

I guess if it would not matter the manufacturer would not bother putting an arrow on a tyre.

 

[KiriBKK]

The tire's designed to be mounted with the arrow pointing in the direction of wheel rotation, not to the rear of the bike. The "rear" on the sidewall just indicates that it's a rear tire. Mounting a rear tire backwards is probably not a huge deal, but depending on the tread design it may make it less effective at displacing water in wet conditions.