As long as you`re not in a trail riding group,led by a silly old fart who barely speaks Spanish ( never mind the local dialect) and who leads eight UK trail bikes through a hunting area................
....and later that night,in a scene that would do 'Southern Comfort' proud, a load of pick-up trucks blocked off the hotel car park,as a gang of semi wild looking mountain men types crammed the bar...with shotguns against the wall and feck off big knifes tucked into their boots......
...and the staff,who previously understood some English and my O level Spanish,suddenly couldn`t understand anything,avoided eye contact and generally acted as if we were invisible.......
Absolutely safe. I have ridden and travelled around there a lot - they are some of the nicest people you will ever meet. It helps if you can say a few words of Basque, normal stuff like "please", "thank you" and "2 beers please" seems to do me fine. Also, the people are Basque first and Spanish second.
There are so many interesting places and cities, it would be a crime to ride straight through - stop and explore - it's one of the best places I ever been to in the world - that's why I live in the Basque country.