If you're on tour, panniers fitted particularly on a tandem then NCN14 is not for you.
Leaving Darlington is great with a superb tarmac route leading ot of the city but then you hit the suburbs and things change dramatically. The route beomes a gravel/dirt track and then there are barriers preventing any further progress. The first ones require the fully laden bike to be lifted over them but then you come to 'U' shaped barriers that are impossible to negotiate with a long bike (tandem). The only option is to get to the main road (A67) and try and find the route where it heads off to Newton, not easy in the dark at night. Here it is a quiet road and no more barriers.
The route has obviously been designed by someone who has never cycled.