Heading south from Bergerac this is a continuous succession of long sweeping turns through the countryside almost all the way to Marmande. Following a short fairly uninteresting stretch to just south of th Autoroute des Deux Mers, it then provides a series of long straights all the way to Mont de Marsan, tempting you into speeds that any flic would find less than amusing - albeit there don appear to be any flics or cameras about.
Down to Orthez is of similar character, then once you turn rejoin the D933 from a short stretch on the D817, the character of the road changes completely. Scenery becomes hilly and the road becomes twisty again as you head up towards St Jean de Pied Port, an attractive and ancient town on the pilgrim trail, with lots of hotels where it is a good place to overnight if the weather in the Pyrenees is less than ideal and you want to wait in order to enjoy the scenery.
the road to the pass at the top is narrower and twisty, and done in surprisingly short time - once you are on the way down it opens up again into a wider road (now the N135) of sweeping turns all the way down to the outskirts of Pamplona.
As anyone who has experienced Spanish road systems will know, the logic is completely different from the UK and a GPS will then be invaluable in getting you either into town, or round it!
In short, a very well worth alternative to the coastal autroute.
the D 933 in our opinion is a very excellent ride great visibility including straights ans bends, recommend all bikers to try it, best points no speed cameras or police!!!