Continuing to the Atlantic Coast
To reach the Basque Coast, first cycle northwest from St. Jean-Pied-de-Port on D918. Once away from the city this becomes a wide highway slowly descending along the Nive river. There is almost always a wide shoulder, but if not, usually but not always two lanes on your side, so that cars can easily pass you. For the least traffic, depart before tourist traffic picks up at about 9:30. No other route from St Jean-Pied-de-Port leads towards the coast.
Highway D918 narrows after Louhossoa, and since you would be forced to bike in the narrow car lane, you must turn off D918 before then and follow some narrow, mainly traffic-free, back roads. Thus, after approximately 23 kilometers on D918, a big sign on the right warns of radar control. Shortly after this, on the left at a road junction you will see a white post with a red stripe next to a blue and white striped sign pointing right. Turn left here. This is D169, that goes north, then west, and then south. After about 2.5 km you cross the river and come to a T. Turn right onto D349. Continue along the river, then up a hill to a stop sign (about 4 km, sign “Cambo”). Turn left onto D249. Shortly, at the Yield sign, do not get back on D918 but stay left on D249 (the sign for D249 is on the left side of this road). Continue, making a loop, first southwest, then north for about 6 km to the traffic circle at Espalette. Here you will again encounter the main highway D918, but now with a large shoulder. Follow D918 for approximately 21 kilometers to a major intersection with a stop light and a crosswalk . (Shortly before this you will have noticed green athletic fields and white structures on your left.) Turn left here, and immediately right onto the paved bike path. In 3 km the bike path takes you into the center of St Jean de Luz. You will be 4 blocks from the sea.
From the center of St Jean de Luz, an often traffic-free bike route leads north along the coast to Biarritz, Bayonne, and points further north in France; or you can ride south on a bike route to Hendaye, Irun and points further south and west in Spain. Consult opencyclemap.org for routings.
Continuing into Spain:
This site provides detailed information only on the “Chemin” in France. Many cyclists, however, will continue on the Camino in Spain. The additional biking distance to Compostela will be the equal to that ridden in France—about 440 miles (738 kilometers), measuring from Roncesvalles. For cycling directions and general coverage in Spain, I recommend the Cicerone Guide Cycling the Camino de Santiago: The Way of Saint James – Camino Frances, available from Cicerone in the UK, Amazon and other book sellers. This book covers both the road bike route and the mountain bike route.
If continuing in Spain, strongly consider avoiding July and August. It will be quite hot, and the trail and accommodations will be overcrowded with Spanish tourists and many teenagers. Many, many more persons walk the Spanish camino than the French chemin, partly because Santiago is the patron saint of Spain, and also because you end up at Compostella with a much shorter walk.
If it is not a jubilee year (when July 25 falls on a Sunday and general dispensations are granted), and if you don’t mind hot weather, and if you are planning to stay in hotels and are willing to reserve in advance, or to sleep on gymnasium floors, then crossing Spain in the summer, though not recommended, is feasible.
Finding accommodation in gites or campgrounds is very competitive in Spain (i.e., said to be almost impossible), but many nice, small hotels may have available space. Avoid the “wave” of walkers that leaves Roncesvalles towards the beginning of the months of July and August (vacations usually correspond with months) and arrives at Compostella towards the end of the same month. As a cyclist, it is probably best to leave Roncesvalles a few days before the end of May, June or July. It is impossible to obtain reservations in Pamplona, even at many times the normal price, from July 6th to 14th, due to the running of the bulls; thus you must circumnavigate the city. If you are considering riding or walking in Spain in the summer or any time, please carefully research the experience and the lodgings.
The standard Spanish Santiago route for road bicycles is on national highways, with one-meter-wide bike lanes. It is probable that these correspond more closely to the walking camino of ancient times than does the present-day walking route. Because these highways have been supplanted by new superhighways, they usually have little traffic. It is said to be unwise, even somewhat dangerous to follow the walking camino through some of the mountainous part of Spain.
The first 400 kilometers of the route from Pamplona through Spain are in flatlands, and in my opinion the views will be less interesting than those of any part of the French chemin from Le Puy to Roncesvalles that is the subject of this website. I hold this view from looking at photographs. From Roncesvalles I rode back to St.Jean-Pied-de-Port, and continued to the Atlantic coast.