sakko: See my journal
from the pilgrimage to get a clearer idea of the route we took. I have family in Valcarlos, Navarra, so we started there, about 3km from the French border. We followed the traditional Camino Francés from there [not the walking path the whole way, though].
As for bike shops, we didn't need one. I'm a novice mechanic, and my buddy Greg worked in a bike shop for years in high school and college. In fact, we didn't even have a flat tire on the camino. I have a couple of camino books that outline where bike shops are, though. You're never really too far away from one.
Let me know if you have questions. One more thing: If you're going in June, be prepared to be bumped at the albergues. Bikers play second-fiddle to walkers, who are more abundant in summer. We went in May and had no trouble except on a rainy day in Logroño.
What really gets my goat is that walkers will take the bus to the next town, get off a few kms. in before the albergue, and then waltz in like they walked the whole day. EVERYONE knows they're total phonies, but the albergues never ask. Meanwhile, you busted your hump trying to scale the Puero del Perdón and this guy next to you was on the Scania 5000 in the back seat getting some shuteye!