Camino Primitivo can be done cycling but that does not mean it is the most suitable route to do on two wheels. When I did it personally in 2010, I could see firsthand its stunning beauty but also its extreme hardness. The further I went and the more I analyzed it, the more I realized that in terms of landscape is undoubtedly the most beautiful of all the routes, its paths go deep into lush forests, up and down through mountains with breathtaking views over green valleys, dotted with small towns and villages.... the countryside and mountains all around us ... but how difficult it is to cross it biking... at least if our intention is to follow the path marked with yellow arrows. In short, I loved this route, but forgetting my passion for cycling and my status as bicigrino it does not hurt to recognize that this is a journey that will undoubtedly be infinitely more enjoyable walking than cycling.
So for those who make the approach of going down this route, be warned that you will face a route through a very mountainous and rugged area. If following the original road, there are areas where it is impossible to go on the bike, not only on rises (what can be considered as normal) but on the downhills as the roads are full of stones and steps that generally make much of the route not cyclable. I insist that this does not mean that you can not make it biking but you have to take precautions and go through this route alerted and prepared to face it.
Anecdotally tell you that when I made this route I met two Canarian guys who just had consulted a website and a map and had concluded that this was the shortest Camino de Santiago and had therefore decided to jump into it, in the month of February!! only with the knowledge that it was the route that would take them to Santiago in less miles, but obviating the mountains, thousands of meters high, and wooded and muddy paths lost in the depths of the forests ...., that is very bucolic to give a walking tour, but a true martyrdom when doing the route, dragging a bike and heavy packages by hills and muddy trails.
Camino Primitivo is often presented as an alternative path in the Northern Way (which traditionally begins in Irun) and when arriving to the Asturian town called Villaviciosa in some guidelines there are these two possibilities, taking the path "of the coast" or going to Oviedo to venture into the mountains and take this Camino Primitivo we are talking about. Just to clarify those people who have doubts about the constraints described above, about the peculiarity and hardness of this route.
Given these warnings make clear that it can be perfectly done by bicycle, but you will have to go well prepared physically and be aware of the difficulty. Emphasize its beauty and its spectacular mountain scenery. If you plan it with stretches and routes by roadside, roadside that otherwise has no excessive traffic, it can also be an excellent alternative to enjoy, as I say, of a really beautiful path scenically.
On the route there are few dilemmas in alternatives and variations, as on other routes and paths of Camino de Santiago, in most of the sections we always have the roadside near us and we can seek the good company of asphalt if necessary. But we must make special mention to two specific sections that should be considered, as the path and the road separate a lot and they are also sections rather complicated and dangerous for make them biking, and even more if there are adverse weather conditions. I refer to the vicinity of Puerto del Palo in the area of POLA DE ALLANDE and the famous and mythical variant of HOSPITALES.
After TINEO we enter in the vicinity of Puerto del Palo and just after passing it we have the option to either continue by road to POLA DE ALLANDE or take the variant of HOSPITALES.
If we look at the profile of the stage we will see that POLA DE ALLANDE is at the bottom of a deep valley and you have to cycle through a big downhill and then get the big "mega-raise" and head to the mountain pass that is located none other than 1,146 m. high. In exchange through HOSPITALES variant we will not have to descend into the valley and we could keep the dimension of altitude as we brought before more or less, with only a drop ahead of about 600 m.
The path of HOSPITALES is very beautiful and lonely, but also very hard and dangerous if weather conditions are adverse, and in case of fog or snow we can have a really bad time. In this area there is no possibility of provisioning as there are no towns in nearly 20 km and in the present case, "the bike-pilgrims case", it is recommended to go down to POLA DE ALLANDE and then go up the mountain pass of PALO by road to seek safety on the route and some company in case we have any contingency in route. For those coming to this area with end-stage approach, it will not be a bad idea spend the night in POLA DE ALLANDE to face the mountain pass in the morning with renewed strength and courage.
Also in the same area and after passing the pass of Palo, after a long descent we should continue by road as the asphalt and the path frolic through this area, being the route paths and mountain trails with some danger when going through them by bike, we will get to the small village of LA MESA, here the path is far from the road and goes through a difficult mountain trail very hilly and that can provide technical difficulties to follow cycling. My advice is to continue by road to the dam of the swamp of GRANDAS DE SALIME for two reasons, because on the road we will be a lot safer and accompanied and the main reason, we can enjoy of the stunning views that the area gives us, in which we sometimes get the feeling of looking through the window of an airplane and we can see down, very down some dreamy landscapes, dotted with green fields with horses trotting in semi-freedom and precious stone-roofed villages that seem anchored in time.
The conclusion is that Camino Primitivo is a route to walk rather than to go on bike. It is not impossible to complete it by bike, but you will have to push the bike a lot of times and take it calmly in order to enjoy it intensely.