Let’s start with the basics. The surface and the gradient are very unlike the rest of Mallorca. The road is average to poor in places and up to 19% steep when you lest want it to be. There are almost no sign posts.
There is literally no traffic.
Take care also as there are very few signposts – the first time we did it we managed by just following the gradient – if the road rises follow it! It is tough to see signs through all the sweat coming into your eyes anyhow.
There are two ways to the summit of this climb. The more picturesque and easiest way (and therefore not the toughest climb in Mallorca!) is from Esporles and takes you through the Es Verger vineyard. This however is cheating, and in our opinion the best (read toughest) is from the South.
Sobremund is unlike any other climb in Mallorca. For a start, the surface is only OK at the start and halfway along until the summit is full of badly repaired potholes and loose gravel. Then, the gradient reaches a maximum of 19% which is unheard of in Mallorca where the norm is a gentler 5 – 8%. Our recommended route (GPX file here) descends through the Es Verger vineyard into Esporles as the surface is better this way. Not brilliant, but better. You will rejoin the ma-10 coastal road back to Pollenca just before Valldemossa.