This trip is certainly a classic one in the Garda Trentino region repertoire and it surely requires to be in good athletic conditions, although its technical level can be approached even by people with medium skills.
The trail starts from Parc Hotel Flora and is scenic from the very beginning, when you  climb the wonderful Ponale unsurfaced trail, right along the cliffs of Lake Garda. You will reach the Ledro Valley Road and follow it until the crossroads with Pregasina. Here the cycling route to Lake Ledro begins and this part of the trail can be very demanding, with over 20% slopes, but it is luckily a short one. Once you reach Lake Ledro, you will cycle along its right shore towards Mezzolago, and after the lake you will continue heading towards Locca. Here, after about 1 km you will find a sign marking the direction to Chalet Pernici: from this point onwards there will be an about 9 km long 10% slope, mostly covered in asphalt. When you reach the Chalet, you will realize your efforts have been amply repaid and you will also have the chance to indulge in a nice cup of coffee. Once refreshed in body and pride, you can start riding downhill  towards Malga Grassi, the ground of this steep descent  is made of dirt and stone, but it is still quite easy from a technical point of view.