To write a little anti-cyclically: I found the upper section up to Rasa much more difficult, as it was quite exposed in many places and also technically challenging. There are no mistakes allowed and an absolutely safe riding style is essential. The forest air in Ticino is also thin and doesn't slow you down...
The lower part is blocked, moderately steep, but quite easy to ride and forgiving of mistakes. All in all, a typical Ticino trail: technical, wild, with lots of surprises, absolutely worthwhile.
At the river below, after the bridge, follow the official hiking trail to the road. This is a much more pleasant ascent than the route on the GPX track.

I rode the tour today, long ascent from Ascona, about 2-3h (I had 2 but rode through and quickly) uphill without even a straight line. After that, however, the trail begins. The upper part towards Rasa is quite tricky, as there is already a lot of foliage on the trail, covering the roots, stones and streams. However, I think if you can see everything, it should be quite doable! (but certainly not for beginners)
The second part from Rasa I followed the GPS track! This part is really difficult to ride!!! Steep, blocked and lots of water gullies after the heavy rainfall! Anyone who can ride the whole trail is a real master!!! A large part is for experienced riders, but even they will reach their limits! Certainly not for the 0815 biker, they will cry the whole trail!!! :)

Conclusion: I enjoyed the trail! The ascent is tough but absolutely worth it with the wonderful view!!! The descent is very technical and difficult to ride!!! However, if you're looking for a challenge and don't mind a couple of pushing passages, this is the trail for you! But you have to have your bike under control!!!

I had a "grin" on my face on the suspension bridge.... ;)

Ride on....

Ridden on 22.06.2023. I think the riding technique rating 5/6 is justified. The lower part is very difficult in places, even unrideable (for me), but overall these are only short sections. However, I wouldn't do it in the fall when there is a lot of foliage.
Conclusion: A challenging tour for technicians in a very beautiful landscape!

Tour ridden on 04.02.2023. A great ascent, always the lake in view, beautiful in the sun in winter. But then pushed down a lot at the start. The reason was the many leaves, some of them knee-deep. But it's not the tour that's to blame, but my impatience to do this tour in winter :-) So better wait a little longer! But otherwise great, highly recommended. Technicians get their money's worth.

User brot01 and wildspitz74_32033: Why do you go via Bordei, climb via Ascona to point 1306, then follow the described route (as in Map and according to user mix_69999617), then you have a really great enduro tour for experts!

I rode the trail on 30.8.2022.
Start in Ascona and over the road up to point 1306. A hard, long, steep climb. From about halfway up, the gradient eases a little.
From point 1306, a moderately difficult trail starts to Rasa, with roots, stones and flow passages in the chestnut forest, typical of Ticino. The trail is not suitable for beginners, but not very difficult either. It is ideal for warming up for the descent from Rasa to Salmina, because that's where it gets down to business. The descent starts moderately as far as Corte die Sotto and from there remains steep, rocky, blocked, with steps and hairpin bends all the way down to Melezza. This descent is rightly classified as black and should only be ridden by good technicians. But they will have a lot of fun on this section.
What fireworks! At the suspension bridge at the bottom, you'll be cursing or grinning up to your ears.

We were out and about in the Centovalli at the beginning of May. After finally arriving in Bordei on the asphalt road, we were looking forward to a "moderate" singletrail via point 802 to Rasa (according to the singletrail map). Unfortunately, the experience turned into nothing, as biking on the trail was practically unthinkable. We had to push the bikes for about 1.5 hours through the beautiful Centovalli forest. There are certainly passages on the trail that a good biker can master by riding, but a classification as "moderate" seems very sporty to me. There are always huge boulders, streams and root stocks to overcome. When we finally arrived in Rasa, we decided to take the cable car for the ride down into the valley. (Enough hiking!)

The trail on Rasa is mostly rideable. A few short push sections are possible. When there is a lot of foliage in the fall, it gets tricky when you can no longer see the stones and roots. On the descent, we overtook a few bikers who had pushed a large section. From Rasa in the direction of Bordei it is no longer a pleasure even for good bikers. 90% pushing is the order of the day. We have noticed that some e-bikers or bikers with moderate riding skills are tempted to take this route and fail miserably. The lower section is not recommended.

A really worthwhile tour! Everything is free of snow and can be ridden immediately. The ascent is long but you are always rewarded with wonderful views down over Lake Maggiore.

The first trail to Rasa still has a thick layer of foliage, is rooty and rather flowy. Always nicely along the contour line.

It only gets really cool from Rasa onwards. Somewhat blocked and exciting. Lots of steps. You should be able to shift the rear wheel. However, I think 5 out of 6 points for riding technique is a bit excessive compared to other ride tours.

But really a great tour with very little hiking traffic on the descent (we rode it today on Saturday).