1) At the end of the first climb (just before Arcegno), the route suggests leaving the paved road and taking a hiking trail to the left (which also leads to Arcegno). Be sure to continue on the paved road to Arcegno, unless you enjoy carrying your bike. The hiking trail is completely unrideable for 60% of the ascent. In Arcegno, you’ll simply rejoin the trail.
2) Many of the previous comments mention the incorrectly mapped first descent. You can easily avoid this problem by riding straight ahead at point 2'700'838.10, 1'113'931.71 and NOT turning left downhill as the original trail suggests. Then follow this trail straight ahead. The trail/hiking path is marked throughout with trail signs labeled "Losone" and is a perfect S2-level trail in terms of difficulty.
With these two changes, it’s a truly great S2 half-day tour. Varied, with good views and great single-track trails that are fairly consistent at the S2 level.

A really nice tour and with Swisstopo you can find the right way without much searching. However, I have to agree with the previous speaker. In terms of difficulty, it is not a two as there are two or three places that I would classify as 4 or 5. But you can push everything so that these sections can be passed. Apart from these places, the tour is mega. Trails in the morning and swimming in the afternoon. What could be better?

At kilometer 9.5 there is a large fallen oak tree and, depending on your attitude, getting through is impossible, tedious or challenging :-)
Better ride right at the pond directly to the Riposo campsite.

Tried it today. Unfortunately, I couldn't find everything straight away. Carried the bike up and tried again. Tend to keep right after the entrance. Otherwise it really goes down the hiking trail and this is not rideable. You are sure to find a suitable descent. There are several options after the first ascent. Unfortunately, the second ascent was closed today due to woodwork. I will certainly try again. It's not about the one trail. It's about biking and that also includes carrying passages. A fitting end to the year.

I rode the route a few days ago. A leisurely tour to warm up at the start of the bike vacation ;). As already written, the track is not always quite right, but I had no trouble finding the right way, as there is actually only ever one way.

I rode the lap yesterday. Instead of the first descent, I took the Strava segment 'Pistino Enduro Arcegno'. Starts and ends at exactly the same place as the original route. It's maintained by locals, has a few jumps and berms (each with a chicken line) and some crunchy sections. Enduro like. I rode the rest according to the track. It was fun that way.

I rode this route today. I got on at "Riposo" in Losone and rode up to Ciossa as indicated under "Map/Track". The suggested route is only feasible by carrying the bike up (...and in the opposite direction only for the Olympic champion in the Donwhill...!). I have to agree with "dodoadams", the suggested route seems absolutely unfavorable; doesn't seem to be listed as a trail on the singletrailmap-Locarno either. From Ciossa, however, it is a beautiful tour, especially the asphalted traverse from Monte Verita to Gruppaldo with spectacular views.

Poorly described route and the data is not correct in many places in my opinion, or the description is not correct.

The track seems to be wrong. On the first descent in particular, it is better to stick to the well-trodden path instead of descending to the left, following the track in the fall line. What doesn't look good on the map is hardly any better in reality. There seems to be a nice trail, but it runs differently to the track on the map. (see singletrail map).