La Stretta - Forcola di Livigno really very tedious, more walking than riding. But the path is open again throughout. Alternative would be towards Livigno via "La Stretta DH" (2/3 easily rideable, first third depending on technique) and then 200m on the gravel road up to Forcola. This makes more sense and is easier, especially for e-bikers.
The trail to Fuorcla Minar and Bernina is also completely rideable for fit biobikers except for two or three small rocky sections!

The path from la Stretta to Fuorcla Di Livignio is barely passable. The exposed paths are one thing, there is also a rockfall that has to be crossed. Very dangerous, especially when wet. The last stretch of about 500m can be ridden reasonably well. Tour completed in Sept.2024 Tomi

The way

La Stretta to Fuorcla di Livigno is not worth it in my opinion. The difficulties and exposure are one thing, but the trail is relatively rough and forces even good riders to dismount around 15-20 times.
Those who like blocked S3 trails will love the descent through Val Minor. Top! But you can also get there in other ways...

I would also rate the tour as a 4 in terms of riding technique. The first descent is exposed and technical. A Black Diamond on Trailforks. Comparable to Stockalperweg, for example, but more exposed.
The rest less so - but it might make sense to rate the key sections.

In any case, I would not recommend this tour to less technically experienced bikers.

Everyone else will have fun!

We did the tour on 26.06. The part on the Bernina Pass is beautiful and easy to ride. Up and down. But the trail from La Stretta to the customs is not a level 3 for us. More like 4 or 5 for those who like a challenge and like to push or carry. Everything is fine. The slope is also not to be underestimated for me, but my friend certainly had a problem.

Tour made on 27.06.2021. From Alpe Stretta to Forcola di Livigno there are still snowfields in places.
One section from La Stretta towards Forcola di Livigno is a bit dangerous with flat bike shoes. But it is doable.
The Val Minor was unfortunately still too heavily covered with snow, so I rode down from the F.Minor towards the Bernina Pass.

I tackled the tour on September 16, 2019. I started in Morteratsch and took the initially steep trail to the left turn over the Bernina Pass road into Val da Fain. It was still late summer temperatures (legs and arms short) and I was completely alone. The section between Pass La Stretta and Forcola die Livignio, which is often described as difficult, should not be underestimated. However, bikers with a head for heights and good mountain skills can master it without any problems. Pushing and carrying passages are unavoidable. The well-built climb after the Forcola di Livigno is a dream of an uphill. I preferred the route through the Val Minor. Despite some initially unrideable sections, it was a dream of seclusion. Back in Lagalp, I took the Bernina Pass loop and the trail on the left side of the valley (not Alp Grüm) towards Poschiavo. With a few short, crisp intermediate climbs, this is also a recommended singletrack trial

Great tour with lots of munggen in Val da Fain. I have to agree with everything t.schaeffer said about the route. Unfortunately, it rained and hailed from Alp la Stretta onwards, which didn't make the route to Forcola di Livigno any better (even on foot). The first time, I descended from Fuorcla Minor through Val Minor, which was not only very challenging due to the boulders, but also no fun. On my second attempt, I followed the bike route to the Bernina Pass, which meant another climb, but was more fun and faster.

I rode the tour today 11.08.2019. Super tour, the description is appropriate.
The trail from Pso. Stretta to Forcola Livigno is exposed in places, as described. I found it normal for a red and white marked hiking trail at this altitude and never felt endangered at any time. I carried the bike for about half of the trail, which was no problem. Surefootedness is required. I would not recommend an e-bike. Overall, a very nice tour. To assess/compare: my Level S2, touring bike 13kg 150mm.

We rode the route on 10.7.19. The route from Pontresina to the Montebello bend can also be ridden in the opposite direction for the return to Pontresina. The ascent to the La Stretta pass is very beautiful and easy to ride. The rest of the way up to the Forcola di Livigno is very, very exposed and in our opinion only suitable for riders with a head for heights and a slight inclination towards life. Several people turned back on this sunny day and chose a different, less risky option. The poor condition of the path - rocks breaking away to which the anchoring of the path safety device (!!) is attached - further increases the risk. From a purely technical point of view, the route would certainly be very nice, but we are still hanging on for dear life. From the Forcola di Livigno, a very beautiful and easy to ride (and not exposed  ) path leads up to the Fourcla Minor. From there, we chose the variant via Val Minor with its technically demanding single trail towards the Lagalp valley station.

The upper part of the descent to Forcola Livigno is very exposed. Path very narrow. Good combination: from Forcula Livigno, ride along the road towards Bernina and then turn left onto the trail towards Poschiavo (no. 436)

Super

A great and varied tour! We rode it on 05.07.2019, the ascent in Val da Fain is very pleasant and you easily gain altitude. There were still a few short snowfields around La Stretta, but they were easily passable. The descent to Forcola di Livigino was not completely passable for us, the hiking trail there was covered with boulders over a length of about 20 meters. The ascent to Fuorcla Minor was again very pleasant, with uphill bends ;-)

Really great tour! I did it in fall 2018. The return variant via Val Minor is also recommended!