The onward journey from the Amthorspitze to the Weißspitze is not feasible for me by bike or absolutely not recommended, as there is a 5m high vertical ladder on the way. The bypass/alternative route on the old hiking trail is also absolutely not fun with the bike. It is then very difficult to cross the Weißspitze by bike. The way over the summit is easy climbing and bypassing the summit over boulders is no fun at all. The downhill trail to the south is often not ridable in the upper area (blocked, too steep, ...). Overall, it is absolutely not recommended (unless you are traveling without a bike; then it is beautiful).