I wanted to check out the situation for Bire. So I took the train to Kandersteg and took the cable car up to Oeschinensee. And wanted to head up towards the glaciers. And I found out, that I could descent to Kiental. Well... then that was the plan. From the top station to Giesbach, it was declared with 6.5 hours. It's about 1400 m up and 1650 m down, 14.5 km distance.
The tricky part is the returning bus from Giesbach. The run only every 2 hours... as I found out, when I arrived in Giesbach.