From Bergen to Moss

I would avoid the E134, personally. I live in Norway and that is one of the main east-west roads. It has only one lane in each direction, fairly heavy traffic, and no side paths.

I would go north via Vossevangen (avoid the E16) or ferry to Flåm, then Rallarvegen, then the national cycle route 5 south from Geilo, then over towards Drammen, then south along the fjord to Horten for the ferry.

If you go via Rallarvegen, you will most likely have to walk up part of the switch back road from Flåm up to Vatnahalsen, but if you prefer, you can take the Flåmsbana up. You need to book tickets for that in advance, as bike spaces usually sell out.

If you want to do Trolltunga, maybe go north from there & pick up RV7 to Geilo. That can also be a bit busy, but it’s not as bad as the E134. That said, I have not actually ridden it. It does have some tunnels where cyclists are banned, but I believe that there are alternatives for all of them (please check this)

Whatever route you do, you need to check for tunnels. There are two good sources of information for this.

Cycle tourer has information on his website, including a lot of explanations, and alternatives, but I don’t know if he still maintains the database

https://www.cycletourer.co.uk/maps/tunnelmap.shtml

Statens vegvesen (Norwegian roads authority) shows them on their map, but don’t list alternatives. There is a way to easily see whether a tunnel is open to cyclists, but they have changed the map filters. If I figure it out, I will edit this.

In the meanwhile the map is https://www.vegvesen.no/trafikk/hvaskjer?lat=59.75132&lng=10.1699&zoom=10