Hi Torsten, if you use the search bar in the header and type ‘Fjord Norway’ this will be the first page to come up.

http://www.cyclenorway.com/routes/norse-all-road-series/overview/fjord-norway/

Here is the full route with POI’s explaining everything: https://ridewithgps.com/routes/39554370?privacy_code=oqFpC5A4yrqOzQid

When it comes to the mountain roads most will open up in late May or early/mid June.
You can check every mountain road status using this page:

http://www.cyclenorway.com/opening-closure-of-roads/

Rallarvegen which is on both of our routes is not usually available until mid July. You will have to take a train over sections of this.
Lastly, on your route, there is a long tunnel before Lærdal which you can not get around (you must hitchhike through or use the boats to skip Aurlandsfjellet).

Safe travels