Help with itinerary around Voss & Bergen

Welcome to the forum.

Norway has large distances and a respectable but comparable thin public transport infrastructure (due to low number of people).

That said I recommend reading "Getting around Norway" and "5 spectacular trips around Fjord Norway by rail, bus, and boat".

I do not see Voss as a meaningful base for multiple day trips with public transport, maybe with a rental car. Staying in Flam and exploring "Flåm, Myrdal, Nærøyfjord, Gudvangen, Stegastein viewpoint" from there seems more meaningful for you plans. You can book trains and buses via Vy.no.

For days in Flåm try to avoid cruise ships in port. This relates to your booking question, e. g. boat, bus or train tours to / from Flåm. The capacities of attractions are quickly filled up when a ship with up to over 6,000 pax dock / anker in Flåm.

From Flåm you can do boat tour for exploring Sognefjord as well. Be aware that parts of majesty of Sognefjord are not seeable for human beings. Only 3-4 kilometres to ferry quay Vangsnes the fjord reaches a depth of over 1,100 metres.

For exploring Hardangerfjord area by public transport (incl. ferries) you can choose staying in Norheimsund, Eidfjord or Odda. Utne seems not meaningful in your context.

Tip: Be in Bergen from May 16-18 to co-celebrate Norway's constitution day from morning to evening.

Hope this was helpful.

There's little besides the train station (transfer point to the Flamsbana) in Myrdal, though I assume there are hiking opportunities.

The mainline rail fare from Oslo to Myrdal is variable. You will save money by buying that ticket early. I've seen references to entire trains being full, but I don't know how likely that would be in May. The train from Voss to Bergen seems to be no problem; it runs more frequently, I believe, and there are no reserved seats, making a sellout impossible. Despite reading every forum post that comes along on the topic of the Norway in a Nutshell route, I just don't know how frequently there's insufficient capacity on the Flamsbana or the Flam-Gudvangen ferry.

Thank you MarkK & acraven for your detailed responses. Really appreciate it.

The trick in this booking something last minute is to travel counter peak.

So most people, especially the Norway in a Nutshell in a day crowd, travel on the morning trains from Oslo.

So you take the afternoon train from Oslo to Myrdal for Flam. That will put you on an early evening train from Myrdal to Flam long after the NiN crowds have gone on their merry way, and well after the returning cruise ship passengers have travelled.
And you arrive in Flam well after the cruise ships have departed. It even gives you an extra morning sightseeing time in Oslo.

Likewise on the Flam to Gudvangen boat- avoid the fancy tourist boats (the ones the Nutshellers use) like the plague, instead take the public Lustraabaten ferry. The ferry berths in Gudvangen overnight. So look at taking the first departure in the morning to Gudvangen (before the Nutshellers can physically have arrived from either Bergen or Oslo) or the last afternoon ferry from Gudvangen to Flam (nutshellers from Bergen use the morning and lunchtime services).
I've not actually seen cruise excursions offering the Gudvangen boat ride but if they do they will probably use the tourist boats, not the ferry. Especially the last afternoon trip from Gudvangen cruise passengers won't use that as they need to be back at the ship.

Yes, but there's high demand for lodging in Flam and low supply. Be sure you have a place to sleep before buying transportation tickets that require a night in Flam.

Thank you very much for your responses isn31c & acraven. Very helpful and informative.

First of all Thank you for your responses. Got some very informative answers. We changed our mind and decided to rent a car for part of our journey. Here is what we have finalized.

(1) Oslo to Flam (3 nights in Flam)
(2) Flam to Bergen ferry (stay overnight).
(3) Pick up rental car from Bergen and drive to Vangsnes via E16 & 13 (2 nights in Vangsnes).
(4) Vangsnes to Eidfjord (Stay overnight).
(5) Eidfjord to Norheimsund via Odda (Stay overnight).
(6) Return car and fly out of Bergen.

1) Is this itinerary too hectic? Based on google maps directions, it shows at most 3-4 hrs drive once we have rental car. So far we have only booked accommodation in Flam so we are flexible.
2) Are there any places or roads we should avoid or any scenic routes we should add?