My husband and I will be in Scandinavia next July with four other couples. Our itinerary includes Norway in a Nutshell from Oslo to Bergen but with a two night break in the middle, staying at the Balestrand Hotel. We thought about breaking the NIN route upon arrival in Flam, using the express boat to get up to Balestrand, then two days later, returning to Flam via the express boat and continuing on NIN. It seemed to me like the first half of the 2 hr. scenic boat ride part of NIN would be a repeat of the scenery we'd already passed through twice on the express boat. And we'd have little flexibility with our schedule since there is only one express boat time that would work for getting to Balestrand and one departure time that would work for getting back to Flam. We came up with a new plan of completing NIN all the way through to Voss, then renting cars, driving to Balestrand, staying our two nights, then driving to Bergen and returning the rental cars upon arrival there. I've already spoken to the proprietor of the Hertz rental facility in Voss, who was very nice, and reserved two large cars. It will be about 5:30 p.m. when we pick up the cars, so about 7:30 p.m. when we get to Balestrand. The one-way rental fee is hefty, but with five couples splitting the cost of the two large cars, it's do-able. In fact, the per person cost of the cars is going to be about exactly what each person would have paid for the round-trip express boat and a train ticket from Voss to Bergen. So now I'm excited that we'll have rental cars in Balestrand. On our drive up from Voss, would we be able to stop and see Hopperstad Stave church? Seems a shame not to try, since we'll be passing right through Vik, but is it open in the evening? I'm looking for suggestions on how to spend our full day in Balestrand. For those who've been up there with a rental car, what were your activities? For our drive to Bergen after our two night stay, I want to drive the route that stays north of the Sognefjord (55?). rather than retracing our route from two days earlier to go through Voss. I like the fact that with cars, we can break up the trip from Balestrand to Bergen with a lunch stop somewhere. Does anyone have a suggestion on things to do/see on that drive along the north side of the Sognefjord from Balestrand to Bergen?
Just remember that you need to add the cost of petrol (atm around 16 kr/litre) and road tolls to your car budget.
If you want to stay on public transport you can take ferry Dragsvik - Vangsnes after days in Balestrand. From there it is one bus daily (Skyss 970? if I remember right) to Vossevangen. Alternatively you can take early ferry, take a pre-ordered taxi to Hopperstad stave church and bus 970 (?) from there. Disadvantage: No own pace or stop at highlights.
Your idea taking rental car in Vossevangen and driving back to Balestrand is a nice route but against your main direction. I would not do it that way. If you want to rent a car in Vossevangen use time around Hardangerfjord. There is absolutely nothing in Balestrand and on the way that you cannot have around Hardangerfjord area.
New option: If you want to visit Balestrand ultimatively the following idea: Visit Flam, take bus or fjord ferry to Gudvangen, take ferry Gudvangen to Kaupanger (visit stave church), rent a car there at Hertz. Start your drive from there to Balestrand (incl. 1 day Fjaerland and Gaularfjellet), Vossevangen (via 13 with Trollafossen / Tvindefossen, short detour Stalheimskleiva) ... Bergen. Really nice route until Vossevangen, southern part to Bergen I would drive a scenic detour 1-2 days, even more possible. Disadvantage: High one-way rental. Advantage: Very scenic rides.
Optimized idea to save expensive one-way rental fee: Take train Oslo - Voss (no NiN, no exit in Myrdal to Flam). Get car there and drive a loop Gudvangen, Flam, Aurlandsfjell, Kaupanger, Balestrand back to Voss. Return car and get back on train to Bergen (no NiN). It combines the most advantages and includes the both ones above, especially own pace in very scenic area. More details later If you want to do this.
In general: Be prepared that you will find narrow streets in Fjord Norway area - nothing impossible but big cars are not always an advantage there. Use full insurance, also glass and tyres. I know nearly no place which is more worth the money for that insurance. Also some other things to know about driving in Norway (tunnels, ferries, animals, ...). All doable but good to know. Later if you decide to take a car.