Hi,

It’s tough to know what condition Rallarvegen is in right now. Parts of the road could have collapsed or been flooded. Only locals in the area will have that answer.
Personally I would not cycle it unless certain it’s OK to do so.

Try contacting the tourist centre at the other end of the route:
Haugastøl Turistsenter AS
3595 Haugastøl
Tlf: 32 08 75 64
E-mail: mail@haugastol.no

Maybe they will have more info?

Other options to get to Bergen include. Taking the train from Flåm – Myrdal – Voss and cycling from there. You find the route towards Bergen on the Oslo to Bergen page.
You could get off before Voss at Upsete but the first 30km is gravel and I’m unsure what condition it’s in.

http://www.ridewithgps.com/routes/42429436?privacy_code=AQr7GqkAmhpO32pF

You can also take a ferry from Flåm down Sognefjorden to, for example, Rysjedalsvika. Then take another ferry (only two a day) across the fjord where you reach cycle route 1 (Eurovelo 1) that leads to Bergen. http://www.norled.no/en/maps-and-schedules/expressboat/sogn-and-fjordane/

http://www.cyclenorway.com/routes/atlantic-coast-route/overview/bergen-trondheim/bergen-trondheim/