Flam is a little town at the end of a fjord, not to be compared with Bergen which was an important Hanseatic city and a historical core worth seeing. I was not impressed with Flam. Found the next town on the ferry ride more attractive, at least as seen from the ferry. My understanding is that Balestrand is more attractive.

From my extensive research for our holiday in Scandinavia in September we are flying in from Stockholm to Bergen on midday flight, spending the afternoon and a night in Bergen, then taking the bus and express boat to balestrand, or you can take the train. Norway in a Nutshell tour is an option which is a daytrip. We are spending 3 nights near Balestrand and then the last night in Aurland 9 kms from Flam(more attractive and less touristy than flam) so we can take the Flam railway to Myrdal @ 8.35 am and then the scenic traintrip to Oslo arriving around 16.30 so you can enjoy the scenic trip during the day. we are missing Oslo and flying straight to Copenhagen for 3 days.

Copenhagen has some great day trips. I am actually headed to Stockholm and Copenhagen in September also! I am looking forward to a day trip to Humbelbaek (sp?) for the Louisiana Museum of Art. You can also cross the Oresund bridge to go into Sweden to visit Lund or Malmo.

From Stockholm, you could do a full-day Archipelago Cruise, stopping in Vaxholm. Or you could visit the university town of Uppsala.

There is so much to do and see in Stockholm and Copenhagen that you may not have time for day trips. You will love this trip!

I did this trip in June/July.

We spent three days in Oslo, in our view this was one day too long.

We spent two nights, and one full day, in Bergen. This seemed adequate, but two full days might have been better. But Bergen is very touristy (in other words, worth seeing), so keep this in mind.

As other posters have said, Flam is small. Take the ferry to Balestrand and spend two nights. There are excursions from there, including to a nearby glacier. We spent one night, getting in on a late afternoon and leaving at noon the next day. It was a great disappointment to us that we did not spend more time here. So, do some more research on this area and spend some more time. You won't be disappointed.

You should take the train from Oslo to Flam, the ferry to Belastrand and then the ferry to Bergen. Most of what I saw in my research indicated that in the slower season you should be able to make easy train reservations. But if you know what you want to do, it does not hurt to make these arrangements in advance.

You have not said what order you will take on your trip, but you can easily (and cheaply) fly from Bergen to your next spot if you want too. We flew to Stockholm from there.

In Stockholm. make sure to take a ferry out to the islands. You can do this as a day trip, and you wont regret it.

TN

We just did this trip in June: 2 full days in Stockholm and 2 in Oslo, 4 days in Nes on the Sognefjord, 1 full day in Bergen and 4 days in Copenhagen.

I thought two days was plenty for Oslo. Probably could have added one more day to Stockholm. 1 day in Bergen was fine and 4 in Copenhagen was fine with a day trip to Fredericksborg castle. We also spent part of one day in Roskilde on our way to Aero island.

Definitely go to Bergen. Stroll around the fish market, eat there. Poke around the alleys and streets. Ride the funicular up the mt for great views of the city and harbor.

It would be a shame for you to be so close to the fjords and not even see them. See if you can squeeze in even a few hours for the trip from Flam to Gudvangen on the ferry. It is a lovely stretch of the fjords.

The Stockholm archipelago is a must. We were advised to take the Cinderella boat out to Sandhamn for the day. Look on the Skansen and Stromma websites. Also a trip to the Drottningsholm castle looks like a must do.
I have heard Flam is a disappointing place to stay - and loses the sunlight very early. Be sure to look at the time tables of the ferries between the stops in Sognefjord. Balestrand/Dragsvik or Nesgard look far nicer, or if you need to be near Flam because of ferry /train times etc, rather stay in Aurland or Gudvangen.
If you book the Oslo to Flam tickets early on nsb.no you get miniprix tickets which are lowfare prices. Worth a look. Look up Rick Steves website and Norway in a Nutshell site too. Be sure to book the Oslo ticket so you travel during the day to get the best out of the views.