Hi Roddy,

1. The prevailing winds come from the southeast, so Bergen to Oslo will have more tailwinds in theory. But I have ridden Oslo to Bergen and never felt the wind was an issue. Lots of mountains shelter you.

2. It’s hard to say but you should expect at least 80km will be unrideable. When you get to Haugastøl (coming from Oslo) you can test the first gravels section out and see if it’s ridable to Finse. If not turn around and take a train to Myrdal. From there see if you can ride down to Flåm and take the train back up to Myrdal and then jump on a regional train to Bergen, where by you will jump off at one of the small stops before Voss. This route is still amazing without Rallarvegen.

3. There is one section after Hokksund (coming from Oslo) that climbs on gravel which is 8/10 for a bit. You can skip this section and cycle road 40 instead (but expect traffic). And you must keep off the E134 to Kongsberg (use the old road). There are other climbs further up towards Geilo and I would rate them 6-7 out of 10.

4. Here is the route and GPX files: http://www.cyclenorway.com/routes/norse-all-road-series/overview/route-1-2/
How to download the gpx files: http://www.youtube.com/watch?v=hk3LkZ1SArU&feature=youtu.be