Mid to late June is an optimal time. You should start in Åndalsnes and cycle road 63 over Trollstigen, Geiranger, Dalsnibba and then over Gamle Strynefjellsvegen to Lom and Lake Lovatnet. That is the ultimate wow factor on a bike – weather permitting. It’s part of the Fjord Norway route. http://www.cyclenorway.com/routes/norse-all-road-series/overview/fjord-norway/fjord-norway/