On my hammerfest days I've done the first 14 km of my commute in just under 20 minutes. Most of the time it's around 26 minutes. I know this because 14 km brings me to my first natural 'checkpoint' (a level crossing) where I need to slow down.

For 13km you can count on a leisurely 30 minute ride to start with and work it down from there once you're familiar with the route.