Trolltunga, sitting about 1,100 meters/3600 feet above sea level, is one of the most famous rock in Norway and probably the whole world.
To hike Trolltunga, you can start at Parking 2/P2 Skjeggedal, but if you book early enough and spend some extra money, you can start at Parking 3/P3 Mågelitopp, which is way above P2 and will save you around 1 to 1.5 hours of hiking if you start from P3.
This video is the ride from P2 to P3. Though the road is not long, 3.5km/2.18mile, it is a very challenging cycling climb with average grade at 11.7% and maximum grade at 16%.
You can have a quick view of the route through this video at Allerbi Youtube, enjoy!