Tinnsjøen Rundt — The 145km Loop Around the Tinnsjø Basin from Gaustablikk

Tinnsjøen Rundt looks like an average day on the bike until it isn't. 145 km, 2,366 m of climbing, three Cat-graded climbs. On paper it is a hard but predictable route. In practice it is the 50 km between Ørvella and the plateau that becomes the problem — the section that looks gentle and isn't.

You leave Gaustablikk and roll straight into Krysset–Flistjønnskaret. It is a fair climb — 6.8 km at 5.1% average for around 400 m of gain, Cat 2, good asphalt. Ride it easy. There are 137 km still to go, and the day's hardest climb is saved for the end.

Over the top a 30 km descent drops you all the way to Sauland in the valley floor. It is a long, shallow descent — not technical, no tight corners — and it is the only real recovery you get before Sandviken.

Sauland has a short, unpleasant passage on the E134. You ride 4 km on the busy main road, and it is the only part of the day that isn't enjoyable. At Ørvella you turn off the main road and onto quiet country roads again. This is where rural Telemark starts.

From Ørvella the road climbs steadily for 50 km. You pass Tinnsjøen and continue up to the plateau at around 750 m, and although the average is 3% the gradient is not even. Two sections of roughly 2.5 km at 6% average come toward the end of the climb, just before the plateau. The rest of the stretch is shallower. It is precisely this combination that takes the legs: the steeper sections deliver a shock-dose of gradient, and the shallow gradient between holds the legs in constant work without it feeling like climbing. You turn the pedals uphill for almost two hours, and by the time you reach Sandviken the legs have done substantially more work than you think.

When the road drops toward Tinnsjøen the view opens up again — the lake sits there with the mountains arranged behind it, and Sandviken Kafé i Tinn is right at the water. You have earned the stop. The terrace is covered, the menu is honest — pizza, burgers, baked goods, coffee. Remember that Zombie Hill is 20 km away, and it pays to not eat too heavily even if the long climb has left you hungry.

After Sandviken the road runs flat along the eastern shore of Tinnsjøen all the way to Rjukan. It is good riding, but it is a transition, not a section. It is at the foot of Zombie Hill that the real work begins.

Zombie Hill is not called that by accident. The climb is the finale of the Norseman Extreme Triathlon — the run leg, not the bike leg — and the name comes from what it does to endurance athletes who have already been on the move for 14 hours. On the bike it is 6.8 km at 9.6% average with 654 m of gain, Cat 1. It is steady-steep from the first metre to the last. There are no flat sections where you can gather yourself. Worth a mention: the KOM is held by Remco Evenepoel — set during the Tour of Norway. For most riders, under 40 minutes is a good time with 130 km in the legs. The asphalt is good and there is nothing wrong with the climb. It is simply hard, and it comes at the end of a day that has already taken more than you think.

For those who want a little extra: at the Gaustablikk turn-off near the top of Zombie Hill you can continue up to Flistjønnskaret instead of turning home. It is a few extra metres of climbing for anyone who hasn't had enough, and you roll back down to Gaustablikk afterward.