There are 11 twisting switchbacks.

There are 11 twisting switchbacks on this road that averages 10 percent (click to enlarge).​

You wont find many more dramatic roads than Norway's Trollstigen. The serpentine strip of high mountain tarmac has an average grade of 10 percent and 11 twisting switchbacks. It's so narrow in places that vehicles over 40-feet long are prohibited. Clearly this would be a testing two-wheeled journey whether going up or down. But going downhill backwards? That's just nuts… But this guy did it. Good thing he has disc brakes.

httpv://www.youtube.com/watch?v=9QNdx2hs0n4