This infamous bend is here https://goo.gl/maps/3kz86ZybSA82 and definitely not 18% nor 22% but a nice 8% 
Guys, check Strava rides there, for example Ten Dam's https://www.strava.com/activities/67057155/analysis/8294/9296 and you'll see he doesn't slow down like it's 18%, but rides at 17-18 kmh, where Froome was doing 29 !
More details here https://www.strava.com/activities/67057155/analysis/8954/8963
Guys, check Strava rides there, for example Ten Dam's https://www.strava.com/activities/67057155/analysis/8294/9296 and you'll see he doesn't slow down like it's 18%, but rides at 17-18 kmh, where Froome was doing 29 !
More details here https://www.strava.com/activities/67057155/analysis/8954/8963