What's the hill and route, specifically? (I train people on roads in Sonoma, Napa and Marin so I am INTIMATELY and PAINfully familiar with those roads.)

For super steep stuff, I sit and spin or grind, and swear, as appropriate. I swear a lot. We just did Skaggs Springs/Ft Ross loop which has sustained (over a mile each, consistent) of 15+%. Indescribably nasty. But you feel good when you get done.

Anyway, let me know your route and if I have any insight I will let you know.