Which is the hardest surfaced climb that could be climbed with a race bike and with 39-27?

My vote goes to Alpe Vaccaro! It is at least 200% harder than Cima l'Angliru! (Still in Italy - did two easy today - Monte Bisbino & Monte Generoso + a very hard one: Passo Bonello. Easiest day yet due to Vaccaro yesterday.)

Fully surfaced , Jerry !
Congratulations : I had so much difficulty to climb the Cima l'Angliru !
Two times it : waaw ! What to say else : waaw !

Actually I am not sure you would want compliments for climbing this as it is indeed bordering on the insane - it may well break both your bicycle, your body and your spirit. I have been crying when I simply reflect on it and it was hard get from my mind even when I wanted. I was trying to figure out if there was one inch in my body where I did not have severe pain and I trouble standing while coming back. There is no way one could ride just the same the day after - doing as much. The only way to suceed climbing it consists in trying to go as slowly as possible when the inclination is not so high, which still would not be more than just helpful here. I would not recommend this climb to anyone - I am not an evil person!