Apparently he was very conflicted about his sexuality, as this excerpt indicates:
He had here his early struggles with his gay identity — he was celibate from his 30s until he was 75, when he met the love of his life, to whom he dedicated his last book — along with ensuing, difficult relationships. He got into a couple of biker brawls. He had a mad drive to prove himself as a body surfer in Venice (where he dislocated a shoulder and broke a few ribs) and a Muscle Beach muscle man.His last book was published this year and titled On The Move. In it he mentions more details about his love life, including the name of his lover, Bill Hayes.
The picture at the top of this post show Sacks in 1961 (at age 28) and then later on years later. He apparently loved motorcyles his entire life as well.