Carl Walker, 32, targeted 14 women and children aged between 12 and 50 as darkness fell in Hull, including attacking four on the same evening.
On each occasion he quietly biked up to his victim on the footpath and assaulted them, shouted abuse and threats and then made his escape.
His victims were forced to run away or seek refuge in nearby pubs – and Hull Crown Court heard yesterday many were still traumatised.
Police drafted in extra officers to hunt the offender and Walker was questioned and bailed, but committed two further attacks, one on a victim aged just 12.
Handing Walker a seven-year extended sentence Judge Michael Mettyear said: “Your victims were left shocked and very frightened after the assaults which were followed by disgusting words or nasty threats. Many of them haven’t fully recovered from what happened.
“You pose an ongoing risk to women and particularly female children.”
Prosecuting, Jonathan Sharp said: “He took to riding his bike, normally at night, in the city centre groping or grabbing women. After the initial assault he frequently became aggressive, threatening and venomous and seemed to relish his victims’ terror.”
The attacks began on October 16 last year when Walker, riding his mountain bike, approached a 31-year-old woman and grabbed her right buttock before pedalling away.
The next day he targeted a 21-year-old. But in what was to become a feature of his assaults, he then returned, saying over and over again “you want me” and forcing her to run away.
He left a 17-year-old terrified when he sexually assaulted her, then screamed “I want to rape you”, and he forced a 50-year-old woman to run into a pub after another incident.
She told police she had “experienced a feeling of fear that night I never want to experience again”. This was one of four similar offences he committed all on the evening of October 19.
He was questioned but bailed pending further inquiries, and committed two further assaults – one on a 12-year-old girl who was walking home with friends of the same age.
He admitted 14 counts of sexual assault at an earlier hearing. He was also made the subject of a Sexual Offences Prevention Order.
Mitigating, Paul Genney said Walker was a loner with “very, very few friends”. He added: “He seems to have very little sympathy for any of his victims which may be a result of his wretched upbringing.”