In all, Mr. Nieto won 90 Grand Prix races, starting in 1969 at the Sachsenring in what was then East Germany. That year he also won his first championship, in the 50-cubic-centimeter engine class, by one point over Aalt Toersen of the Netherlands. Mr. Nieto won five more titles in that class and seven others in the more powerful 125-cubic-centimeter class — among the smallest classes of motorcycles.
But superstition prevented him from uttering the number 13. He referred to his “12 plus 1” titles. A documentary film about his career, released in 2005, was called “Angel Nieto: 12+1.”
Mr. Nieto “was a master of psychological warfare,” said Dennis Noyes, a writer and former motorcycle racer, who had worked with Mr. Nieto as a TV commentator after Mr. Nieto’s retirement. “You never knew if his machine was working well. He’d hide that speed. And when it wasn’t working well, he gave the impression that he had extra power.”
Noyes added: “Angel would never pull away. He’d always stay in the pack and make his move late in the race. It was demoralizing.”
Leigh Diffey, a motor sports announcer for NBC, said Mr. Nieto had helped establish the sport as Spain’s second favorite after soccer. “In many ways, Angel Nieto was the forefather of Grand Prix motorcycling in Spain,” Mr. Diffey wrote in an email. “He was revered by any Spanish youngster with any aspirations of doing anything significant on a motorcycle.”
Angel Nieto Roldán was born in Zamora, Spain, on Jan. 25, 1947, but moved to the working-class Vallecas neighborhood of Madrid when he was a baby. The shack his family lived in had no running water. His father, Angel, and his mother, Teresa Roldán, sold eggs; because of that, Angel bore the nickname El Pollero, or the Chicken Man, when he started his racing career.
By age 12, he was a shop boy and apprentice mechanic in a bike shop in Vallecas. He set his sights on becoming a driver and moved to Barcelona, where he got jobs at two factories. For six months in Barcelona, he slept in the basement of a greengrocer.
“I was moving around, trying to get the chance to ride, asking, asking, asking,” magazine. “I wanted to race. I didn’t want to be a mechanic.”
He achieved his goal at age 17, racing a Derbi-manufactured bike, and was a champion within five years.
With his early victories came encounters with Gen. Francisco Franco, the Spanish dictator.
“When I won my first world title in 1969, I was doing military service, and I was told I had to meet Franco,” he told Motor Sport. “I was so scared, because I’d never seen a general in my life.”
Mr. Noyes said that Mr. Nieto and Juan Carlos had “managed to have adventures together.”
“They enjoyed their night life,” he said.
Mr. Nieto ended his racing career in 1986, when he was 39. “It had been two years since I had won the last world championship,” he told a Spanish TV network. “The mechanics left, and I thought, ‘What am I doing here?’ I said, `This is it, the winning spirit I always had had come to an end.’ ” He also conceded that he had sometimes been scared while driving.
In addition to broadcasting, Mr. Nieto managed a racing team after he stopped competing. His older sons, Angel Jr. and Pablo, who survive him, also raced bikes.
His survivors also include his second wife, the former Belinda Alonso; another son, Hugo; and his mother, who recently turned 100. A previous marriage, to Josefa Aguilar, who is known as Pepa, ended in divorce.
Mr. Noyes, an American who lived in Spain for many years, watched Mr. Nieto’s personality evolve. Early on, Mr. Nieto “wouldn’t make eye contact with you unless it was to threaten you or if he knew you,” he said.
“He’d turn his shoulders to look at you, not turn his head, like a bullfighter,” he added. “He came from a tough place.”
But in retirement, Mr. Noyes said, “he relaxed.”
“It didn’t happen overnight, but he became a funny, sweet guy who would help anybody.”