Donald Lock, 79, was knifed repeatedly in a “frenzied” attack after he got out of his car following a minor crash on the A24 at Findon, near Worthing, West Sussex, last night.
Armed officers arrested a 34-year-old suspect, from Worthing, West Sussex, at 2pm in connection with the alleged road rage murder.
In a statement issued through Sussex Police, his family said: “Don has been a keen cyclist since the age of 12 and had been an active member of the Worthing Excelsior Cycling Club since 1960.
“He was not your typical great grandfather and was still cycling up to 150 miles per week.
“He still holds the club record for the 24-hour time trial having remained unbeaten for 44 years. He was full of energy having recently been given the all-clear from cancer.”
Mr Lock - who had two children, four grandchildren and five great-grandchildren - was to have a sixth great- grandchild later this year, his relatives also disclosed.
His family added: “Not only was he passionate about cycling but he had also been supporting Brighton and Hove Albion since the 1940s and was a season ticket holder.
“He loved travelling the world with his wife Maureen and he adored his family. He and Maureen had just celebrated their 55th wedding anniversary.
“Don leaves son Andy, daughter Sandra, four grandchildren, and five great-grandchildren with the sixth great- grandchild due later this year. Don had lived in Worthing for 55 years and was a popular member of the community.
“He was hugely loved by his family and friends and could often be called upon for his cycling or travel advice. Words cannot describe how much he will be missed.”
Mr Lock, a long-time member of the Worthing Excelsior Cycling Club, died at the scene at around 8.40pm last night despite attempts by paramedics to revive him.
Before he died, Mr Lock had attended a social gathering of Worthing Excelsior Cycling Club members, its secretary Adrian Palmer said.
Every Thursday during the summer, the club stages an evening 10-mile time trial, which starts just outside the village of Washington.
Mr Palmer said: “I don’t think he was involved in the marshalling, but he turned up and socialised with the rest of the group, and then he went home - and this happened.”
A Sussex Police spokesman later said detectives were “not looking for anyone else at this time” in connection with Mr Lock’s death.
The arrest was made less than an hour after Detective Superintendent Adam Hibbert, of the Sussex and Surrey major crime branch, made a televised appeal for the public’s help.
Flowers were placed and tributes were paid to Mr Lock as cordons remained in place on the bypass where the killing happened.
Mr Lock’s daughter, Sandra, and granddaughter, Kirsty, were among a steady stream of people who arrived at the scene to lay flowers.
The distraught-looking pair held each other for support as they stood close to the spot where Mr Lock lost his life.
Part of a card laid at the scene read: “Grandad, there are no words to express how I’m feeling. I have lost a very special grandad. My only grandad. I love you so much.
“You will be truly missed by so many people. I just wish I could hug you one last time.”
Mr Palmer described Mr Lock as a long-serving, committed member of the cycling club who for many years was its “backbone”.
He said: “Don was a kind, gentle and fair man and a good friend. He was a key member of Worthing Excelsior Cycling Club, in fact he was the backbone of the club for many, many years.
“He was also well-respected throughout the cycling fraternity. He was a member of Worthing Excelsior Cycling Club for about 50 years and served the club well in many different roles.
“Don was an enthusiastic member and, although he no longer raced, would always support the club in its many ventures and would offer support, guidance and encouragement to all.”
John Lucas, who had known Mr Lock for more than 50 years, said: “It’s such a terrible thing. He was an unbelievable guy. He would do anything for anyone.
“I can’t understand how it happened. He wouldn’t have got out of the car and caused any trouble at all.
“He wasn’t that type of guy. He has been in the cycling club - Worthing Excelsior Cycling Club - more than 60 years.”
Officers were carrying out house-to-house inquiries as locals described their shock at such an event happening in a sleepy village close to the Downs.
Laura Muchmore, 21, who works in a garden centre close to the scene, said: “It’s really shocking for an area like this.
“Nothing ever happens round here. And it’s especially shocking that the victim was an old man. Findon is a really lovely little village. It’s so picturesque and it’s not known for this type of crime.”
Another resident, who declined to be named, said: “It’s horrendous. It’s such a quiet little village and so unusual for something like this to happen.”
Police teams were carrying out fingertip searches of the undergrowth down the middle of the carriageway where the incident happened.
Mr Hibbert said: “A man is in custody on suspicion of murder.
“I continue to appeal to anyone who witnessed the collision on the A24 at 8.40pm last night, or who may have CCTV or dashboard cameras of the area at that time, to come to assist our investigation.”