Former Wonder Stuff drummer Martin Gilks was seen speeding and tailgating moments before he crashed his motorbike and died, an inquest has been told.
Martin Gilks was part of the Wonder Stuff's successful 1990s line-up
In a statement, motorist Tim Dunn said he saw Mr Gilks, 41, riding like a "muppet" along Putney Bridge Road, in Wandsworth, south London, in April.
Minutes later, Mr Gilks, who had two children, came off his bike. He died the next day from multiple injuries.
The coroner recorded a verdict of traumatic road death.
Deputy Coroner Dr Shirley Radcliffe said: "He failed to negotiate the bend for some reason and clipped the kerb.
"The bike fell on its side and maintained a speed of 47mph, the riders were thrown off, fatally injuring Mr Gilks."
His pillion passenger Erica Boyle suffered a broken leg in the accident.
Westminster Coroner's Court heard how the pair had spent the day watching the Oxford and Cambridge Universities boat race.
Mr Dunn, who lives in Wandsworth, spotted them on the Kawasaki ZRX 1200 sports bike after they left a pub at about 1930 BST.
"I was watching him because he was right on my tail, speeding and going around the (central) island the wrong way.
"I was watching him to see what he would do next. He was a muppet."
He said the drummer sped away from a set of traffic lights then as he approached a bend he saw that the rider and his passenger had come off.
Witness Thomas Bissenden said: "I noticed the bike leant backwards, it slipped to the side and the bike's passenger came off, and the bike skidded in my direction."
Mr Gilks, who lived in Harlesden, north-west London, hit a metal bollard and suffered internal bleeding.
Sgt Richard Auty, from the Metropolitan Police's crash investigation unit, told the court the drummer was travelling at at least 47mph when he crashed - the speed limit on a section of the road was 30mph.
The Wonder Stuff enjoyed success in the early 1990s with hits such as The Size Of A Cow and Welcome To The Cheap Seats.
After the group split in 1994, Mr Gilks went into management, working with rock bands A, Reef and Hundred Reasons.