He had been living in California but died in Illinois. He was reportedly about to get on a horse when he died.
A consistent international competitor during the 1970-90s, Grubb had great success both as an individual and as a British team member at Senior Nations Cups. His first Nations Cup appearance was in 1974 at Olsztyn with his well known horse Arksey, followed by appearances throughout the late 70s and early 80s with Inchcape Chicago and Night Murmur.
It was his partnering with the bay horse Linky that gave him the highlight of his career when as a member of the British team at the 1984 Los Angeles Olympics they played a pivotal part in securing team silver alongside team mates Steven Smith and John and Michael Whitaker. Tim was also a member of the team that contested the 1980 Alternative Olympics where the team took team silver again as well as the 1992 Barcelona Olympics.
He was a member of the US team at the World Equestrian Games in 1994, and won some of the USA's most important grands prix, including the American Invitational, Devon and the Hampton Classic. He also won the American Grand Prix Association Championship and the AGA Horse of the Year title with Denizen in 1993.
Grubb started his riding career in Leicestershire as a member of his local Pony Club before working as a freelance steeplechase jockey before taking up showjumping. He then worked and rode for John Masssarella, a dealer who was the brother of the well known and incredibly successful British chef d'equipe at that time Ronnie Massarella.
British Showjumping described Grubb as "extremely likeable and charismatic".
British Showjumping chairman Michael Mac said Grubb was "not only a great ambassador for showjumping in Great Britain but also a great inspiration to all of those that knew him. I speak not only for myself but also on behalf of British Showjumping when I express our sadness at the news of his untimely death and we send our sincere condolences to his family and loved ones."