Frank Robinson, who founded the 5-WAYS Motorcycle Centre on Walton Street, in the city, in 1980, was described as a “dearly loved and devoted husband, father and grandpa” by his family.
Mr Robinson, 67, was visiting the Isle of Man for the races as he has done every year since he was 16, when the accident happened on the A1 between Peel and Douglas on Friday.
The death toll rose to three on Saturday when sidecar driver Dwight Beare, 27, and motorcyclist Paul Shoesmith, 50, were killed during the first day of the Races.
Mr Beare and Mr Shoesmith are the 249th and 250th competitors to be killed on the Snaefell Mountain Course.
Police said Mr Robinson’s Triumph collided with a Suzuki motorcycle, with a rider and pillion passenger on board, travelling in the opposite direction, on the A1.
Members of the public gave first aid, before paramedics came, but Mr Robinson was pronounced dead on arrival at Nobles Hospital.
The pair on the Suzuki were also treated for their injuries at the scene and taken to Nobles Hospital, where they remain for treatment.
Inspector Dave Dobbie, senior investigating officer, appealed for witnesses. He said: “Investigations are continuing into this very sad incident. I would like to thank members of the public who stopped and assisted with first aid at the scene prior to the arrival of the emergency services.”
ACU Events Ltd, which organises the races, said it wished to pass its deepest sympathy to the families and friends of both Mr Beare and Mr Shoesmith.
Mr Beare, who is originally from Melbourne, Australia but lived in Onchan in the Isle of Man, was killed following an accident near Rhencullen during Saturday’s Sidecar Race 1.
He made his debut at the TT Races in 2014, achieving a 12th place in his second race on the Isle of Man when he competed with father Noel as his passenger.
The pair returned to the Isle of Man TT last year, achieving a 17th place in the first sidecar race.
His passenger this year, Benjamin Binns, from the Isle of Man, was airlifted to Nobles Hospital where he was described as being stable with a fractured ankle.
Mr Shoesmith, from Poynton, Lancashire, was killed following an accident on Sulby Straight during Saturday’s solo practice.
The session was abandoned.
He had made his debut at the TT Races in 2005 and had a highest placed finish of 15th on the TT Mountain Course in both the Superbike and Senior Races in 2011.
He also achieved finishes of 8th and 11th in the 2008 and 2009 Lightweight TT Races at the Billown circuit.
He achieved his fastest ever lap around the TT Mountain Course in Saturday’s Superbike Race, lapping at 125.896mph and finishing 29th. He won 40 bronze replicas, including the one he received for Saturday’s race.
A statement from ACU Events said: “Paul also operated his own Ice Valley Four Anjels Racing team and gave numerous riders the opportunity to compete at a high level in the TT Races including many of the current race paddock.”
The Isle of Man TT race has been run with breaks for the First and Second World Wars since 1907