Enniskillen man Noble has been struggling with a knee injury in the lead up to the London Games which will require an operation after the Olympics but nothing was going to stop Gavin competing against the 54 other top triathletes in the world.
The event will start with the competitors swimming one lap of the Serpentine Swimming Club which is 1500m and this is then followed by a 43km, seven lap bike ride which will take the triathletes past Buckingham Palace.
And the gruelling race is then concluded with a 10km, four lap run which will finish in front of the grandstand on the Western end of Serpentine Road.
Noble admits that if it was not the Olympics then he might not participate in the race but this is one that he was not going to miss out on.
"I've been struggling all year, but it's the Olympics and I'm not going to wimp out now," he commented.
And the Fermanagh man is also realistic in his aim for tomorrow's event.
"I am realistic enough to know that I won't win a medal. It's not a very difficult or challenging course and it's the Olympics so it is going to be very, very fast. I want to be in the lead pack at the end of the bike. Hopefully if that goes well it won't be all 55 guys in the pack and there will be gaps behind us, and then if I can hold on during the run then I will be very happy," he said.