The 2012 End-2-End mountain bike race has reached full capacity within a week of registration opening.
The sheer volume of cyclists wanting to compete in the 46-mile challenge saw organisers increase the event's capacity to 1,700 last year.
Organiser Steve Honeybone said: ‘The level of interest is amazing but we have to cap it for the riders' safety.’
More than 650 riders will travel to the Island to compete in the race in September.
Football: Island club wants community to design new crest and kit
Gymnasium AFC & Douglas Athletic FC merged during the summer
Boxing: Devine defeats Paredes to continue unbeaten run
Manxman moves onto 12 pro victories with unanimous points win
Athletics: Island athletes shine at British Masters
Seven-strong team claims 11 medals in Derby
Date confirmed for funeral of Sam Naughton
Isle of Man rider died following incident at this year's Manx Grand Prix