The Manx Telecom End to End Mountain Bike Challenge gets underway at 10 o'clock this morning (Sun)
Over 1,400 competitors will tackle the gruelling 75km route from the Point of Ayre to Cregneash which includes a total of 1,500 metres of climbing.
The course is a mixture of country lanes, fire road trails, moorland paths and single tracks through the plantations.
With the weather set fair, the top riders should arrive at the finish at or before one o'clock.
The event always has a legacy with new trails through Arrasey and work starting on Archallagen.
Chair of the organising committee is Kate Evans