SITS is organised by Pro Velo Support, also responsible for the legendary Mountain Mayhem, and so benefits from the same enthusiasm and attention to detail but with a slightly more relaxed feel. And, according to the website, entries are still being taken.
The Manx Mountain Bike Clubs Enduro Series is an event that can be either 3, 2 or 1 hours in duration. The aim is to get as many laps around the course as you can within the time limit you have chosen for yourself.