Setting up a charity event for mountain biking?

First and foremost, I have seen your charity thread, Ozzy (and payday is in a few days
Flight Simulator and other chat
https://forums.simviation.com/phpBB3/
https://forums.simviation.com/phpBB3/viewtopic.php?f=25&t=77559
I'd always train to just over the distance, just to build up stamina. It'll be tough enough on the day without being properly prepared