Ok guys I lost it and I apologise for flipping my lid but believe me so many answers are flippant or sarcastic with little thought being put into them that I find it exasperating.
After all I didn't ask you for your opinions on how to approach the preparation for this event but how to put together a cx
Yes it is a highly competetive event, its a team elimination race like you see on extreme events on B SkyB. I can assure you this will be very fast and gruelling triathlon especially given the calibre of people doing it.
http://www.actionforcharity.co.uk/snowdonia220802.htm

It will take me a couple of days and about £150.00 to design & build Kathy a bike which will be light enough and strong enough to give her a little bit of an edge over the 3 army blokes in her team. That will be my contribution .(The team can only go as fast as the slowest team member as they are signed in at various check points around the course.)

So its not quite the `lightweight' event you assumed is it !