I would suggest a good tool kit would be worth investing in.
But if you really want to do a hard mountain bike ride, then i can heartily reccomend this:
http://www.grand-raid-cristalp.ch/www/GRC/grc.nsf/99a34670a5962fba412567970035ceaa/3b6aa54edc05295141256bd0005694ab!OpenDocument
I can say this was probably the hardest thing i have done!