(1) Minimum 5 inch travel bikes, in good working condition
(2) Minimum 2.1 tyres (will be going through some serious rock gardens... don't play play)
*AMENDMENT 26/10/09* Should be 2.35 tyres or bigger. Due to high levels of erosion, bigger tyres with lower pressures are needed for rock gardens, drops, steep rooty sections.
(3) 8 inch rotors - for the front at least. Ideally, both front and rear. I have spare adaptors for 8 inch rotors (various, IS to POST, POST to POST etc), so can loan that out to you guys first if you don't have it already.
(4) Shorty / stubby stem
(5) Suitably short seatpost (will usually drop the seatpost pretty much all the way - so some rear suspension may have an interrupted seattube which would prevent your normal long XC seatpost from coming down all the way).
(6) Almost forgot - PROTECTIVE GEAR. Elbow, knee/shin guards. I've also taken to wearing 'armoured' shorts, which has extra foam protectors for hips, thighs etc. Before that, I had blue blacks on the hips, despite doing ok breakfall during a spill.
I will be bringing along the floor pump, shock pump and a couple extra tubes. Best that you have extra tubes for yourself.
(7) *AMENDMENT 26/10/09* Clipless pedals with platforms are a must (e.g. Shimano M647, Crankbrother Mallets etc) Clipless pedals alone not suitable for the steep technical terrain.
(8) *AMENDMENT 3/3/10* If you have a few pairs of cycling shoes, should not use your nice-looking ones, as they will get trashed with each run. For example, a brand new pair of SIDIs will look like it has been microwaved with putty after Penang hill.