Having just come back from Italy I went through the same pre trip question. Here’s what I did….
Serviced the rear shock (Mojo – it hadn’t been done for just over a year) & fork lowers (myself)
New rear wheel – the freehub was on it’s way out & turned out that it wouldn’t come off (to be replaced) so a new wheel was needed
Stripped, checked bearings & re-greased suspension pivots
Swapped my tyres to a set on Maxxis Minnon dual ply DH tyres & corresponding DH tubes
Fitted new brake pads & checked if the brakes needed bleeding (they are quite new so didn’t need it)
Chopped a bit off my seatpost to run it very low
I took the following spares: –
6 tubes (I ended up giving most of these away – I was amazed at how many people turned up with few spares)
4 sets of brake pads (I went through nearly 4 full sets in total, so brought back 2 pairs unused)
Tyres (pair)
Spokes (at least 8 – some front, some rear wheel)
Mech Hangers (I have somehow managed to end up with 4!)
Derailleur (rear)
Bottom Bracket
Gear Cables (2)
Brake lever clamps (I seem to have a habit of breaking these)
Any spares you buy there will cost close to double the UK price (I learnt this to my cost when I had to shell out nearly £50 for two pairs of brake pads in Switzerland last year)
Not sure if you’re diving or flying, but if flying take some time to pack your bike carefully (I took off all of the following & packed them carefully: rotors (packed between 2 sheets of stiff cardboard), rear mech, mech hanger, pedals). I made sure I put pad spacers in the brake calipers. I used plenty of bubble wrap & some pipe lagging from the DIY store. I also strapped my knee/elbow pads to the bike.
Sometimes the problems you get aren’t the ones you expect – on the trip I was on one of the guys had problems with the rear wheel thru-axle coming loose – at one stage he had to get somebody to ride behind him to check it was staying in place!
I’ve also been advised in the past to consider using an appropriate threadlocker to secure the various bolts of the bike to stop them being shaken loose (not actually done this – haven’t had a problem)