I was sort of in your shoes last November, except that I'm with a small strom and am doing relatively "easy and safe" terrain in South America. But it also had 9k miles on the odo at the start of the trip.

I would give you two pieces of advice.

1. It sounds like you'll be doing a lot of miles. Spend the cash and replace ALL the consumables before you go. This means you will be replacing stuff that doesn't need replaced quite just yet - for me that's a small price to pay for the certainty. To be clear, I mean:
- tyres
- chain and sprocket
- air filter
- oil filter
- sparkplugs
- brake pads
- battery (sounds like you've done it)

2. Take the scheduled maintenance chart from your manual and place it on top of a map of your trip. Plan where you will get everything done - anything that's not on that chart but you know is consumable, plan for that as well. Getting parts on the road is not easy, and even more so on the route you're planning.

I had trouble finding something as simple as an oil filter in Santiago. Tyres are the biggest pain cause they are bulky, but some people even go as far as carting a pair with them.

I don't know how the valve clearances are done on a Sertao, but on a Strom they're done with shims and for that reason alone it's not a Round the World bike. If the Sertao has shims, it'd be a good idea to take a peek at them before you go - on a Strom they're due a peek at 14,500 miles, which is not that much into your trip. And ideally, adjust before you go - 15k miles is not that long an interval, and by opening them up before you go you'll know what shims are already in place and you can buy the right shims before you set off.

If I were setting off again, I would carry with me oil filters and spark plugs. K&N filters are a bit of a mixed blessing, but probably easier to carry a recharge kit (it's basically a bottle of cleaner and a bottle of oil) which allows you to service it on the road than a whole new filter - so you should definitely consider it.

On the rest, I think it's not unreasonable to service it exactly as BMW intended and plan on it not breaking, and then dealing with the headache if it does as and when.

Hope this helps.

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