AMS is a very individual and depending mostly on your physical state, a little on mental as well. Remember the only real cure to the AMS is by going down again.

I've gotten AMS two times in my life. Once when riding from 0 meters camping on a Pacific beach in Chile to 5000 meters Altiplano in Bolivia in less than 30 hours. That was the worst one I've experienced - and my first introduction to this effect (I then lived all my life on the sealevel). Second time on the same Trans-Pamir road the thread author is planning. From Dushanbe I went up too fast, but thanfully that wasn't too bad - just a single all night of vomiting at 4000 meters (coming from 2500).

Also depends how much physical work you do - it's a big difference being in a comfortable bus or a car, or riding your motorcycle in technical steep offroad mountain track.

Remember AMS is mostly your own immune system fighting you. What I've observed the people who are more fit tend to suffer more when rushing into altitude post 3000-3500 meters - ditto on me, since my wife doesn't do any sports and she only had a mild headache when I suffered more. Ironically those who heavily smoke and drink cope much better (their immune system is weakened and lungs already used with "low" oxygen). I've talked both with Pakistani and Indian soldiers on both sides of Kashmir who still wage a secret war in Siachen glacier at around 6000 meters daily and they observed the same ironic thing - a bit fattier heavy smoker "soft" soldier copes much better than the otherwise very capable "superfit" soldier in combat operations at those extreme altitudes.

If you want to be certain then my experience is that after the critical level, for most people at 2500-3000 meters you need to sleep out the best around 500 m or max 1000 meters higher each night than the night before, over this you're pushing your luck by getting an AMS (and believe me it can come very suddenly the least when you expect it). In my experience it's mostly the sleep cycle that "sets" you to adapt to the coming altitude. You can go temporarily higher during the daytime, i.e. up to 4000 meter or more from 2.5K, but come back down 3K to sleep and continue higher the next day.

With this method I've visited most of the Indian Himalaya high passes around 5300 meters without any problems, since I knowngly planned more time to adapt with the altitude with overnight sleeps.

I've tried Acetazolamide (or known as Diamox), this may help a little to lessen the risks of getting an AMS, but can have nasty side effects. The best method is still taking a proper time to adapt with the gradual sleep cycles IMO.

PS: if you like more offroad a great alternative is head down from Khorog to Wakhan corridor. It's a great gravel track and you can take a good look into Afghanistan on the opposite side of the Panj river. We loved it. The road starts to climb quickly if you leave the Panj behind from 3000 meters on the way to Alichur around 4000 meters - plan a good camping or two on the way.

Some pictures and words here: http://advrider.com/index.php?thread...80532/page-148