http://www.horizonsunlimited.com/forwood/iran2.shtml
Iran might somehow be within possibilities, but I wonder, if they´ve actually managed to do India & Pakistan without a carnet (and getting to ride their bike, not transport it in trains or something?)
Anyway, thats some pretty freakin serious traveling that they´ve done, I must say.. hats off to them!
The passes Turkey >< Iran, if your going between Dogubayazit and Maku, I dont recall it being very high. But we were coming from Dogubayazit, which is nearly 2000m above sea level, and I think the road to the border went a bit higher, but not much.
But we came from Tatvan (Lake Van), and there was the Tendurek Gecidi pass between the lake and Dogubayazit, it was around 2600 meters. And a word of warning: in that pass area, we were chased by big, mean-looking guard dogs (Caucasian, maybe?) that run after us from the houses near the road, really didnt look like they want to be scratched. That was a bit scary, and it happened only there, but several times.
I was told the main road from Iran border to Ankara also goes quite high, so winter can come early. There are alternative routes further south, that should also go at somewhat lower altitudes.