When I rode to Everest basecamp on the China side in summer 2009 there wasn't much pavement for last 50km, just washboard gravel. The route appears to get alot of military traffic and it is a sensitive border area (more so along China-India border). So what pavement that does exist serves a purpose beyond serving the climbers and the occasional biker. When Everest first comes into view it is a religious moment.
2005 BMW 1200GS, 2011 Ducati 1100