Tyres in Kathmandu for Africa Twin
 

I'm looking to pick up new Tyres while in Kathmandu, before I head back into India onward to Assam, Arunchal Pradesh, Bangladesh.

Mixed purpose tyres should do just fine. Wont need knobby ones until I get into Kazakhstan I think.

Any leads much appreciated.

Front 140/80/R17
Rear 90/90/R21

Tyres, like bikes and all other spares are very expensive in Nepal, due to 300 Percent import duty, you could try www.hambrobazaar.com, a sort of Nepali ebay, if your desperate, otherwise I'd wait 'till your back in India for a better choice/price.
UB.

Thanks UselessB. A mechanic in India told me to wait until Kathmandu because it would be cheaper and I had some tread left. I guess he was woefully mistaken. Lame.

Other possible option: I'm actually headed back to the US for a wedding, leaving the bike elsewhere while gone.

Would I be allowed to bring tyres back into Nepal on my return trip?

Yeah im pretty sure would, KTM airport is chaos and you see people bringing in all sorts of stuff,

or take a really big suitcase?