I agree with Walter - both Uzbekistan and Tajikistan don't have much in the way of motorcycles, and even less so parts/tyres for foreign bikes.
Apart from Almaty, there is one motorcycle "shop" in Bishkek / Kyrgyzstan, run by Dima who also has a shop in Almaty. He rides a BMW 1150 himself, and will happily have TKCs or similar waiting for you if you get in touch with him beforehand. I don't have his contact details with me right now, but you'll find it when searching the HUBB. The shop is the container town west of Bishkek.