If it makes you feel any better, these china bikes are lightweight, therefore the brake and clutch pads seem to last "almost" forever. I've owned these type bikes for years and many thousands of miles and have never replaced a brake pad or clutch....
Ebay is a good source for parts, I'm sure they are listed, the trick is finding them through different key word searches, like "200cc dirt bike brake pads"
maybe these?
http://www.ebay.com/itm/DIRT-BIKE-BR...lTajxh&vxp=mtr