I got OEM sprockets through munnracing.com and the DID ZVMX 525 chain from motorcyclesuperstore.com with a coupon code and that made it the lowest $$ I could find. I haven't had a coupon code for quite a while, maybe they stopped offering them? I kept the same 16/42 stock gearing but the 45t rear is actually cheaper then the 42t. I ordered the 120 link chain but should have ordered the 130 so I would have a section of chain after cutting it down to 118 links, for trail side repairs.
A mangy man chasing a cautionary tale
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KTM 990R 500EXC