I had about 23,000 miles on the OEM when I changed it out sprockets too.
Got about 7,000 on the RK I put on and seems to be wearing just fine.
FYI 4 rears (OEM Metz 9k, Bridgestone S11 10K, STINKo 4k, and MC2 going strong at abot 7K) 2 fronts (OEM Metz changed when I changed my first rear but didn't need it and now still on same Bridgstone S11, gonna replace it soon)
