How long for a cassette?
 

I have a Shimano 9-speed cassette on my bike. I have also just passed the 10,000 mile mark on the bike over the past 17 months. What I'm wondering is, under normal circumstances, what is the range of miles one should expect a cassette to go before considering replacement?

Bob

Same chain/cassette?

The same cassette, but the second chain. The first chain was replaced at 2000 miles, but the present cassette has 8000 miles - I had it checked periodically because I've never had one last this long, but each time the shop said it was fine. But I am going to replace it next time I go by the shop anyway. I feel I've certainly gotten my money's worth from it and I don't want to press my luck!