Originally Posted by
Random11
One problem is that I tend to use the smaller cogs on the cassette a lot, and am not using the big cogs. In the past, every time my cassette started skipping, it was always on the 11 tooth cog. I'm hoping that by sharing that load between the 11 and 12, I can get more life from the cassette.
You can always buy single cogs to replace the high wear smaller ones although once you have to buy 3-4 or more you might as well get a whole new cassette. Here's a list of Shimano cassettes and individual cog part numbers which you can use to do a general search. Sometimes your local bike shop can order them for you or Ebay is a good source.
Manuals & Technical Documents (shimano.com)