Chain skipping on rear cassette... Looking for some help in diagnosing.

The first thing you should try whenever you run into shifting issues is adjusting the cable tension. Skipping is often due to the tension being too high - extra tension pulls the chain slightly onto the shift ramps for the next largest cog so that it catches them every once in a while. This lifts the chain off the cog as it tries to downshift, which you feel as a "skip." Slightly reducing the tension (about a quarter turn counterclockwise on the barrel adjuster at your shifter) will likely fix the issue.

I've tried this, but I'm obviously not an expert so maybe I didn't adjust as well as I could have. I'll take another look tonight.

The next thing to check is whether or not you have junk (grass, leaves, etc) stuck between the cassette cogs. If you've got enough packed in there, it can cause your chain to skip because it's not able to seat itself fully on the teeth of the cog.

I clean my cassette after every "dirty" ride, and use wax as a lube, so it's usually very clean, with nothing between the cogs.

It's also possible that your derailleur hanger is slightly bent. You can take your bike to the shop to have it aligned, or just replace the hanger.

I think this is what edmontonient is leading at, and something I'll have to confirm. It didn't seem bent looking at it, but I don't think I ever specifically put it in first gear and looked at the first pulley.

If none of these solves the problem, you may need a new cassette. Your cassette doesn't look excessively worn though, so I doubt this is your issue.

That's my thinking as well. A friend of mine thinks my cable may be kinked, so I'll probably try replacing the cable altogether since that's a cheap investment.

Thanks for your input!

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