I've got a strange problem that I've had before, but I let the guys at the LBS handle it last time I had a tune-up and they didn't say exactly what they did. It's appeared again, so I thought I'd ask here before I go spend another 100+ at the LBS.

When I upshift on my rear cassette, I don't always get into the gear I want. From 1 to 2 always works correctly, as do 6 to 7 and 7 to 8. For all the rest, though, I command the gear and the shift just doesn't happen. It *might* happen at some time later, if I'm patient (like up to a minute or so later), but usually I don't get anything. If I go one gear higher, it slips into the gear I really wanted.

For example, if I'm riding in 4 and want to go to 5, I change the shifter to 5. Nothing happens. If I change it to 6, it slips into 5. At some time later, it may go into 6 as well.

I don't have any problems downshifting; just up. If I upshift to one gear more than the one I wanted then immediately downshift, I get the gear I wanted and stay there.

To further the previous example. Say I was in 4 and wanted to be in 5 and expected to stay there for a while. I shift to 5, then to 6, then back down to 5. The bike did nothing for the shift from 4 to 5, shifted to 5 when I requested 5 to 6, then stayed in 5 when I went from 6 to 5. If it did happen to shift through 5 and into 6 when I asked for 6, then the shift down to 5 actually does a shift and I get 5 like I wanted.

Any ideas?

I have this issue with my commuter from time to time. Generally cleaning/lubing the chain and rear derailler cable fixes it.

I clean and lube the chain every Sunday afternoon. It's part of my "get ready for the work week" routine, along with washing my clothes. I don't do anything to the derailer cable, though. How would you lube that?

I remove the cable from the housing and spray dry lube into the housing end.

Check your RD cable. Could be time for replacement. Also check the cable guide under your bottom bracket, they can get gunked up.