I don't take the best care of my bike. I clean the drive train occasionally but mostly I ride it into the ground. It's time for a major tune up, replace the chain, etc., but I only have two weeks until I'm gone for an extended period of time and I can leave the bike at the shop. For the last week my rear derailleur has been acting up and I couldn't get to the bottom two cogs so I worked a little harder getting up the hills. On the way in yesterday I could barely shift at all. I called a LBS and they said they could look at it during lunch. I thought it just needed an adjustment. But it's never that simple. I needed a new cable and cable guides. But while removing the cable the cable head broke off inside the shifter.
"This is bad," I was told. I'd have to leave the bike and hope they could get that piece out. Otherwise I'd have to replace the shifters which would be very expensive. Fortunately they came through and I got to ride home and shift gears with impunity. Thankfully, I get to ride for two more weeks.